1 FATTY ACIDS in PHOTOTROPHIC and MIXOTROPHIC GYRODINIUM GALATHE- ANUM (DINOPHYCEAE) Adolf, J. E.1, Place, A. R.2, Lund, E.2, St

PSA ABSTRACTS 1

1 Texas south jetty was completed between April 1999 FATTY ACIDS IN PHOTOTROPHIC AND and February, 2000. Species composition, seasonal pe- MIXOTROPHIC GYRODINIUM GALATHE- riodicity, and fluctuations in temperature and salinity ANUM (DINOPHYCEAE) were determined. This is the first comprehensive 1 2 2 study of benthic macroalgae conducted in Corpus Adolf, J. E. , Place, A. R. , Lund, E. , Stoecker, Christi Bay, which is shallow, turbid, and lacks natural 1 1,3 D. K. , & Harding, L. W., Jr hard substrate. Man-made jetties are necessary for 1Horn Point Lab, University of Maryland Center for suitable floral attachment. Macroalgae are affected by Environmental Science, Cambridge, MD 21613 USA; changes in salinity as freshwater inflows are followed 2Center of Marine Biotechnology, Baltimore, MD 21202 by periods of drought, which increase salinity. These USA; 3Maryland Sea Grant, University of Maryland, effects are most notable where freshwater enters at College Park, MD 20742 USA the south end near Oso Bay and at the north end at Nueces Bay. Previous Texas algal collections de- Fatty acids were measured in G. galatheanum grown scribed species of Enteromorpha, Ulva, Gelidium, and either phototrophically, or mixotrophically with Gracilaria as the most dominant plants of the area. Storeatula major (Cryptophyceae) as prey. G. galatheanum, This supports the current study with the additions of like many photosynthetic dinoflagellates, contains Hypnea musciformis and Centroceras clavulatum. Domi- high amounts of n-3 long-chain-polyunsaturated fatty nant plants at the Port Aransas jetty include Ulva fasci- acids (LC-PUFA) such as docosahexaenoic acid ata, Padina gymnospora, and Hypnea musciformis. The (DHA, 22:6n-3) and the hemolytic toxic fatty acid Rhodophyta including Gracilaria, Gelidium, and Centro- 18:5n-3. We hypothesize that a benefit of phagotrophy ceras clavulatum dominate the bay and do so through- in G. galatheanum is the acquisition of precursor lino- out the year. Chlorophytes, although few in species lenic acid (18:3n-3) that fuels LC-PUFA synthesis. richness, are important to benthic coverage and bio- Phototrophs grew at 0.37 dϪ1, while mixotrophs grew mass. Phaeophyta are found predominantly at the at 0.40 dϪ1 with a feeding rate of 0.62 dϪ1. Photosyn- Port Aransas jetty with Sargassum, Dictyota dichotoma, thesis was lower in mixotrophs (3.7 pg C cellϪ1 hϪ1) and Petalonia fascia being most abundant. A transition than phototrophs (4.9 pg C cellϪ1 hϪ1). DHA levels occurs in species composition as the water tempera- were higher in mixotrophs [3.7 (ϩ/Ϫ 0.11) pg cellϪ1] ture changes seasonally. Hincksia, Ectocarpus, and Peta- than phototrophs [3.0 (ϩ/Ϫ 0.16) pg cellϪ1] and lonia fascia are found only during the cooler months. prey [0.4 (ϩ/Ϫ 0.01) pg cellϪ1]. 18:5n–3 levels [1.7 (ϩ/Ϫ 0.03) pg cellϪ1] were similar in phototrophs 3 and mixotrophs. An intermediate in n-3 LC-PUFA NEW AND RARE CHRYSOPHYTES FROM synthesis, 20:4n-3, accumulated in mixotrophs [0.6 WYOMING AND COLORADO LAKES (ϩ/Ϫ 0.27) pg cellϪ1] relative to phototrophs (not Ϫ1 Aguiar, R. & Kugrens, P. detected) and prey [0.03 (ϩ/Ϫ 0.002) pg cell ]. Low Department of Biology, Colorado State University, Fort ratios of linolenic acid to DHA in phototrophic G. Collins, Colorado 80523 USA galatheanum (0.14) relative to mixotrophic G. galatheanum (0.29) and prey (2.14) are consistent with substrate limitation of LC-PUFA synthesis in phototro- Colorado and Wyoming lakes with high pH values phs. Accumulation of 20:4n-3 suggests incomplete generally ranging from 8 to 10 are dominated by phy- conversion of linolenic acid to DHA, possibly due to toplankton belonging to the chrysophytes, diatoms conditions in batch culture. We conclude that precur- and cryptomonads. Our studies on phytoplankton di- sors for n-3 LC-PUFA biosynthesis in G. galatheanum versity in Dowdy, South Delaney Buttes and Cowdrey may be acquired through ingestion of S. major, and Lakes in Colorado and Diamond and Twin Buttes may partially control feeding/photosynthesis in mix- Lakes in Wyoming have yielded several isolates of rare otrophic populations. or new chrysophytes. These isolates were examined with light microscopy, SEM, TEM, and novel information regarding their structure is presented. Proposed 2 new species belong to the genera Saccochrysis, Prymne- SPECIES COMPOSITION AND SEASONAL sium and Chrysochromulina. Chrysophytes that were ex- PERIODICITY OF MACROALGAL SPECIES IN amined for the first time include Monochrysis aphanas- CORPUS CHRISTI BAY, TEXAS ter, Uroglenopsis, and a mixotrophic species of Ochromonas, which ingests small diatoms. Probable Agan, J. C. & Lehman, R. L. new species are the following: Saccochrysis sp. nov. dif- Department of Physical and Life Sciences, Texas A&M fers in chloroplast structure, cell shape and cell num- University-Corpus Christi, 6300 Ocean Dr., Corpus ber/colony, and absence of a posterior vacuole; Prym- Christi, TX 78412 USA nesium sp. nov. is the first freshwater form examined with EM and differs in scale morphology; and Chryso- Benthic algal sampling from selected sites along Cor- chromulina sp. nov. is similar to Chrysochromulina parva pus Christi Bay and from one site at the Port Aransas, but lacks scales. The ultrastructure of M. aphanaster is

2 PSA ABSTRACTS unique and appears to be a member of the Chryso- Wilmington, NC 28403 USA; 3Department of Phycol- phyceae. It has two flagella, one of which is emergent, ogy, University of Copenhagen, Copenhagen, Denmark while the other is hidden within an invagination of the cytoplasm. Diacronema and Sarcinochrysis spp. from The Phaeothamniophyceae was based upon ultra- these lakes also were isolated and reinvestigated, and structure, pigment analysis and rbcL gene sequences. some unique cellular features will be discussed. Recently we have successfully obtained SSU rDNA sequences from members of this relatively new class. 4 These sequences corroborate the phylogenetic relationship of the Phaeothamniophyceae as a close rela- ALGAL COMMUNITY STRUCTURE OF THE tive of the Phaeophyceae and Xanthophyceae. Addi- EAST AND WEST FLOWER GARDEN BANKS, tionally we show that the “walled” Chrysocapsa NORTHWESTERN GULF OF MEXICO epiphytica is a synonmym of Tetrasporopsis fuscescens and Albert, E. M. & Lehman, R. L. belongs in the Phaeothamniophyceae. Conversely, Center for Coastal Studies, Texas A&M University- “wall-less” taxa such as Chrysocapsa vernalis, Dermatochry- Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX sis, and Chrysonebula belong within the Chryso- 78412 USA phyceae. Furthermore, we suggest that the capsoid Tetrachrysis dendroides is a synonym of Stichogloea globosa The algal communities of the Flower Garden Banks and belongs within the Phaeothamniophyceae. We National Marine Sanctuary have not been compre- will also report new findings for other genera (e.g. hensively evaluated and only a few dominant macroal- Phaeobotrys, Phaeothamnion, Phaeoschizochlamys, Stichog- gal species have been reported. This study utilizes loea). It appears that the capsoid habit evolved inde- both destructive and non-destructive sampling tech- pendently in the Phaeothamniophyceae and the niques to characterize and taxonomically identify the Chrysophyceae, thus providing a new example of con- ‘algal mat’ community structure. The East and West vergent evolution for thallus organization. Flower Garden Banks are located on the outer continental shelf approximately 200 km off the Texas-Loui- siana coastline. The average depth of both banks is 6 100 m with the crest approximately 20 m from the surface. Harvest and photogrammetric samples were col- RELATIVE IMPORTANCE OF RECRUIT- lected during two extended cruises to the Flower Gar- MENT VERSUS REGENERATION IN MAIN- den Banks in October 1998 and March 1999. Forty, TAINING THE POPULATIONS OF SAR- 0.25-m2 quadrats of standing stock material were ran- GASSUM HENSLOWIANUM IN PING CHAU, domly collected along with one hundred sixty-one HONG KONG 0.25 m2 photo-quadrats from an average depth of 27 Ang, P. O. m. Photo-transparencies were projected to an actual Department of Biology, The Chinese University of Hong size grid with 25 random points. Four thousand Kong, Shatin, N.T., Hong Kong SAR, China twenty-five transparency points were evaluated and used to calculate percent composition of algal cover. Populations S. henslowianum dominate the shallow Harvest samples were used to characterize the “algal subtidal waters of Ping Chau Island, Hong Kong. A mat” composition, species richness, abundance, and study was carried out to evaluate the relative impor- biomass. Forty-two species were identified from the tance of recruitment vs regeneration from the hold- samples representing 14 Orders. The “red algal mat” fast in the maintenance of these populations. The was the dominant algal coverage comprising 38.4% of number of recruits on clearings, artificial and natural all photogrammetric samples. This mat was primarily substrata as well as the density of the natural popula- composed of members from the Order Ceramiales. tions were evaluated on a periodic basis from March Centroceras, Ceramium, and Polysiphonia comprised 1998 to March 2000. The results indicated that al- 33.4% of the mat, Anotrichium and Hypoglossum, though up to 85 to 100% of the individuals of this spe- 22.4%. cies may be reproductive during the winter reproductive season (Nov to Feb), only up to a maximum mean 5 density of 17 recruits 0.25 mϪ2 were found in the THE PHYLOGENETIC RELATIONSHIPS OF cleared areas or artificial substrata provided. Less THE PHAEOTHAMNIOPHYCEAE, WITH than 10% of these eventually survived the following growth season. In the natural stands, new individuals COMMENTS ON CERTAIN CAPSOID MEM- (recruits) constituted only less than 15% of the mean BERS OF THE CHRYSOPHYCEAE density. The number of new recruits was particularly 1 2 3 Andersen, R. A. , Bailey, J. C. & Daugbjerg, N. low around older individuals. Thus, these populations 1Bigelow Laboratory for Ocean Sciences, West Boothbay were mainly made up of older individuals regenerat- Harbor, ME 04575 USA; 2Department of Biological ing from their perennating holdfasts. It appears that Sciences, University of North Carolina-Wilmington, regeneration from the holdfast is a far more impor-

PSA ABSTRACTS 3 tant strategy than recruitment in the maintenance of 1Departamento de Ciencias Básicas, Universidad del these populations. Bío-Bío, Chillán, Chile, 2Department of Botany, Uni- versity of Toronto, Toronto, ON M5S 3B2 Canada, 3Department of Plant Pathology, University of Wiscon- 7 sin, Madison, WI 53706 USA, 4Department of Botany, IN VIVO CHARACTERIZATION OF THE DIA- University of Wisconsin, Madison, WI 53706 USA TOM MULTIPARTATE PLASTID TARGET- ING SIGNAL Mougeotia sp, a dominant component of a metaphytic Apt, K. E.1, Zaslavskaia, L.1, Lippmeier, J. C.1, algal bloom-forming alga in an experimentally acidi- Lang, M.2, Grossman, A. R.3, & Kroth, P. G.2 fied lake (Little Rock Lake, Vilas Co. WI) was isolated 1Martek Biosciences Corp., Columbia, MD, USA; to analyze pH effects on carbonic anhydrase (CA) ac- 2Institut fur Biochemie der Pflanzen, Heinrich-Heine- tivity, localization, and algal morphology. A potentio- Universitat, Dusseldorf, Germany; 3Carnegie Institu- metric method was used to assess internal and external tion of Washington, Department of Plant Biology, CA activities using two CA inhibitors, ethoxyzolamide Stanford, CA, USA (EZA) and acetazolamide (AZA) in cultures grown at pH 5 and pH 8. External and total CA activities at pH 8 were significantly greater than those at pH 5, but in- Diatoms and related algae have plastids that are sur- ternal CA activities were not significantly different at rounded by four membranes. The outer two mem- both pH levels. The non-penetrating inhibitor AZA branes are continuous with the endoplasmic reticu- inhibited external CA activity at pH 8, whereas EZA, lum and the inner two membranes are analogous to which inhibits internal CA activity in some green al- the plastid envelope membranes of higher plants and gae, did not inhibit Mougeotia CA activity, possibly be- green algae. Thus the plastids are completely com- cause of permeability problems. Ultrastructural im- partmentalized within the ER membranes. The target- munogold labeling with a polyclonal antibody for ing presequences for nuclear-encoded plastid pro- Chlamydomonas external CA suggested that an antigen- teins have two recognizable domains. The first domain ically-similar enzyme was located in the periplasmic is a classic signal sequence, which presumably targets space and inflated end walls of Mougeotia grown at the proteins to the endoplasmic reticulum. The sec- both pHs. This antibody, labeled the Mougeotia chlo- ond domain has characteristics of a transit peptide, roplast, but not the pyrenoid and cytoplasmic periph- which targets proteins to the plastids of higher plants. eral regions. Activity measurements, inhibitor results, To characterize these targeting domains, the prese- and localization data were consistent with the opera- quence from the nuclear-encoded plastid protein tion of a carbon concentrating mechanism (CCM) at AtpC was utilized. A series of deletions of this prese- both pH levels. Growth form, cell dimensions, chloro- quence were fused to Green Fluorescent Protein plast morphology, and cell wall ultrastructure were (GFP) and transformed into cells of the diatom, Phae- significantly different in cultures grown at both pH odactylum tricornutum. The intracelluar localization of levels. These features probably contributed to the GFP was visualized by fluorescence microscopy. This ability of Mougeotia to form blooms in acidified waters. work demonstrates that the first domain of the prese- A polyclonal antibody to pea chloroplast CA did not quence is responsible for targeting proteins to the ER label Mougeotia, suggesting evolutionarily significant lumen and is the essential first step in the plastid pro- differences in the plastid CA systems of this alga and tein import process. The second domain is responsi- higher land plants. ble to directing proteins from the ER and through the plastid envelope and only a short portion of the transit peptide-like domain is necessary to complete this 9 second processing step. In vivo data generated from THE PRESENCE OF CALLOSE IN THE PRI- this study in a fully homologous transformation sys- MARY ZYGOTE WALL OF CHLAMYDOMONAS tem has confirmed Gibbs’ hypothesis regarding a MONOICA AND THE EFFECTS OF ITS DEGRA- multistep import process for plastid proteins in chro- DATION ON ZYGOTE DEVELOPMENT mophytic algae. Bai, M. S. & VanWinkle-Swift, K. P. Department of Biological Sciences, Northern Arizona 8 University, Flagstaff, AZ 86011 THE ROLE OF CARBONIC ANHYDRASE IN Chlamydomonas monoica constructs a temporary pri- THE FORMATION OF MOUGEOTIA (CHARO- mary wall around its developing zygotes. This study PHYCEAE) BLOOMS IN ACIDIC ENVIRON- aimed to confirm callose as a component of the pri- MENTS mary wall, as well as to note the effects of primary wall Arancibia-Avila, P. E.1, Coleman, J. R.2, Russin, degradation on zygote development. Glucanase, spe- W. A.3, Wilcox, L. W.4, Graham, J. M.4 & Graham, cific for the ␤-1,3 glycosidic bonds comprising callose, L. E.4 was added to mating media at concentrations ranging 4 PSA ABSTRACTS from 5 to 1 mg mlϪ1 and light microscope observa- by the presence of secondary pit connections are tions were made as the zygotes developed. The overall closely related. For example, both data sets robustly health of the zygotes was assessed by comparing their support a sister taxon relationship between Amphiroa ability to germinate after exposure to chloroform va- and Titanoderma. Our results indicate that: 1) all taxa pors. The bright staining of the primary wall with in which secondary pit connections are present aniline blue, specific for ␤-1,3 polysaccharides, sug- should be referred to the Lithophylloideae and, 2) gested the presence of callose. This was further sup- genicula are nonhomologous structures that are inde- ported by the adverse effects of glucanase on zygote pendently derived in Amphiroa, Lithothrix, Metagonioli- development. After mating, declining levels of intact thon and the last common ancestor of the Coralli- zygotes were found as their maturation continued, noideae. and dead immature zygotes accumulated in the treated cultures. Twelve days after mating, when the zygotes were plated for germination, fully mature zy- 11 gotes were identified in only the lowest of the six en- MOLECULAR SYSTEMATICS OF THE XAN- zyme concentrations. In addition, germinating zygotes from the treated cultures showed increased THOPHYCEAE 1 1 2 sensitivity to killing by chloroform vapors relative to Bailey, J. C. , McElhinney, A. L. & Andersen, R. A. untreated zygotes. These results suggest that callose is 1Department of Biological Sciences, UNC-Wilmington, a key component in the primary zygote wall, and that Wilmington, NC 28403 USA; 2Bigelow Laboratory for its degradation negatively affects zygote maturation. Ocean Sciences, West Boothbay Harbor, ME 04575 Electron microscopy will be used to help determine USA whether structural defects in the primary wall occur as a result of glucanase treatment, and whether such de- Species belonging to the Xanthophyceae have tradi- fects affect secondary zygospore wall assembly. tionally been classified in six (or seven) orders corresponding to amoeboid, coccoid, filamentous, mona- 10 doid, palmelloid and siphonous lines of descent. We PHYLOGENY AND CLASSIFICATION OF have determined plastid rbcL and nuclear 18S rRNA REEF-BUILDING CORALLINE ALGAE (COR- gene sequences for selected coccoid, filamentous and ALLINALES, RHODOPHYTA) siphonous species. Phylogenetic trees inferred from Bailey, J.C. & Freshwater, D.W. these data indicate that the orders Mischococcales Department of Biological Sciences and Center for Ma- (coccoid) and Tribonematales (filamentous) are not monophyletic. Instead, our results indicate that coc- rine Science, The University of North Carolina at coid and filamentous life forms have arisen indepen- Wilmington, Wilmington, NC 28403 USA dently in different xanthophyte lineages. Some coccoid and filamentous species are resolved as close The Corallinales includes ca. 40 genera of calcified allies. For example, in our analyses coccoid and fila- red seaweeds. Species are of two distinct morpho- mentous species possessing bipartite cell walls (e.g., types; those that possess genicula (uncalcified nodes) Bumilleria, Ophiocytium, Tribonema, Xanthonema) form and those that lack genicula. Most nongeniculate spe- a distinct and previously unrecognized lineage within cies take the form of crusts. The presence (or ab- the class. The phylogenetic positions of Asterosiphon, sence) of genicula, secondary pit connections, and Botrydium and Vaucheria are not robustly resolved, but tetrasporangial conceptacle features have tradition- our data suggest that these siphonous xanthophytes ally been used as key characters for delimiting coral- probably do not form a monophyletic group. Our re- line subfamilies. In this study, nuclear encoded 18S sults imply that Vaucheria is only distantly related to and 26S rRNA gene sequences were determined and other xanthophytes we have examined. Nucleotide se- used to reexamine relationships among coralline quence divergence values among Vaucheria species taxa. Separate and combined phylogenetic analyses of were found to be equal to, or greater than, those ob- these data yielded similar trees in which four major served between other xanthophyte species that are lineages are resolved. Heydrichia and Sporolithon classified in different families or orders. Furthermore, (Sporolithaceae) are positioned at the base of the our trees do not always support the infrageneric sys- tree and appear to be distantly related to other spe- tem of classification for Vaucheria species, which is cies examined. Within the Corallinaceae, the nongen- based primarily upon antheridial features. iculate Melobesioideae is resolved as a monophyletic group. All members of this subfamily produce mutipo- rate tetraspoangial conceptacles. The Corallinoideae, 12 which are characterized by unizonate genicula, are resolved as sister to a clade containing species placed CELL CYCLE REGULATORS IN THE FLOR- in the Lithophylloideae, Mastophoroideae and Me- IDA RED TIDE DINOFLAGELLATE, GYMNOD- tagoniolithoideae. The molecular data indicate that INIUM BREVE geniculate and nongeniculate species characterized Barbier, M., Leighfield, T. A., & Van Dolah, F. M. PSA ABSTRACTS 5

Marine Biotoxins Program, Center for Coastal Envi- lates implicated in fish mortality, little attention has ronmental Health and Biomolecular Research, NOAA, been paid the to the identities of the smaller flagel- National Ocean Service, Charleston, SC 29412 USA lates observed growing in the sea and their possible contribution to the fish and bird population mortal- The diel cycle is a key regulator of the cell cycle in ity. Using freshly collected field samples as well as en- many dinoflagellates, and may play a rate limiting role richment culture techniques, we report the occur- in bloom formation. Diel phasing of the cell cycle in rence of several genera of cryptomonads in the Salton the Florida red tide dinoflagellate, Gymnodinium breve Sea, including representatives from the genera Chroomo- Davis was previously described in our laboratory. In nas, Hemiselmis, Leucocryptos, Plagioselmis, Storeatula and cultures grown on a 16:8 light:dark cycle, S-phase be- Teleaulax. gan 6–8 h into the light phase, and mitosis followed 12–14 h later. The dark/light “dawn” transition was 14 found to provide the diel cue that serves to entrain STRUCTURE, COMPOSITION AND BIOGEN- the G. breve cell cycle. However the cell cycle mecha- ESIS OF PRASINOPHYTE SCALES nisms and regulators acted upon by this cue are poorly understood in dinoflagellates. The cell cycle Becker, B. regulatory complex, CDK1-cyclinB, is therefore cur- Botanical Institute, University of Cologne, Gyrhofstr. rently being investigated. Cyclin dependent kinase 15, 50931 Cologne, Germany (CDK) was first identified in G. breve using two approaches: (1) identification of a 34 kDa protein im- The cell body and flagellar surfaces of prasinophytes munoreactive to an antibody raised against a con- are covered by non-mineralyzed scales. Scales consist served amino acid sequence unique to the CDK mainly of acidic polysaccharides containing large protein family (PSTAIR) and (2) inhibition of the cell amounts of 2-keto sugar acids. Glycoproteins are mi- cycle by olomoucine, a selective CDK inhibitor. Sev- nor components and probably mainly involved in me- eral approaches are currently being employed in or- diating scale-subunit and scale-membrane interac- der to describe its partner, cyclin B: (1) PCR on ge- tions. In thecate prasinophytes the cell body scales nomic DNA with primers deduced from known cyclin coalesce to form a rigid cell wall, generally known as a box sequences, (2) G. breve expression library screen- theca. We have studied the polysaccharides and glyco- ing with an antibody raised against the fission yeast cy- proteins of the thecate prasinophytes Tetraselmis stri- clin B (3) western blot analysis on whole protein ex- ata and Scherffelia dubia over the last years. New results tracts and cyclin B immunoprecipitated proteins. regarding the structure of carbohydrates and proteins Current work focuses on the differential expression of will be presented. the cyclin B homologue in G. breve during its cell cycle and its relation to diel cycle control. 15 PHYLOGENY OF ATLANTIC SPECIES OF 13 GRACILARIACEAE (RHODOPHYTA) BASED PHYTOFLAGELLATES OF THE SALTON SEA: ON SMALL SUBUNIT RIBOSOMAL GENE CRYPTOPHYCEAE SEQUENCING Barlow, S.B.1 & Kugrens, P.2 Bellorin, A. M.1,2, Oliveira, M. C.1 & Oliveira, E. C.1 1Electron Microscope Facility, San Diego State Univer- 1Dept. de Botânica, Instituto de Biociências, Univer- sity, San Diego CA 92182 USA; 2Department of Biology, sidade de São Paulo, Caixa Postal 11461, São Paulo, Colorado State University, Fort Collins, Co 80523 USA Brazil; 2Dept. de Biologia, Universidad de Oriente, AP 245 Venezuela. The species composition of phytoflagellates in the Sal- ton Sea has recently been the subject of intense inves- The complete small subunit ribosomal nuclear gene tigation as part of an analysis of the Salton Sea ecosys- (ssu rDNA) sequence was determined for nine species tem. The Salton Sea, an inland sea occupying 980 km2 of Gracilaria and one species of Gracilariopsis which are in southern California, has become a major stopping common on the American Atlantic waters. The se- point for migratory birds along the Pacific Flyway. quences were aligned using the secondary structure as The increasing salinity of the sea, currently at 44 gm reference, including the published sequences of nine LϪ1, and its eutrophic condition (average depth is other species of Gracilariaceae. A matrix of 1736 sites nine meters, with a high nutrient load contributed by was constructed with a proportion of 91% invariable agricultural drainage from the surrounding farm- sites and very few assumed indels events. All the in- lands) have contributed to a stressed ecosystem. Mas- ferred trees show three main lineages: 1) the strongly sive fish kills and bird kills, including such endan- divergent lineages of Gracilariopsis; 2) the austral gen- gered birds as the brown pelican, have become a era Curdiea/Melanthalia; and 3) the lineage of recurring problem. Although previous investigations Gracilaria sensu stricto. The later encompasses the fol- have noted the presence of at least two phytoflagel- lowing groups: 1) Gracilaria chilensis from the Pacific 6 PSA ABSTRACTS ocean; 2) a group of cylindrical tropical species with Ulva pertusa, red algal turf (a mixed stand of Gigartina “henriquesiana” spermatangial type; 3) a group of intermedia and Gigartina teedii) and species of Entero- warm temperate cylindrical species with “verrucosa” morpha with highly opportunistic occurrence. To in- spermatangial type; and 4) a group of flattened tropi- vestigate their interspecific interactions, a field exper- cal species with mainly “textorii” spermatangial type. iment was carried out using press effect of one species The relationship of a species described as Gracilaria removal from permanent plots (20 x 20cm) set up on pauciramosa from Venezuela was not inequivocally two different tidal heights. Mechanisms of interaction solved. The inferred phylogenetic groups are congru- were also attempted using artificial plants to test the ent with morphology and quality of agar. possible effects of shading, scouring, allelopathy of U. pertusa on the turf algae. The turf-forming red algae 16 lowered the abundance of U. pertusa presumably by in- ARE SPERM LIMITING IN THE SEA? hibiting the recruitment of U. pertusa; this effect was Berndt, M. L. & Brawley, S. H. consistent along the tidal height. However, the greater abundance of Enteromorpha was observed in School of Marine Sciences, University of Maine, Orono, the presence of turf in the upper zone, indicating a ME 04469 USA positive effect of turf on Enteromorpha. Once U. pertusa was successfully recruited and grown to the adult The reproductive success of marine species with ex- plant, it inhibited the growth of turf by shading, ternal fertilization depends on environmental condi- which was effective both in winter and summer re- tions during gamete release. There is special interest gardless of desiccation stress. No scouring and allelo- presently in whether water motion causes sperm limi- pathic effects of U. pertusa on the turf were detected. tation under natural conditions. We investigated ga- When an open substrate was provided, Enteromorpha mete release of Fucus vesiculosus from an exposed colonized the space faster than any other species in shore to ascertain: 1) when gametes are released dur- the upper zone, but the turf was the fastest one fol- ing the tidal cycle, 2) when fertilization occurs, and 3) lowed by U. pertusa and Enteromorpha in the lower what the natural sperm:egg ratios are. Water samples zone. Results indicated that patterns of interaction were collected and concentrated over five minutes ev- represented a complex network with no ultimate win- ery half hour off Pemaquid Point, ME from three rep- ner and the outcomes of interaction varied over time licate sites within each of two locations using a pump- and space. filter device. Immunofluorescence microscopy revealed that gamete release occurred only on the two calmest spring tides. Sperm became present in the water column at the same time as oogonia (30 minϪ1 h 18 prior to high tide [HT]) and reached peak concentra- USING RDNA GENES TO UNDERSTAND THE tion at exactly HT. The sperm:egg ratio was 76:1 on 8 ORIGIN AND EVOLUTION OF SPLICEOSO- Oct 1999 and 21:1 on 8 Nov 1999 at exactly 30 min MAL AND GROUP I INTRONS prior to HT and dropped sharply after HT. Gametes Bhattacharya, D.1, Lutzoni, F.2, Reeb, V.2, Simon, continued to be collected for several hours after HT D.1, Fernandez, F.2, & Friedl, T.3 but analysis of pronuclear position in aceto-iron-he- 1Department of Biological Sciences, University of Iowa, matoxylin stained eggs revealed that all fertilization 2 occurred at approximately HT. We modelled the total Iowa City, IA 52242 USA; Department of Botany, number of days when reproduction was possible using The Field Museum of Natural History, Chicago, IL these results and wind and wave data from the Na- 60605 USA; 3Abt. Experimentelle Phykologie und Sam- tional Data Buoy Center. Our research provides evi- mlung von Algenkulturen, Universität Göttingen, dence that gamete release by F. vesiculosus occurs at 37073 Göttingen, Germany slack HT on calm days and that sperm are not a limiting factor in fertilization for this species. Ribosomal DNA genes in lichen algae and lichen fungi are astonishingly rich in spliceosomal and 17 group I introns. We use phylogenetic, secondary PATTERNS OF INTERSPECIFIC INTERAC- structure, and biochemical analyses to understand the TIONS IN THE ULVA-DOMINATED INTER- evolution of these introns. Despite the widespread dis- TIDAL COMMUNITY IN A SOUTHERN tribution of spliceosomal introns in nuclear pre- mRNA genes, their general mechanism of origin re- COAST OF KOREA mains an open question because few proven cases of Bhang, Y. J. & Kim, J. H. recent and pervasive intron origin have been docu- Department of Biological Science, Sungkyunkwan Uni- mented. The lichen introns are valuable in this re- versity, Suwon, 440-746 Korea spect because they are undoubtedly of a “recent” origin and limited to the Euascomycetes. Our analyses In the southern coast of Korea, rocky intertidal zones suggest that rDNA spliceosomal introns have arisen where green tide commonly occurs are dominated by through aberrant reverse-splicing (in trans) of free PSA ABSTRACTS 7 pre-mRNA introns into rRNAs. We propose that the 20 spliceosome itself (and not an external agent; e.g. A RE-EVALUATION OF CORALLINE RED transposable elements, group II introns) has given ALGAL TAXONOMY USING ULTRA-STRUC- rise to the introns. The rDNA introns are found most TURAL INFORMATION often between the flanking sequence G (78%) - intron-G (72%), and their clustered positions on sec- Broadwater, S. & Scott, J. ondary structures suggest that particular rRNA re- Department of Biology, College of William and Mary, gions are preferred sites (i.e., proto-splice sites) for Williamsburg, VA 23187 USA insertion. Mapping of intron positions on the newly available tertiary structures show that they are found Two competing subfamily classification schemes for most often in exposed regions of the ribosomes. This the red algal family Corallinaceae are in general again is consistent with an intron origin through re- agreement with respect to the taxonomic value of cell verse-splicing. Remarkably, the distribution and phy- connection type (cell fusions versus secondary pit logenetic relationships of most group I introns in nu- connections), but differ over the relative weight given clear rDNA genes are also consistent with a reverse- to the character of genicular presence/absence. Con- splicing origin. These data underline the value of li- sequently, Corallinoideae, Melobesioideae and Metag- chens as a model system for understanding intron ori- oniolithoideae are recognized as distinct subfamilies. gin and stress the importance of RNA-level processes One scheme subsumes the geniculate Amphiroideae in the spread of these sequences in nuclear coding re- into the nongeniculate Lithophylloideae (based on gions. the common presence of secondary pit connections) and the nongeniculate Mastophoroideae into the geniculate Corallinoideae (based on the common presence of cell fusions); the other maintains these 19 subfamilies as four separate lineages. Small subunit INTRA-CELLULAR AND EXTRA-CELLULAR rRNA gene sequence data confirms the integrity of TOXINS IN THE RED TIDE DINOFLAGEL- Corallinoideae and Melobesioideae and fully supports a revised classification subsuming Amphiroideae into LATE, GYMNODINIUM BREVE Lithophylloideae. Surprisingly, Mastophoroideae Blum P. C., Henry M. S., Pierce R. H., Payne S. R., and Metagoniolithoideae (cell fusions) have a closer & Lyons, J. I. affinity to the emended Lithophylloideae (secondary Mote Marine Laboratory, 1600 Ken Thompson Park- pit connections) than with Corallinoideae (cell fu- way, Sarasota, FL 34236 USA sions). These preliminary results cast doubt on the value of using cell connections as a primal character. The marine dinoflagellate, Gymnodinium breve (Davis), From ultrastructural investigations of 28 coralli- produces several neurotoxins that cause neurotoxic noidean genera, including seven mastophoroidean shellfish poisoning (nsp), massive fish kills and respi- genera and two lithophylloidian genera, it appears ratory irritation in marine mammals and humans. that the presence/absence of an electron- dense ma- The common method for discerning toxic levels of G. terial (EDM) surrounding nuclei during sporogenesis breve for public health advisories is enumeration of is a more reliable indicator of subfamily affiliation live cells in a given water mass. In this study, labora- than cellular connections. Our findings support the tory cultures, as well as natural blooms, were added to revised classification of Lithophylloideae and suggests a stirred ultra-filtration cell concentrator to separate closer affinity to Lithophylloideae (secondary pit con- viable cells containing intra-cell toxins from ambient nections, no EDM) than to Corallinoideae (cell fu- water containing extra-cell toxins. Methods were vali- sions, EDM). However, EDM data indicates that Mas- dated using various mixtures of lysed and whole G. tophoroideae may be polyphyletic as three genera breve laboratory culture. Extractions and recovery of have EDM and four do not. brevetoxins were done using a C-18 bonded-phase glass fiber extraction disc eluted with methanol. Total PbTx toxin concentrations were quantified by HPLC/ UV using a C-18 column and an 85:15 methanol:water 21 (1 ml minϪ1) isocratic elution at 215 nm. This method PORPHYRA SUBORBICULATA, PORPHYRA CAR- of separation and extraction was subsequently applied OLINENSIS AND PORPHYRA LILLIPUTIANA - to water samples collected during natural blooms THREE NAMES FOR ONE SMALL PORPHYRA along two different areas of the Florida Gulf coast. Broom, J. E.1, Nelson, W. A.2, Jones, W. A.1, Yarish, The results indicated that early stages of G. breve 3 4 4 blooms contained primarily intra-cell toxins with extra- C. , Aguilar Rosas, R. , & Aguilar Rosas, L. E. 1 cell toxins increasing as the bloom progressed, even Department of Biochemistry, University of Otago, PO though very few viable G. breve cells were present. This Box 56, Dunedin, New Zealand; 2Museum of New suggests that enumeration of cells alone may be insuf- Zealand Te Papa Tongarewa, PO Box 467, Welling- ficient and additional toxin quantitation is necessary. ton, New Zealand; 3Department of Ecology and Evolu- 8 PSA ABSTRACTS tionary Biology, University of Connecticut, 1 Univer- have played key roles in our understanding of na- sity Place, Stamford, CT 06901 USA; 4Facultad de ture’s most abundant macromolecule. Ciencias Marinas, Universidad Autonoma de Baja California, Apartado Postal 453, Ensenada, Baja 23 Caliornia, México CHARACIOCHLORIS AND CHARACIOSIPHON FORM A SISTER GROUP TO THE The genus Porphyra is ancient, successful, and mor- “DUNALIELLA” LINEAGE phologically simple. Its members provide a particular challenge to systematists who must decide whether Buchheim, M. A. & Buchheim, J. A. shared features are a result of homoplasy, or reflect Department of Biological Science, The University of recent common ancestry. Three species of diminutive Tulsa, 600 South College Avenue, Tulsa, Ok 74104 Porphyra with widespread geographic origins share USA many common morphological features: P suborbiculata Kjellm. has been reported from the west Pacific and The freshwater green algal genera, Characiochloris and Indian Oceans, P. carolinensis Coll et J. Cox from the Characiosiphon, are distinctive taxa for which no clear west Atlantic, and P lilliputiana W. A. Nelson, G. consensus exists regarding phylogenetic placement. A.Knight et M. W. Hawkes from New Zealand. Com- Characiochloris is an epiphytic unicell that exhibits parison of 18S rDNA sequence data from small Por- multiple (Ͼ2), scattered contractile vacuoles through- phyra thalli from Mexico, Japan, New Zealand, Austra- out the cytoplasm of the vegetative cell. Although lia and Connecticut indicate that these three taxa in Characiochloris has been placed in the Tetrasporales by fact belong to one cosmopolitan species, which is dis- most systematists, the uncertain status of this green al- tributed over three oceans and two hemispheres. gal order raises questions regarding the position of Analysis of sequence data from introns present in the Characiochloris. Characiosiphon, a coenocytic freshwater 18S rDNA and from the ITS region suggest that this organism, has been linked to another freshwater co- distribution may be linked to human activity, and enocyte, Protosiphon. However, multiple chloroplasts, raises the question of to which geographic locality this greater thallus size, and a strictly aquatic life history entity is truly endemic? for Characiosiphon have led to comparisons with caul- erpalean ulvophytes. Phylogenetic analysis of 18S and 26S rDNA data was undertaken to test hypotheses of relationship for Characiochloris and Characiosiphon. Re- 22 sults from molecular phylogenetic analyses strongly ALGAE AS USEFUL TOOLS IN CELLULOSE support a sister relationship for Characiochloris and RESEARCH Characiosiphon. In addition, the Characiochloris/Charac- Brown, Jr., R. M. iosiphon clade is resolved as a sister group to the “Du- Section of Molecular Genetics and Microbiology, School naliella” lineage of the Chlamydomonadales that in- of Life Sciences, The University of Texas at Austin, cludes Ascochloris, Chlorogonium, Dunaliella, Haematococcus, Austin, TX 78712 USA Protosiphon and Spongiochloris. These results further support the hypothesis that the “Dunaliella” clade includes the majority of taxa that exhibit multiple con- This presentation will review the 1976 discovery of the tractile vacuoles. Moreover, these results support an enzyme complex in cellulose biosynthesis in Oocystis interpretation of the Characiosiphon coenocyte as a apiculata. A linear terminal complex (TC) was found modified zoosporangium. to be associated with a microfibril, and from other freeze fracture applications, TCs have been found in many different algal genera. In fact, the algae have 24 the most diverse and complex TCs among all organ- PSEUDOFILAMENTOUS GREEN ALGAE FORM isms. TC diversity in terms of the evolution of cellu- INDEPENDENT CHLOROPHYTE AND STREP- lose biogenesis will be discussed. Combining the latest TOPHYTE LINEAGES information from biochemistry and molecular genetics, the multiplicity of cellulose biogenesis will be re- Buchheim, M. A. & Buchheim, J. A. viewed. Cellulose molecular weight, crystalline struc- Department of Biological Science, The University of ture, and mode of glycosylation for polymer Tulsa, 600 South College Avenue, Tulsa, Ok 74104 formation all indicate that cellulose biogenesis is an USA extremely complex process. Major questions still remain, and the enzymes for cellulose biosynthesis have The pseudofilamentous condition in green algae has yet to be crystallized and their structure elucidated; been characterized as the formation of a linear array however, the wealth of new information on cellulose of autospores. Although it is likely that this character- structure and biosynthesis from algae to vascular ization will be found to be an over-simplification, it plants, including bacteria and tunicates, all point to a serves as a logical starting point for a study of diversity very exciting and useful area of research. The algae among pseudofilamentous taxa. Therefore, given that PSA ABSTRACTS 9 molecular phylogenetic analyses have revealed that (DON). In this study, benthic and planktonic species coccoid, autospore-formers are found in a number of of Prorocentrum were grown on L1 media with the sole independent green algal lineages, it is reasonable to N-source varying among treatments as nitrate, ammo- expect that pseudofilamentous taxa are likely to be nium, urea, L-glutamic acid, and high molecular found in a number of distinct lineages. In order to weight natural DON. An ELISA specific to the DSP test this hypothesis, data from the nuclear-encoded toxins, okadaic acid and 35-methylokadaic acid, was 18S r RNA gene were collected from several pseudofil- used to determine toxin production by each species amentous, green algal genera (Geminella, Gloeotila, when grown on the different N sources. Preliminary Hazenia, Interfilum, Microspora, and Sphaeroplea) and in- results indicate that some organic forms of N support corporated into an 18S rRNA database of chlorobiont growth as well as inorganic forms for Prorocentrum min- taxa. Results from phylogenetic analyses of these data imum, P. mexicanum, and P. hoffmannianum. support (1) an alliance of Interfilum, two Geminella isolates, and Klebsormidium within the streptophyte lineage, (2) an alliance of two Geminella isolates and 26 Microspora as a sister group to the ulvophycean/chlo- CULTIVATION STUDIES OF GIGARTINA rophycean/trebouxiophycean clade or as a sister SKOTTSBERGII IN SOUTHERN CHILE group to trebouxiophycean taxa, (3) an alliance of Buschmann, A. H.1, Correa, J. A.2 & Wester- Hazenia with ulotrichalean taxa, (4) of Gloeotila with meier, R. 3 trebouxiophycean taxa and (5) an alliance of Sphaero- 1Dep. Acuicultura, Universidad de Los Lagos, Casilla plea with chlorophycean taxa. These data confirm that 2 the filamentous condition has evolved in a number 933, Osorno, Chile; Dept. Ecolog’a, P. Universidad 3 of independent lineages. Moreover, these data fur- Catlica de Chile, Santiago, Chile; Universidad Aus- ther illustrate that the extent of molecular varia- tral de Chile, Puerto Montt, Chile bility within the green algae is far from fully appreciated. In Chile, the demand for carrageenophytic algae has increased significantly in recent years. The preferred 25 species is Gigartina skottsbergii, with landings of 26,181 tons in 1998. To avoid a possible overexploitation the THE EFFECT OF NITROGEN SOURCE ON development of cultivation technologies is needed. In THE GROWTH AND TOXICITY OF THREE this study we present a critical view of published and POTENTIALLY HARMFUL DINOFLAGEL- new information to propose the best culture strategy LATES for this species. The results indicate that viable spores Burns, C. L.1,2, Pennock, J. R. 1,2,3, Lores, E. M.4, are seasonally available only during winter, with tet- & Greene, R. M.4 raspore germination rates of ca. 40%. Germination of 1Dauphin Island Sea Laboratory, 101 Bienville Blvd, carpospospores is lower than 20%. Growth in tanks Ϫ1 Dauphin Island, AL 36528 USA; 2University of South can be as high as 1% day and high nutrient concen- Alabama, Department of Marine Sciences, Mobile AL trations (N and P) must be added. Gigartina also present a high and unique regeneration capacity. USA; 3University of Alabama, Department of Biologi- 4 Field experiments indicate that Gigartina can be cul- cal Sciences, Tuscaloosa, AL USA; U. S. Environmen- tured in rope systems, where the inoculum can be tis- tal Protection Agency, Gulf Ecology Division, Gulf sue fragments. These results indicate that vegetative Breeze, FL USA 32561 propagation techniques can be used for the massive culture of Gigartina, but selection of a high growing Increases in population and agriculture in coastal ar- strain remains as one of the future challenges. eas can result in increased nutrient inputs and alterations in the ratios of organic to inorganic nutrients in coastal waters. Such changes in coastal nutrient re- 27 gimes can affect phytoplankton community structure MONITORING THE PERSISTENCE OF by creating conditions favorable for growth and domi- GIANT KELP AROUND SANTA CATALINA nance of algae that were not dominant before. The ef- ISLAND USING A GEOGRAPHIC INFORMA- fect that changes in ratios and concentrations of nu- TION SYSTEM trients have on toxicity of harmful algal species is not well known. There seems to be a relationship; how- Bushing, W. W. ever, between nutrient stress and toxin production Science, Education and Ecological Restoration, Santa among harmful phytoplankton producing low-N tox- Catalina Island Conservancy, P. O. Box 2739, Ava- ins, e.g. Diarrhetic Shellfish Poisoning (DSP) toxins. lon, CA 90704 USA Even less is known about the relationship between organic nutrient uptake and toxin production. Benthic Geographic information systems (GIS) facilitate mon- species and species in coastal areas are probably ex- itoring and analysis of population distributions at spa- posed to greater fluxes of dissolved organic nitrogen tial and temporal scales differing from those em- 10 PSA ABSTRACTS ployed in conventional field monitoring. This study 29 utilizes a GIS-based gap analysis of a network of ma- EFFECT OF LIGHT QUALITY ON POLYSAC- rine reserves around Santa Catalina Island relative to CHARIDE YIELD AND COMPOSITION OF the regional ecology, disturbance regime, and persis- TWO RED ALGAE tence of giant kelp (Macrocystis pyrifera), a keystone 1 2 3 species in the nearshore, marine environment. Cat- Carmona, R. , Vergara, J. J. , Lahaye, M. & Niell, 4 alina’s orientation and greatly-dissected coastline cre- F. X. ate diverse microhabitats with respect to storm expo- 1Department of Ecology and Evolutionary Biology, Uni- sure, temperature, light regime and topographic versity of Connecticut, One University Place, Stamford, factors. GIS overlay methods applied to multi-tempo- CT 06901-2315, USA; 2Department of Ecology, Uni- ral kelp distribution maps generated a model repre- versity of Cadiz, Poligono Rio San Pedro, 11510 Pu- senting the spatial “persistence” of kelp. Correlations erto Real, Cadiz, Spain; 3Institut National de la Re- between the kelp’s geographic distribution and persis- cherche Agronomique, Unite de Recherche sur les tence, the disturbance regime and physical variables Polysaccharides, leurs Organisations et Interactions, conferring resistance to or recovery from it were BP 71627, 44316 Nantes, France; 4Department of drawn. This analysis identified regions of persistent Ecology, University of Malaga, Campus de Teatinos, kelp under disturbance regimes markedly different from those in the existing reserves, suggesting the des- Malaga 20971, Spain ignation of additional reserves in unprotected areas is ecologically warranted. Two species of agarophytes, Gelidium sesquipedale (Clem.) Born. et Thur. and Gracilaria tenuistipitata var. liui (Zhang & Xia), have been cultured in chemostat systems under different light qualities to study the response of growth and polysaccharide yield and composition to certain wavelengths. The yield of galac- 28 tans, methoxyl groups and sulphate content in the EFFECT OF TEMPERATURE AND DESICCA- agar as well as the starch concentration of these spe- TION ON THE PHOTOSYNTHETIC PERFOR- cies are controlled by light quality in a different way, MANCE OF PORPHYRA PERFORATA presumably because of their patterns of growth. The polysaccharide characteristics will be discussed in rela- Cabello-Pasini, A., Diaz-Martín, M. A., Muñiz- tion to the growth and metabolism of those algae. Salazar, R., Zertuche-Gonzalez, J. A., & Pacheco- Ruiz, I. 30 Instituto de Investigaciones Oceanológicas, Univer- sidad Autónoma de Baja California, A.P. 453, DO PHYSICAL FACTORS REGULATE PHY- Ensenada, Baja California 22800 Mexico TOPLANKTON DISTRIBUTION PATTERNS IN LARGE, SHALLOW LAKES? Porphyra perforata is a common seaweed inhabiting the Carrick, H. J. upper intertidal zone, and as a consequence it experi- Watershed Research & Planning Department, South ences great fluctuations in tissue temperature and Florida Water Management District, West Palm Beach, desiccation. The objective of this work was to evaluate FL 33406 USA the effect of ambient temperature and the tissue desiccation status on the photosynthetic performance of Factors that regulate phytoplankton dynamics in shal- P. perforata. Photosynthetic performance was evalu- low, productive lakes are poorly understood, due to ated polarographically after the temperature or desic- their predisposition for frequent algal blooms and cation treatments. Maximum photosynthesis (Pmax) sediment resuspension events. In Lake Apopka, great- occurred between 25 and 30Њ C and decreased at est phytoplankton biomass reflects wind-induced re- higher and lower temperatures, however, no signifi- suspension of algae (meroplankton) that exists on the cant differences were observed in the initial slope of aphotic lake bottom in a layer approximately 5 cm photosynthesis (␣) from 10 to 30Њ C. This suggests thick; this assemblage is dominated by diatoms (Ͼ60% that the photosynthetic efficiency of this species does of total biomass) that can occur in resting stages. not decrease as a result of fluctuating temperatures Once exposed to moderate light, meroplankton are during tidal emergence/submergence. Pmax and ␣ capable of growth and photosynthetic rates compara- were relatively constant in tissue of P. perforata with 5 ble with surface populations. In Lake Okeechobee, re- to 100% relative water content. This also suggests that mote sensing was used to assess the basin-wide distri- natural desiccation rates during low tides do not de- bution of suspended particles. Satellite reflectance crease photosynthetic rates in this species. Variations values agreed well with in situ particle densities at 20 in the synthesis of specific proteins as a result of fluc- in-lake stations (average r2; LANDSAT ϭ 0.81, tuations in temperature and relative water content in AVHRR ϭ 0.53), and maps of algal blooms (r2 ϭ 0.79, the tissue of P. perforata are being studied. p Յ 0.01). The greatest chlorophyll concentrations PSA ABSTRACTS 11 occurred in the vicinity of tributary nutrient inputs at of this clade with other groups was uncertain due to the lake’s perimeter, while turbidity increased towards lack of bootstrap support. Oscillatoria sp. (UTCC393) the center of the lake reflecting predominant water was closely related to the previously sequenced Oscilla- circulation patterns. These results underscore the im- toria limnetica and likewise, Phormidium molle portance of physical-biological interactions in lakes. (UTCC77) and Phormidium tenue (UTCC473) were placed in a well supported clade with other Oscillato- 31 riales. The other four taxa were variously placed in FRESHWATER DINOFLAGELLATES OF BEL- the trees and their phylogenetic positions could not IZE, C.A. be determined with certainty. Carty, S. Department of Biology, Heidelberg College, Tiffin, OH 33 44883 USA ULTRASTRUCTURE AND CYTOCHEMIS- TRY OF SPERMATANGIAL DEVELOPMENT Freshwater dinoflagellates have not previously been AND FERTILIZATION IN AGLAOTHAMNION reported from Belize, although there has been exten- OOSUMIENSE (CERAMIACEAE, RHODO- sive work with marine dinoflagellates and some work PHYTA) with other freshwater groups. Freshwater dinoflagel- Chah, O. K.1, Lee, I. K.1 & Kim, G. H.2 lates are more frequently observed in standing water 1Department of Biology, Seoul National University, Seoul, and none have been observed in the several streams 151-732, Korea; 2Department of Biology, Kongju Na- and rivers sampled since 1990. The goal in 1998 was to examine water samples from small ponds within tional University, Kongjushi, Chungnam 314-701, Korea hours of collection to improve the chance of observing swimming dinoflagellates. A plankton net was Spermatial development and fertilization processes used and whole water samples also were collected. A were investigated by electron microscopy in Ag- small brown water pond on a peninsula and 30m from laothamnion oosumiense Itono. The spermatium is com- the Caribbean yielded a bloom of Thompsodinium inter- posed of two parts, an ovoidal head and two append- medium. Dinoflagellates, including Peridinium centenni- ages projecting from each distal end. The appendages ale, Katodinium sp., and Peridinium sp. in the Um- originate from spermatangial vesicles (SVs) and fol- bonatum Group, were observed within “Crocodile low a developmental sequence beginning as amor- pond” and “Lily pond” on the mainland. phous material and ending as a fully-formed fibrous structure compressed within the SVs. SV formation is 32 due to contributions initially from endoplasmic reticulum and later from dictyosome-derived vesicles. SOME PHYLOGENETIC RELATIONSHIPS Chemical differentiation of the spermatial wall occurs WITHIN THE OSCILLATORIALES (CYANO- early in its development. Calcofluor white does not la- BACTERIA) CLADE USING 16S RDNA GENE bel spermatial walls, indicating an absence of cellu- SEQUENCE DATA lose polysaccharides, which are abundant in vegeta- Casamatta, D. A. & Vis, M. L. tive cell walls. Liberated spermatia had a prophase Department of Environmental & Plant Biology, Ohio arrested nucleus with a pair of polar rings. The cyto- University, Athens, OH 45701 USA plasm of the trichogyne was connected with that of spermatia at the fertilization canal. The cytoplasm of An approximately 1400 base pair region of the 16S the trichogyne was empty when the nuclear fusion be- rDNA gene was sequenced from taxa within the Oscil- tween spermatium and carpogonium occurred. latoriales in order to assess phylogenetic relationships. Ten previously unsequenced strains were obtained 34 from the University of Toronto Culture Collection. COMPARISON OF GROWTH AND REPRO- New sequence data were combined with previously DUCTION BETWEEN TWO POPULATIONS published sequences from a wide representation of cyanobacteria including all currently available, com- OF SARGASSUM SILIQUASTRUM IN PING plete Oscillatorialian taxa. Trees constructed using CHAU, HONG KONG parsimony, distance, and maximum likelihood meth- Chan, W. Y. & Ang, P. O. ods were similar in topology, although a few taxa were Department of Biology, The Chinese University of Hong variable in their placement depending on the phylo- Kong, Shatin, N.T., Hong Kong SAR, China genetic method employed. Newly sequenced taxa of the genera Phormidium, Oscillatoria, and Lyngbya did In Ping Chau Island of Hong Kong, two populations not form monophyletic clades based on traditional of Sargassum siliquastrum are present. One is in the generic designations. Two Lyngbya strains (UTCC296 shallow water of about 1 to 3 m Chart Datum (CD), and 313) and Phormidium subfuscum (UTCC474) formed and the other one in deeper water of 5 to 10 m CD. a well supported monophyletic clade, but the affinity These two populations are separated by an extensive 12 PSA ABSTRACTS sand patch. Individuals of the “shallow” water popula- of this alga. We are using the AFLP plant mapping tion increased their size from a mean length of 8.3 Ϯ protocol by PE Applied Biosystems to detect genetic 3.6 (SD) cm in Aug 1998 to a maximum of 48.2 Ϯ variability in the three isolates of C. virescens. AFLP is a 29.9 cm in early Jan 1999 before they started to die PCR-based DNA fingerprinting technique that detects back. In the following year, they attained a minimum the presence or absence of restriction fragments of 6.1 Ϯ 3.8 cm in May 1999 and a maximum of 56.1 Ϯ rather than fragment length differences. Because the 23.6 cm in Dec 1999. Their reproductive period lasted number of restriction fragments that can be detected for two to three months from Jan to Feb 1999, and with the AFLP technique is “virtually unlimited,” it is a again from Nov 1999 to Jan 2000. The “deep” water very powerful tool for assessing the degree of related- individuals increased their size to a maximum of 123 Ϯ ness or variability among cultivars or isolates. AFLP 50.8 cm at the end of Jan 1999 and started to die back techniques have been used successfully to distinguish in Feb, 1999. They again reached their maximum morphologically identical bacteria, determine relat- mean length in Jan 2000. Their reproductive period edness among soybean accessions, reveal genetic vari- lasted for five to six months from Sept 1998 to Feb ability within bee samples, and identifyfall armyworm 1999 and again from Sept 1999 to Jan 2000. The strains and hybrids. “deep” water individuals tended to be longer in size and they attained their maximum growth a month 36 later than the “shallow” water individuals. Their re- COLD ACCLIMATION OF TWO STRAINS OF productive season tended to start earlier and lasted THE CYANOBACTERIUM, SPIRULINA PLAT- longer than those in the “shallow” water. These differ- ENSIS ences in the phenology of the two populations may be related to the temperature differences (up to 5Њ C dif- Chien, L.-F. & Vonshak, A. ference in summer) between the two depths. Sargas- Microalgal Biotechnology Laboratory, The Jacob sum siliquastrum is likely to be a cold adapted species Blaustein Institute for Desert Research, Ben-Gurion such that warmer temperature in the shallow water University of Negev, Sede-Boker Campus, 84990, Israel has compressed and shortened their rapid growth and reproductive period to within the few colder The changes in the antioxidant enzymes and photo- months in fall and winter. synthetic activities during cold acclimation in two strains of the cyanobacterium, Spirulina platensis, marked as Kenya and M2, were investigated. Cells 35 were cultured at 33Њ C then transferred to either 20Њ C SEXUAL REPRODUCTION AND GENETIC or 15Њ C. Growth rate of both strains ceased when the VARIATION IN THE SUBAERIAL ALGA temperature shifted from 33 to 20Њ C and resumed to CEPHALEUROS VIRESCENS (ULVOPHYCEAE, a slower rate after the first 24 h. Similarly when the CHLOROPHYTA) temperature was shifted from 33 to 15Њ C, a complete Chapman, R. L.1, Waters, D. A.1, & Lopez- cessation of growth took place but this time the Bautista, J. M.2 growth resumed only after 5 to 6 days. The activities of 1 ascorbate perooxidaseperoxides were immediately de- Department of Biological Sciences, Louisiana State creased to about 40–60% in Kenya and 20–40% in M2 2 University, Baton Rouge, LA 70803 USA; Department when the temperature was shifted to 20 or 15Њ C and of Biology, University of Louisiana at Lafayette, Lafay- remained about the same level during further cold ette, LA 70504 USA cultivation. The activity of glutathione reductase was not modified immediately after the transfer to 20 or Cephaleuros virescens is a pantropical subaerial green 15Њ C; however, it trended to increase gradually in M2 alga with no known long-range dispersal mechanisms. during cultivation at 15Њ C. The changes in the maxi- Sexual reproduction is relatively rare and may involve mal efficiency of PSII photochemistry (Fv/Fm) were intragametangial fusion of identical, mitotically pro- followed in order to study the effect of low tempera- duced gametes. This situation may be a consequence ture acclimation on the photosynthetic apparatus of of adaptation to the subaerial habitat. Genetic varia- the two strains. tion among populations of C. virescens may be very low and might be positively correlated to the distance 37 (hence, time) separating populations. Thus, assessing ATLANTIC KELP SPECIES LAMINARIA LONGI- the global biogeography of C. virescens requires analy- CRURIS AND L. SACCHARINA (LAMINARI- sis of what might be low levels of variation. Because C. ALES) ARE CONSPECIFIC virescens occurs on literally hundreds of different host 1 1 1 2 species, the question of host-races must also be consid- Cho, G. Y. , Yoon, H. S. , Boo, S. M. , & Yarish, C. 1 ered. Preliminary analysis of local populations of C. vire- Department of Biology, Chungnam National Univer- scens, originally obtained as field collections from three sity, Daejon, 305-764, Korea; 2Department of Ecology different host species and subsequently raised in cul- and Evolutionary Biology, University of Connecticut, ture, is the first step in addressing the biogeography Stamford, CT 06903 USA PSA ABSTRACTS 13

The identification of two Atlantic kelp species, Lami- E2L 4L5, Canada; 2University of New Brunswicc, naria longicruris and L. saccharina, has been controver- Electron Microscopy Unit, Bag Service 45111, Frederic- sial. In order to know if these two species are conspe- ton, NB, E3B 6E1, Canada cific, plastid-encoded RuBisCo spacer and nuclear rDNA ITS sequences were analyzed from twelve indi- Variations of the different phosphorylated fractions in viduals of L. longicruris, five of L. saccharina, from Con- tissues of starved and fresh plants of Porphyra purpurea, necticut and Nova Scotia. Four individuals of L. digi- a representative of the Bangiophyceae, over a 72 hour tata from the above coasts were also analyzed as incubation period in pulse-enriched seawater (15 ␮M reference in this study. All RuBisCo spacer sequences phosphorus and 25 ␮M nitrogen) were analyzed and from L. longicruris and L. saccharina were exactly iden- compared to those in Chondrus crispus, a representa- tical except for one individual with three different nu- tive of the Florideophyceae, considered the more ad- cleotides. Zero to five different nucleotides of ITS se- vanced of the two classes of the Rhodophyta. Differ- quences, inculding four polymorphic sites, were ences point towards P. purpurea being a much more found in two species. However, their RuBisCo spacer metabolically active phosphorus “pump” than C. cris- and ITS sequences are quite different from those of L. pus, with a higher phosphorus turnover rate, in which digitata. These results strongly suggest that L. saccha- the orthophosphate fraction is predominant and acid- rina (L.) Lamour. 1813 is conspecific with L. longicru- soluble and acid-insoluble polyphosphates are not as ris De La Pylaie 1824 and the different local popula- significant storage pools. Confirmation of the pres- tions, despite various morphotypes, may be genetically ence of acid-insoluble polyphosphates, detected by very similar. chemical analyses, in the form of cytoplasmic granules was obtained by transmission electron microscopy and energy dispersive X-ray microanalysis. The gran- 38 ules in P. purpurea were, however, much smaller (20 to TAXONOMY OF CERAMIUM (CERAMI- 110 nm in diameter) than those in C. crispus (around ACEAE, RHODOPHYTA) FROM OREGON 1 ␮m, but some larger than 2 ␮m in diameter). Cho, T. O.1, Boo, S. M.1, & Hansen, G.2 Larger granules (290 to 310 nm in diameter) were 1Department of Biology, Chungnam National Univer- also observed. Their surface was more uniformly elec- sity, Daejon 305-764, Korea; 2Hatfield Marine Science tron-opaque without the reticulated or globular ap- Center, Oregon State University, Oregon, U S A. pearance of typical polyphosphate granules. Energy dispersive X-ray microanalysis demonstrated that they were siliceous granules. To our knowledge, this is the During a recent survey of marine red algae in Ore- first report in algae of such structures whose occur- gon, U. S. A., 6 of the 7 species of Ceramium reported rence and metabolic role remain enigmatic. from this state were collected in the intertidal zone. These included Ceramium californicum J. Agardh, C. cimbricum H. Petersen in Rosenvinge, C. codicola J. Agardh, C. gardneri Kylin, C. kondoi Yendo, and C. paci- 40 ficum (Collins) Kylin. Detailed descriptions and illus- MOLECULAR AND GENETIC ANALYSIS OF A trations of vegetative and reproductive development RETROGRADE SIGNALING PATHWAY FROM in C. californicum, C. codicola, and C. pacificum are pre- THE PLASTID TO THE NUCLEUS sented for the first time in this paper. Descriptions are Chory, J.1, Larkin, R. 1, Surpin, M.1; Mochizuki, also given for C. cimbricum and C. kondoi, species previ- N.2, & Brusslan, J.3 ously only reported from elsewhere in the northwest- 1Howard Hughes Medical Institute & The Salk Insti- ern Pacific. These latter species were common on tute for Biological Studies, La Jolla, CA 92037 USA; floating docks, sites where introduced species fre- 2 quently occur. Ceramium eatonianum and C. washing- Kyoto University, Kyoto, 606-8502 JAPAN; 3 toniensis, the other 2 species known from Oregon, California State University, Long Beach, CA 90840 were found to belong to other genera or were not col- USA lected during this study. Chloroplast development requires coordinate nuclear and chloroplast gene expression. A putative signal from 39 the chloroplast couples the transcription of certain POLYPHOSPHATE AND SILICEOUS GRAN- nuclear genes encoding photosynthesis-related proteins with chloroplast function. We have identified ULES IN THE GAMETOPHYTES OF THE RED five Arabidopsis nuclear genes (GUN1-GUN5) necessary ALGA PORPHYRA PURPUREA (BANGIO- for coupling the expression of some nuclear genes to PHYCEAE) the functional state of the chloroplast. Homozygous Chopin, T.1, Morais, T.1, Belyea, E.1, & Belfry, S.2 recessive gun mutations allow nuclear gene expres- 1University of New Brunswick, Centre for Coastal Stud- sion in the absence of chloroplast development. ies and Aquaculture, P.O. Box 5050, Saint John, NB, GUN1 mutants have no visible phenotype in white 14 PSA ABSTRACTS light, but GUN1 mutations interfere with the switch 42 from heterotrophic to photosynthetic growth in young PHYLOGENETIC RELATIONSHIP OF COLEO- seedlings. GUN2-5 are pale. Double mutant studies CHAETE AND CHAETO-SPHAERIDIUM (COLEO- suggest that gun1 affects a separate pathway from CHAETALES) BASED ON THE CHLOROPLAST GUN2, 3, 4, and 5. GUN2 and GUN3 are allelic to the known photomorphogenetic mutants, hy1 and hy2, GENES RBCL AND ATPB involved in phytochromobilin biosynthesis down- Cimino, M. T., Karol, K. G., Lewandowski, J. D., stream from heme. GUN5 encodes the ChlH subunit & Delwiche, C. F. of Mg-chelatase, and GUN4 encodes a novel chloro- Department of Cell Biology and Molecular Genetics, plast protein that is essential for chlorophyll accumu- University of Maryland - College Park, College Park, lation. GUN4 does not appear to be required for the MD 20742 USA synthesis of protochlorophyllide from 5-aminole- vulinic acid, which suggests that GUN4 might be re- The freshwater green algal genera Coleochaete and Cha- quired for the early steps and/or the late steps of etosphaeridium form the order Coleochaetales sensu chlorophyll synthesis or another process that is re- Mattox and Stewart (Charophyceae). To test the quired for chlorophyll accumulation. Our data sug- monophyly of this order, a data set was compiled con- gest that certain perturbations of the tetrapyrrole bio- sisting of the chloroplast genes rbcL and atpB from synthetic pathway generate a signal from chloroplasts nine species of Coleochaete, six strains of Chaetosphaerid- that causes transcriptional repression of nuclear ium, and other representative green algae and em- genes encoding plastid-localized proteins. The pre- bryophytes. Phylogenetic analyses of these data indi- cise nature of this signal and the mechanism by which cate that Coleochaete and Chaetosphaeridium form a this signal is transduced to the nucleus is under inves- monophyletic group that diverged late in basal strep- tigation. tophyte evolution. By contrast, published analyses of nuclear encoded small subunit ribosomal DNA (rDNA) data for similar taxa do not support a mono- 41 phyletic Coleochaetales. These analyses suggest Cha- BUILDING A SPECIES PHYLOGENY FOR etosphaeridium is an early branching lineage within THE GENUS COLEOCHAETE (COLEOCHA- Streptophyta and/or that Chaetosphaeridium forms a ETALES) USING THE GENES RBCL AND ATPB lineage with the unicellular flagellate Mesostigma (Me- Cimino, M. T. & Delwiche, C. F. sostigmatophyceae). A close relationship of Chaeto- Department of Cell Biology and Molecular Genetics, sphaeridium and Mesostigma is not supported by the University of Maryland - College Park, College Park, rbcL and atpB data. Reexamination of morphological characters suggests a monophyletic Coleochaetales is MD 20742 USA supported by several characters that include branching filamentous habit, unicellular apical growth, The freshwater green alga Coleochaete Breb. (Co- sheathed hairs, and rotating plastids. leochaetaceae; Coleochaetales) is a key streptophyte genus and is important to the understanding of the evolutionary origin of embryophytes (land plants). To date only a few species have been available from pub- 43 lic culture collections. To facilitate research on this HABITAT HETEROGENITY ON TROPICAL genus we have isolated 17 previously uncultured spe- ROCKY SHORES: A SEAWEED STUDY IN cies of Coloechaete from material collected in the SOUTHERN BRAZIL United States, Puerto Rico, and the Dominican Re- Coimbra, C. S.1,2 & Berchez, F. A. S.2 public. Sequences for the genes rbcL and atpB were 1Departament of Biological Sciences, Universidade Es- determined for these new isolates of Coleochaete (and for existing cultures) and combined with sequences tadual de Santa Cruz, Rod. Ilhéus/Itabuna, Km. 16, 2 from representative other streptophytes. Phylogenetic Bahia, Brazil; Departament of Botany, Biosciences In- analyses indicate that Coleochaete, along with Chaeto- stitute, Universidade de São Paulo, Caixa Postal sphaeridium and Chara, are closely related to embryo- 11461 SP-Brazil phytes and constitute a ‘higher streptophyte’ clade. At least four well-supported lineages exist within Co- The main concepts in coastal community ecology leochaete. Characteristic growth forms have been iden- have been proposed to explain relatively plain sub- tified for these four lineages, with important charac- strate, specially at temperate zones. We show that, on ters including aspects of thallus establishment, thallus a irregular tropical substratum (a complex system of habit, zygote development and hair sheath position. quarry stones with diverse shapes and sizes), the classi- These data provide an improved understanding of cal community zonation scheme is only applicable if species diversity and character evolution in the genus we simplify the tridimensional substrate arrangement Coleochaete, and facilitate examination of hypotheses to a single dimensioned universe: the topographic concerning character evolution in the streptophytes. level. Thus, the continuous spatial distribution implic- PSA ABSTRACTS 15 ited in “zones” notions is nonexistent. Our study was Forty years ago, after 1 1/2 years of weekly surveys, a conducted on a rocky shore at Ubatuba (São Paulo Baltimore fishpond was inoculated with three identifi- State, Brazil) during one year. Percentual coverage able clones of Pandorina morum. The results of subse- was estimated using the quadrat method located by quent recollection attempts are published in Amer. random coordinates. The topographic level was deter- Naturalist 118:761 (1981). More recently, molecular mined for each sampling element. Analysis of spatial analyses have permitted characterization of the P. splitting revealed large-scale stratification of the shore morum population that was endemic to the pond. The into dominiums related to topographical level: 1) Up- results, and their comparison with those from other P. per Dominium (represented by Chthamalus sp. and morum sites, challenge some longstanding assump- Tetraclita spalactifera); 2) Transition Level (composed tions concerning the importance of various lifehistory of Gymnogongrus griffithsiae, Gelidium aff. pusillum and stages to the introduction and maintenance of algal often Centroceras clavulatum);. and 3) Lower Domin- populations in temperate freshwater locales. ium (mainly Sargassum vulgare and occasionally Padina gymnospora, Dictyopteris delicatula and Grateloupia doryphora). These dominiums cannot be recognized as “bands” or continuous “zones” in a landscape view of the community. Otherwise, these bands could be observed on a small scale on each large quarry stone. 46 INFECTIOUS DISEASES IN MACRO-ALGAE: 44 THE EFFECT ON HOST FITNESS TUBE SIZE COMPARISON AND AUTO- Correa, J. A., Faugeron, S., Martínez, E., MATED GROWTH MEASUREMENT IN A Nimptsch, J. & Paredes, A. TUBULAR REACTOR USING SPIRULINA Departamento de Ecología, Facultad de Ciencias Bio- PLANTENSIS lógicas, P. Universidad Católica de Chile, Casilla 114- Coin, M. A., Bagherpour, S. & Gellenbeck, K. W. D, Santiago, Chile Rehnborg Center for Nutrition & Wellness, Nutrilite Division of Amway Corporation, 19600 6th Street, The understanding of infectious diseases of algae has Lakeview, CA 92567 USA improved significantly in recent years, particularly in the area of recognition and signaling, key processes A tubular photobioreactor for outdoor cultivation of that determine the success or failure of host invasion Spirulina platensis was successfully operated for the last by the pathogen. Ecological studies have also contrib- two years. The reactor was made of transparent 2.4-cm uted to better understanding the role of diseases in diameter tubes with a total length of approximately wild stands of the affected hosts. An aspect that has re- 101-m and a volume of 124-liter. Flow was induced us- ceived only limited attention is the effect of the infec- ing an airlift pumping system. To optimize the system tions on host fitness, and in this context, we report a further, a larger tube diameter was also tested. Prelim- first attempt to quantifying the effects of Pleurocapsa inary results have suggested that a larger tube diame- sp. (Cyanophyta) on the reproductive potential of its ter might provide increased output with reduced host Mazzaella laminarioides (Rhodophyta). Infections surface area requirements. Results of experiments by Pleurocapsa trigger the development of tumors that comparing the productivity of the same culture vol- can result in major changes in frond morphology and ume in tubes of 2.4 cm and 5.0 cm will be presented texture. Two populations of the host were considered which show a small decrease in productivity by vol- in the study. Our results indicate that infections do ume, but a large increase in areal productivity. This not cause a significant effect on the density or quality suggests that the larger tube diameter would be an ap- of the reproductive structures (i.e. cystocarps and tet- propriate choice for larger scale systems. Additionally, rasporangia). However, the number of spores, settle- data will be presented demonstrating the effectiveness ment rates, germination success and offspring sur- of an on-line surface scatter turbidimeter for accurate vival, were all affected negatively by the endophytic measurement of Spirulina density when correlated to infections. The reported information and field-col- manual dry weight measurements. lected data, strengthen the notion that pathogens of algae may exert strong effects on their hosts at several levels, including reproduction. These effects can vary 45 from host death during infections by highly patho- genic organisms to more subtle effects like those ob- THE FISH POND EXPERIMENT: CHAPTER served in the studied pathosystem. Infections by less TWO aggressive pathogens, however, still may determine Coleman, A. W. important effects at the population level by inducing BioMed, Brown University, Providence, RI 02912 differential mortality and reproductive success in in- USA fected individuals. 16 PSA ABSTRACTS

47 cies from shallow (2 to 3 m) water. Compared to shal- THE IMPACT OF DIFFERENTIAL GRAZING low water algae, those from 27 to 30 m were more sus- BY PHAGOTROPHIC CILIATES ON PHY- ceptible to photoinhibition, produced more reactive TOPLANKTON BIOMASS AND COMMUNITY oxygen (as measured by dichlorofluorescein production) and suffered lipid peroxidation when exposed STRUCTURE to surface solar radiation. These data could not be ex- Cowlishaw, R. J. plained by differences in activities of reactive oxygen Oregon Institute of Marine Biology, University of Ore- processing enzymes. Although activities of ascorbate gon, Charleston, OR 97420 USA peroxidase (APX) were higher in shallow water algae, the opposite was true for superoxide dismutase (SOD) There is a growing understanding that phagotrophic and catalase. In situ reactive oxygen production in ciliates are often important members of aquatic com- shallow water D. dichotoma varied over the course of munities in terms of their trophic role and mobiliza- the day on both a sunny and overcast day, and was tion of small cell production to higher consumers. As proportional to incident light and photosynthetic formidable consumers of small phytoplankton species electron turnover rate (ETR) determined with a sub- they are likely to be also important in determining the mersible modulated fluorometer. The natural popula- community composition of the pico- and nanophy- tion did not appear to experience lipid peroxidation. toplankton assemblages. Dilution method experi- Activities of SOD and APX remained constant over ments were conducted during the winter and summer the light period, whereas catalase declined in the af- in the South Slough, an arm of the Coos Bay on the ternoon on the sunny day, but not on the overcast southern Oregon coast, to assess the impact of ciliate day. Overall, our data demonstrate that algae produce grazing on two size fractions of chlorophyll (0.2 to 5 reactive oxygen in nature under non-stressed condi- mm and Ͼ5 mm) and on the growth and abundance tions and moderate light (Ͻ 300 mmole photons mϪ2 of specific phytoplankton groups, particularly crypto- sϪ1) and that this occurs independently of the activity phytes and Synechococcus sp. The premise of the dilu- of catalase. tion technique is that grazers are diluted with their food and the observed rate of change in chlorophyll or phytoplankton abundance is linearly related to the dilution factor. Results from previous studies using the dilution technique have been given in terms of the grazing impact of microzooplankton on total 49 chlorophyll. The findings of the research presented KELP ECOLOGY AND THE POINT LOMA using a more rigorous application of the dilution KELP FOREST: A BLEND OF THE OLD AND method suggest that ciliates are differential in their grazing of phytoplankton, targeting small phytoplank- THE NEW ton biomass and preying selectively on components of Dayton, P. K. & Tegner, M. J. the assemblage that constitute this biomass. Mail Code 0227, Scripps Institution of Oceanography, La Jolla, CA 92093 USA

The history of the Point Loma kelp forest parallels that of the earlier pioneers in Europe, with an early 48 descriptive focus moving quickly toward mechanistic REACTIVE OXYGEN METABOLISM IN THE studies. At Point Loma, research was initiated because TROPICAL BROWN ALGA DICTYOTA of large-scale loss of kelps, so from the beginning DICHOTOMA there was an urgency to restore the kelp forest with a Davison, I. R.1, Collén, J.2 & Fegley, J. C.1 concomitant focus on sea urchin grazing. We review 1 the evolving relationships between new questions and School of Marine Sciences and Department of Biologi- long-term observations that emphasize both small and cal Sciences, University of Maine, Orono, ME 04469 large-scale events in time and space. For example, the USA; 2Department of Physiological Botany, Uppsala early descriptive work grew into small-scale experi- University, Villavägen 6, S-752 36 Sweden mental work that demonstrated problems of scaling up from experiments. As we repeated experiments We studied reactive oxygen metabolism in natural over larger spatial and temporal scales we learned that populations of the brown alga Dictyota dichotoma grow- the low frequency variation at both scales is extremely ing on coral reefs on the west coast of Barbados in important and must be understood before small-scale March 2000. Algae from deep water (27 to 30 m) had results are generalized. Regime shifts in the physical Ϫ2 lower dark respiration (0.08 cf. 0.21 mmole O2 cm environment and the increasing effects of fishing rep- hϪ1), light compensation point (7 cf. 18 mmole pho- resent continuing challenges to the kelp community tons mϪ2 sϪ1) and gross light-saturated photosynthesis structure that make it critically important to consider Ϫ2 Ϫ1 (0.44 cf. 0.68 mmole O2 cm h ) than the same spe- scaling problems. PSA ABSTRACTS 17

50 malinized rabbit and human A, O, B erythrocytes. Ag- GROWTH AND ULTRASTRUCTURAL CHAN- glutination titer was recorded and expressed as the GES IN DICTYOSPHAERIUM PULCHELLUM reciprocal of the highest dilution showing positive re- EXPOSED TO COPPER (CHLOROCOC- sults. A total of 31 samples were analyzed; seven Chlo- rophyta species and 11 Rhodophyta showed aggluti- CALES, CHLOROPHYCEAE) nating activity. The species that showed activity variation 1 1 de la Peña, G. , Andrade, L. R. , Amado Filho, G. included the chlorophytes, Caulerpa cupressoides, Caul- M.1 & Rodríguez, M. C.2 erpa paspaloides, Halimeda opuntia and Penicillus capita- 1Lab. de Biomineralizacao, Instituto de Ciencias Bio- tus and the rhodophytes, Chondria litoralis, Digenea sim- medicas, CCS, UFRJ, Brasil; 2Departamento de Cien- plex, Gracilaria cornea and Laurencia obtusa. The cias Biológicas, Facultad de Ciencias Exactas y Natu- agglutinating activity of Liagora farinosa is reported for rales, Universidad de Buenos Aires, 1428 Buenos the first time. This research indicates that ecological Aires, Argentina pressures are an important factor in seaweeds agglutinins synthesis. In an assay addressing the toxicity of copper to Dicty- osphaerium pulchellum, a 48 hours’ exposure of axenic 52 cultures of the alga to metal concentrations ranging GRAPPLING WITH CONFLICT AMONG from 0 to 300 mg LϪ1 caused a significant decrease in INFORMATION SOURCES IN RECON- the growth rate and cell chlorophyll content. Extra- STRUCTION OF THE EARLY EVOLUTION cellular mucilage remotion by controlled sonication OF LAND PLANTS before exposure to copper emphasized chlorophyll Delwiche, C. F.1, Karol, K. G.1, Cimino, M. T.1, & content reduction, but not cellular density diminu- McCourt, R. M.2 tion. Because mucilage acts as a cation interchanger, 1Department of Cell Biology and Molecular Genetics, these results suggested that, during at least the first 48 hours, division rates might be affected by lower Cuϩ2 H.J. Patterson Hall, University of Maryland - College 2 concentrations than chlorophyll content. Ultrastruc- Park, College Park MD 20742-5815; Department of tural observations showed that the normal organiza- Botany, Academy of Natural Sciences, 1900 Benjamin tion of the chloroplasts was altered; they presented di- Franklin Parkway, Philadelphia PA 19103 USA lated lamellae, irregularly arranged with practically no stacking. Copper precipitates were mainly ob- Although a close relationship between embryophytes served outside the plasmalemma or within the extra- (land plants) and charophycean green algae has been cellular mucilage. Electron probe microanalysis con- discussed for over a hundred years, the precise nature firmed these observations, showing only minor of this relationship remains uncertain. This is largely precipitates inside the cells. because of difficulty reconstructing the phylogeny of the basal members of this group. Recent analyses of 51 SSU rDNA, rbcL, and concatenated chloroplast genes have all produced different phylogenies, and none is TEMPORAL AND SPATIAL PRODUCTION OF fully compatible with morphological data. Noteworthy AGGLUTININS IN MARINE MACROALGAE conflict is apparent in the positions of the unicellular FROM THE MEXICAN CARIBBEAN flagellate Mesostigma and the filamentous epiphyte De Lara-Isassi, G., Álvarez-Hernández, S., Chaetosphaeridium. Several phenomena could result in Lozano-Ramírez, C., Hernández-Soto, N. & such incongruence, including problems with the un- Dreckmann, K. M. derlying data (taxon ID, sequence determination, Departamento de Hidrobiología. División de Ciencias alignment, etc.), choice of analytical method, lack of Biológicas y de la Salud. Universidad Autónoma Met- resolution with one or more of the datasets, unrecog- ropolitana-Iztapalapa. Apartado Postal 55-535, D. F. nized paralogy, and horizontal gene transfer. We have 09340, México examined each of these possible sources of incongruence, and have determined that several factors under- lie the apparent conflict among phylogenies. When The presence or absence of secondary metabolites in these factors are taken into account a consensus mo- algae has been long discussed. There are several hy- lecular phylogeny begins to emerge. Despite the long potheses to explain the synthesis of secondary metab- divergence time in question, the prospects for recon- olites in algae as a response to herbivory pressure, struction of land plant phylogeny are good. competence or predation. In this work we made a screening test of chlorophyte and rhodophyte species 53 collected in different sites of the Caribbean sea in order to test them for agglutinins. The extracts were EFFECT OF NITROGEN ADDITION ON A prepared in a phosphate buffer solution 100-mM, pH MIXED SPECIES PHYTOPLANKTON BLOOM 7.2 and filtered using 0.22 ␮m Millipore filters. Agglu- DeYoe, H.1, Buskey, E.2, Jochem, F.2, and tination tests were done in microtiter-plates using for- Villareal, T.2 18 PSA ABSTRACTS

1Biology Department, the University of Texas - Pan face waters are affected by coastal upwelling during American, 1201 W. University Dr., Edinburg, TX boreal winter and spring. Historical information on 78539 USA; 2Marine Science Institute, The University the phytoplankton communities in the basin is scarce. of Texas at Austin, 750 Channelview Dr., Port Aran- In November 1995, an oceanographic time-series sta- sas, TX 78373 USA tion was established at 10.5ЊN - 64.66ЊW. In this study changes in the structure of the phytoplankton community in the upper 100-m layer were studied. The Laguna Madre of Texas is a hypersaline lagoon Monthly samples to determine phytoplankton abun- that in recent years has been dominated by the brown dance and pigment composition (HPLC) were col- tide alga, Aureoumbra lagunensis although a Synechococ- lected from November 1995 to January 1999; water cus-like sub-dominant is typically present. Dominance temperature was used as proxy for upwelling. Surface of A. lagunensis is thought to be due at least in part to waters reached temperatures Յ24Њ C during the up- its nitrogen competitive abilities. A mesocosm study welling season, and surpassed 26Њ C during the rest of was performed to determine if an increase in ambient the year. A total of 300 species were found. Generally, nitrogen concentration would lead to a shift in the the highest number of cells (Ͼ500 cells mlϪ1) were dominant alga. Twelve fiberglass cylinders enclosing measured from January to April every year. Diatoms 1.2 cubic meters of Laguna Madre water were de- were the dominant group in terms of abundance, spe- ployed for 16 days. Four times during this period, am- cies composition (168 species) and pigments (Chl c monium was added (Nϩ mesocosms) to half the me- and fucoxanthin) during this period. The abundance socosms to achieve a post-addition concentration of and marker pigment concentration (peridinin, but- approximately 40 mM. The average initial particulate and hex-fucoxanthin) for other groups support this N/P ratio was 40/1 (SD ϭ 2.9) which recent evidence observation. During the rest of the year diatom and indicates is within the range of N/P ratios for N-lim- total abundance decreased markedly (Ͻ100 cells ited A. lagunensis. In control mesocosms, total cell bio- mlϪ1). Small organisms (Ͻ5 ␮m) became dominant. volume (TCB) of A. lagunensis cells dropped after 4 The maximum concentration values of zeaxanthin days by a factor of four and then increased to a level and But- and Hex-Fuco in this period indicated the slightly above the day 0 value by day 16. In Nϩ meso- presence of cyanobacteria and prymnesiophytes. The cosms, A. lagunensis TCB was unchanged after 4 days sparse and relatively low concentration of Chl b, lutein then doubled by day 16. Despite the differences in fi- and prasinoxanthin indicated that chlorophytes and nal yield, growth rates of A. lagunensis in the two treat- its allies are a minor floral component. ments were similar. The Synechococcus-like organism, showed a four-day lag before TCB in both treatments increased although at a slower rate in the control me- 55 socosms. By the end of the experiment, TCB of A. la- ADVANCES IN A MONOGRAPH OF THE gunensis was two to six-times greater than that of sub- dominant. Despite the nitrogen treatment, A. GENUS GRACILARIA (RHODOPHYTA) IN lagunensis retained dominance. THE MEXICAN ATLANTIC Dreckmann, K. M., De Lara-Isassi, G. & Alvarez- Hernández, S. 54 Departamento de Hidrobiología, División de Ciencias PHYTOPLANKTON COMMUNITY STRUC- Biológicas y de la Salud, Universidad Autónoma Met- TURE: TEMPORAL VARIABILITY IN A TROP- ropolitana-Iztapalapa, Apartado postal 55-535. D. F. ICAL UPWELLING ECOSYSTEM 09340 México Díaz-Ramos, J. R.1, 2, Muller-Karger, F. E.2, Millie, D.3, Troccoli-Ghinaglia, L. E.4, Subero-Pino, S. Some species of the genus Gracilaria Greville S.5, & Varela, R.6 (Gracilariales, Rhodophyta) are the main source of 1Dpto. Biología Marina, Instituto Oceanográfico de agar. For that reason, the taxonomic study of the Venezuela, Cumaná Sucre, Venezuela; 2Dpt. Marine taxon has become relevant for many scholars. In or- Science, University of South Florida, St. Petersburg, Fl, der to bring the Mexican floristics knowledge of the 33701 U.S.A.; 3U. S. Department of Agriculture, c/o genus into the state-of-the-art about it, we have initi- Mote Marine Laboratory, Sarasota, Fl, 34236 U.S.A; ated the needed monography. The character defini- 4Dpto. de Acuicultura, Universidad de Oriente, Boca tion has proved to be the most important task. We 5 have found that the most reliable characters for the de Río, Nva. Esparta, Venezuela; Dpto. de Biología, species delimitation are: general form of the thallus, Universidad de Oriente, Cumaná, Sucre, Venezuela; length and width; form of the axes, length and width; 6Fundación La Salle, Punta de Piedras, Nva. Esparta, branching pattern; number of axes from the holdfast; Venezuela form of the holdfast; presence of constrictions at the base of the branches or not; color; length of the seg- The Cariaco Basin (Southeastern Caribbean Sea) is ments; consistency; form of the apices; length and the largest anoxic basin of oceanic character. Its sur- thickness of the stipes; surface texture of the PSA ABSTRACTS 19 branches, smooth, crispidous, etc; adherency to her- Our ability to track long term climate change in barium paper; cellular forms of the transition from coastal regions is limited in temperate and polar re- cortex to medulla, size and thickness of celular walls gions. Physical oceanographic dynamics in tempera- of the cells involved; number of celular layers of the ture and upwelling events can be recorded as carbon cortex, subcortex (if present) and medulla; form, and oxygen stable isotope signals in carbonate pro- number and distribution of the spermatangial con- ducing organisms. Because coralline algae photosyn- ceptacles; form and size of the cystocarps, if con- thesize, produce calcium carbonate and are widely stricted at the base or sessile; diameter of the ostiole distributed, they may provide a new tool for detecting and if it is apiculated or not; disposition of the car- short-term change. However, little is known about posporangial chains; form of the gonimoblastic cells, how coralline algae incorporate stable isotopes into and form and number of tetrasporangia. A diagra- their calcite thallus structure. The objectives of this matic description for each is provided. study were to determine if growth and isotopic signature differ in articulated coralline algae grown in dif- 56 ferent oceanographic regimes in Monterey Bay. The articulated alga Calliarthron cheiliospororioides was out- PHYLOGENETIC SELECTION OF A RE- planted at three locations varying in seawater temper- SOURCE: A NEW USE FOR CLADISTICS ature and upwelling strength. New algal growth was Dreckmann, K. M., De Lara-Isassi, G. & Alvarez- measured by staining the algae with Alizarin Red and Hernández, S. enumerating the amount of accumulated material at Departamento de Hidrobiología, División de Ciencias the branch tips. Growth rates varied seasonally and Biológicas y de la Salud, Universidad Autónoma Met- spatially. Low-upwelling daily growth rates averaged Ϫ ropolitana-Iztapalapa, Apartado Postal 55-535, D. F., 0.044–0.056 mm day 1, while high-upwelling growth Ϫ1 09340, México rates were 0.083 mm day . Isotope ratios were obtained by analyzing microsampled portions of the alga in a mass spectrometer. Changes in the 18O/16O and A phylogenetic model for the selection of commercial 13C/12C ratios appear to reflect change in seawater resources using the cladistic method is proposed. The temperature and upwelling strength, respectively. group selected as an example was the marine agaro- phyte red algal genus Gracilaria Greville. We suggest the use of the cladistic principle of evolutionary trans- formational series in order to test the quality of agars 58 instead of the assay-herror traditional method that consumes time and budget. If we asume that the PRELIMINARY ANALYSIS OF QUANTITA- “good quality of agar” in extant taxa is a sinapomor- TIVE GENETICS AND PHENOTYPIC PLAS- phic character (but not a reliable taxonomic one), TICITY IN AULACOSEIRA SUBARCTICA then taxa included in the same monophiletic clade in (BACILLAR-IOPHYTA) which the species with “good quality of agar” are, has Edgar, S. M., & Theriot, E. C. a high evolutionary posibility to share that character. Section of Integrative Biology, University of Texas at In order to do this we have to incorporate to the set of Austin, Austin TX 78713 USA available specific characters, those of the taxa actually used as a agar source but not present in the area un- Several clones of Aulacoseira subarctica were isolated der scope. A complete set of the basic cladistic data re- from Yellowstone, Lewis, and East Rosebud Lakes quired for run the most popular program currently in (Montana, Wyoming). Two to four clones from each use (PAUP) are provided. We applied the model to lake were grown in batch cultures under three light in- the Mexican Atlantic species and found that, using tensities, 2, 11.4 and 115 ␮E mϪ2 sϪ1. Clones were con- Gracilaria chilensis and G. cornea as “indicator taxa,” ditioned to their light environment for a three-week and found Mexican populations of G. crassissima, G. period. Inoculants from the conditioned clones taken caudata, G. cervicornis and Gracilariopsis lemaneiformis during log phase of growth, were grown until in log are candidates for a study of yield and agar properties. phase, then samples were collected. Five randomly cho- sen valves for 2 replicates of each clone were examined 57 using a scanning electron microscope and captured on POTENTIAL TOOLS FOR TRACKING film at a magnification of 20,000x. Each image was digi- OCEAN CLIMATE: VARIABILITY IN STABLE tized and quantitative morphometric characters were measured. A preliminary quantitative genetic analysis ISOTOPES IN LIVING CORALLINE ALGAE 1 1 2 was performed on selected characters within each light Dunn, R. A. , Steller, D. L. , & Zachos, J. environment. Plasticity of characters within clones 1 Biology Dept., UC Santa Cruz, Earth and Marine Sci- across the three light regimes were also examined. The ences Bldg., Santa Cruz 95064 USA; 2Earth Sciences amount of variability found within characters in A. sub- Dept., UC Santa Cruz, Earth and Marine Sciences arctica will be discussed in terms of environmental, ge- Bldg., Santa Cruz 95064 USA netic, and microenvironmental sources. 20 PSA ABSTRACTS

59 benthic and pelagic communities and can result in SCALE-DEPENDENT PATTERNS OF DISTUR- million dollar losses for commercial fisheries and BANCE AND RECOVERY IN GIANT KELP mariculture of fin and shellfish. Effective prevention FORESTS and mitigation strategies require an understanding of 1 2 environmental factors that contribute to the forma- Edwards, M. S. & Hernandez-Carmona, G. tion of harmful algal blooms, as well as information 1 Department of Biology, University of California, on the regulation of algal toxicity at the molecular Santa Cruz, CA 95064 USA; 2CICIMAR-IPN, Lapaz, level. To approach the latter aspect, we investigated Baja California Sur, 23,000 Mexico the variation in toxin production of synchronized C. polylepis cultures by means of a sensitive bioassay and We studied spatial variability in giant kelp (Macrocystis by flow cytometry. The results so far obtained show pyrifera) forests at 84 sites along the west coast of significant variation in cellular toxin content and spe- North America in order to assess the impacts of the cific toxin production throughout the sampling pe- 1997–98 El Niño. Our sites spanned the geographic riod of three days. The existence of times in the cell range of giant kelp in the Northern Hemisphere and cycle of high and low levels of toxin production will were surveyed just before, immediately following, sev- be used as the basis for the identification of differen- eral months after, more than one year after, and tially expressed genes and proteins using differential nearly two years after the El Niño. Interspersion of display and 2-D protein gel electrophoresis. Prelimi- sample units allowed us to compare the effects of this nary results concerning the molecular analysis will be disturbance among spatial scales ranging from a few presented as well. meters to more than a thousand kilometers. Variance components analyses revealed that El Niño shifted the relative importance of factors that regulate giant kelp 61 communities from factors acting at the scale of a few CO-OCCURRENCE OF CARRAGEENANS AND meters (local control) to factors operating at hun- AGAROIDS IN GYMNOGONGRUS TORULO- dreds of kilometers (regional control). Moreover, El SUS (GIGARTINALES, PHYLLOPHORACEAE) Niño resulted in a near-to-complete loss of giant kelp FROM ARGENTINA populations throughout nearly two-thirds of the spe- Estevez, J. M., Ciancia, M .& Cerezo, A.S. cies’ range. Evaluation of these effects along with oceanographic data (at the “appropriate” spatial Departamento de Química Orgánica, Facultad de scales), along with closer examination of giant kelp Ciencias Exactas y Naturales, Universidad de Buenos populations in the most severely impacted region Aires, 1428 Buenos Aires, Argentina (Baja) suggested that the among-region differences in giant kelp survival was due, at least in part, to El Niño- The red seaweeds, Gigartina skottbetgii and Sarcothalia induced differences in ocean climate. Giant kelp re- crispata, have commercial value as raw material for the covery following El Niño was also scale-dependent, industrial production of phycocolloids (carrageen- but driven by factors different from those of the dis- ans) in Argentina. The third alga with potencial possi- turbance. Here, we present results for several species bilities for the carrageenan production is Gymnogon- of macroalgae in an attempt to relate the importance grus torulosus. Herein, we report the study of the of El Niño to that of other processes in creating scale- polysaccharide system present in Gymnogongrus torulo- dependent patterns of variability. sus, which contribute to the estimation of the importance of this algae in the seaweed industry. Analysis of the hot water-soluble extract (C1), by FT-IR, methyla- 60 tion and 13C NMR, showed mainly the presence of .(2:1 ف VARIATION IN TOXIN PRODUCTION OF iota/kappa carrageenan hybrid (molar ratio SYNCHRONIZED CULTURES OF CHRYSOCH- The soluble fractions obtained after KCl fractionation ROMULINA POLYLEPIS (PRYMNESIOPHYTA) (F3, 16.1 % of C1) and soluble after alkaline treat- Eschbach, E.1, John, U.1, Reckermann, M.2 & ment and KCl fractionation (F3T3, 34.6% of F3T) Ϫ Ϫ Medlin, L. K.1 gave negative optical rotations ( 15.5 and 55.4, re- 1 spectively), considerably lower than those reported Alfred-Wegener-Institute for Polar and Marine Re- for kappa/iota carrageenans (from 56.1 to 66.5). search, PO Box 120161, 27515 Bremerhaven, Ger- These fractions (F3 and F3T3) have significant quan- many; 2Research and Technology Centre Westcoast of tities of L-galactose (11.1% and 29.8%) and L-3,6-an- Kiel University, Hafentoern, 25761 Buesum, Germany hydrogalactose (19.2% and 4.3%). The direct relationship between the optical rotation and the In European coastal waters toxic blooms of Prymne- percentage of L-galactose indicated that its structural siophytes occur regularly. Chrysochromulina polylepis is a influence is similar in all the fractions. The results highly toxic member of this taxonomic group, which suggest that Gymnogongrus torulosus biosynthesizes a formed a devastating bloom in Scandinavian waters in polysaccharide system with co-occurrence of carrag- 1988. Blooms like these can cause severe damage to eenans and agaroids in the same thallus. PSA ABSTRACTS 21

62 been isolated, indicating that dinoflagellates acquired PHOTOSYNTHESIS IN THE DEEP BLUE SEA: chloroplasts multiple times during evolution. Further- PHOTOPHYSIOLOGICAL RESPONSES OF more, dinoflagellates contain nuclear genes encoding PHAEODACTYLUM TRICORNUTUM TO DY- chloroplast proteins that are not typically found in eukaryotes. These include the type II form of RuBisCO, NAMIC AND STATIC IRRADIANCES and a eubacterial form of glyceraldehyde-3-phosphate 1, 2 2 Evens, T. J. & Chapman, D. J. dehydrogenase (GAPCp) that we have recently char- 1United States Department of Agriculture-Agricultural acterized from Gonyaulax polyedra. The evolutionary Research Service, Southern Regional Research Center, origin of this GAPCp isoform is unclear. It is phyloge- 1100 Robert E. Lee Blvd., New Orleans, LA 70124 netically distant from the Gonyaulax cytosolic form USA; 2Department of Ecology, Evolution & Marine Bi- (GAPC) and from the chloroplast forms (GAPA/B) of ology, University of California, Santa Barbara, CA cyanobacterial origin typically found in photosyn- 93106 USA thetic eukaryotes. It has previously been described only from cryptomonads, raising the possibility that The kinetics of xanthophyll-cycle pigment switching Gonyaulax acquired the gene through lateral transfer. and fluorescence quenching dynamics in the marine We have addressed this issue by examining the phylog- diatom, Phaeodactylum tricornutum were determined in eny of GAPDH genes from other dinoflagellates. We the context of dynamic and static growth light. Cul- have isolated genes from Gymnodinium mikimotoi and tures were grown in a modified photobioreactor capa- Pyrocystis lunula. The predicted protein sequence of ble of producing dynamic light fields which exhibited the G. mikimotoi gene is 47% similar to Gonyaulax attenuation characteristics similar to that of water; GAPC and GAPCp and phylogenetic analysis places these cultures were pre-acclimated to high and low, them in the same eubacterial clade. The predicted static and dynamic, growth-light regimes for at least amino acid sequence of the P. lunula gene is 41% and three days, and then examined under high, static and 37% similar to Gonyaulax GAPCp and GAPC isoforms, dynamic light. Pigment pools varied markedly. The respectively. However, phylogenetic analysis groups it two static light cultures had pigment complements within the clade comprising cyanobacterial and eukary- that were very similar to “traditional” high and low- otic GAPA/B isoforms and shows that it is closely re- light static cultures. The dynamic-light grown cultures lated to the chloroplast form of Euglena gracilis. Thus, had pigment complements, which were very similar to within the Dinophyceae, GAPDH genes of different each other but different from the static-grown cul- evolutionary origin have been recruited to participate tures. The maximum xanthophyll-cycle pigment de- in chloroplast metabolism. epoxidation state attainable under saturating light was equal for all four treatments. Induction of fluores- 64 cence quenching was significantly faster in the static- grown cultures, while xanthophyll-cycle de-epoxida- CLONING, SEQUENCING AND EXPRESSION tion rates did not show as much variation. Minimum OF A HISTONE-LIKE PROTEIN FROM THE irradiances for xanthophyll-cycle induction were cor- PHOTOSYNTHETIC DINOFLAGELLATE related to average growth irradiance. Taken as a GONYAULAX POLYEDRA whole, the results from this work suggest that dynamic Fagan, T. F.1, Li, J. F.1, Chudnovsky, J.1, Rizzo, P. light-grown phytoplankton have a unique photosyn- J.2, & Hastings, J. W.1 thetic functionality that is different from static light- 1Department of Molecular & Cellular Biology, Har- grown phytoplankton. The significance of these ob- vard University, 16 Divinity Avenue, Cambridge MA servations in the context of realistic light fields, and 02138, USA; 2Biology Department, Texas A&M Uni- the photosynthetic response capabilities of algae versity, College Station, TX 77843, USA grown under them will be discussed. The presence of small basic DNA-binding proteins, or 63 histone-like proteins (HLPs), in dinoflagellate nuclei HETEROGENEITY OF CHLOROPLAST has been well documented. Genes for HLPs have been GAPDH GENES IN THE DINOPHYCEAE cloned from Crypthecodinium cohnii (HCc 1 and 2) and Alexandrium fundyense (HAf) but their predicted pro- Fagan, T. F. & Hastings, J. W. tein sequences show no homology to histones from Department of Molecular & Cellular Biology, Harvard other eukaryotes or to bacterial HLPs. The precise University, 16 Divinity Avenue, Cambridge MA role of these HLPs in dinoflagellate nuclei is uncer- 02138 USA tain; the HLP:DNA ratio is too low to facilitate packag- ing of the entire (very large) genome. In order to in- Dinoflagellates provide valuable models for studying vestigate the role of these proteins we have cloned a endosymbiosis and chloroplast evolution. While many gene for a HLP from Gonyaulax polyedra (HGp). Unlike species are heterotrophic, photosynthetic species con- the genes from C. cohnii, the G. polyedra gene contains taining plastids of different evolutionary origin have no introns. It codes for a protein with a predicted mo- 22 PSA ABSTRACTS lecular mass of 10,985 Da, and an isoelectric point of 66 10.5. We over-expressed this protein in Escherichia coli ALGAE AS WATER QUALITY INDICATORS using a construct that expresses the full-length protein FOR A DYSTROPHIC POND with an N-terminal histidine tag, and purified it by Ferguson, E., Mosto, P., Nordone, N., Perez, C. Nickel-affinity and cation-exchange chromatography. While the predicted molecular mass of the fusion pro- III., & Wojs, J. tein is 12,973 Da, similar to sizes observed for acid-sol- Department of Biology, Rowan University, Glassboro, uble G. polyedra nuclear proteins, the relative mobility NJ 08028, USA on denaturing SDS-polyacrylamide gel electrophoresis is 20,000 Da. We attribute the slower mobility in de- The physico-chemical, bacteriological, and algal com- naturing page to the basicity of the protein and pre- position of R.U.Bi.S. Pond were studied since March dict that the relatively faster mobility exhibited by 1999. The pond, located in Cape May County, NJ, is a native HGp is due in part to post-translational modifi- dystrophic body of water, with high sediment:water ra- cation of basic residues. Such modifications have tio and organic matter content creating anoxic condi- been observed in histones and play an important role tions during fall and early winter. Water quality indi- in the regulation of transcription in eukaryotes, a cators based on periphytic algae and water quality function that HLPs may assume in dinoflagellates. indices that are specific to R.U.Bi.S. Pond are being This possibility is being investigated. developed. Such indicators could be used for similar bodies of water and for the restorability of this dystrophic ecosystem integrity. Two sampling sites were studied. Samples were collected weekly, using a per- iphytometer, for seasonal analysis of succession. Sam- ples for water chemistry, bacteriology, and periphytic 65 algae were collected bi-monthly. The predominant al- BIODIVERSITY OF PLANKTONIC DINO- gal species found during summer ‘99 were Phormid- ium, Oscillatoria, Chlorella, and Eunotia. During fall ‘99, FLAGELLATE SPECIES IN MANGROVE the predominant species were Oscillatoria and Phormid- PONDS, PELICAN CAYS, BELIZE ium. In winter, the community was dominated by Chlo- Faust, M. A. rella and Chlamydomonas. Species present year-round Department of Botany, NMNH, Smithsonian Institu- were Nitzschia, Oedogonium, Eunotia, and Navicula. tion, Suitland, MD 20746 USA Data analysis indicated variations among the two sampling sites, with total cell counts and species diversity Information on the population structure of plank- higher at the northern site. Algal cell counts, chlor- tonic dinoflagellates is reported in the coral reef-man- phyll a concentrations, species diversity, and D.O. lev- grove ecosystem at Pelican Cays, Belize. Six sites ex- els were greatest during summer. Biomass, hardness, amined included: Cat Cay, Douglas Cay, Elbow Cay, HPCs and total organic carbon peaked during the Fisherman’s Cay, Lagoon Cay and Manatee Cay. A fall. Nutrients, pH, and coliforms remained constant spectacular and rich dinoflagellate taxa including during the study period. The predominant algae oceanic, coastal and offshore species are illustrated. found were pollution-tolerant genera, categorizing The presence of oceanic species in the studied cays is the pond as highly dystrophic. Species diversity indian unexpected observation since dinolfagellate as- ces indicated that water quality decreased during the semblages are virtually enclosed within ponds bor- fall/winter months, with the southern site being more dered by coral ridges that limits water exchange with environmentally stressed than the northern site. the open ocean except during storm events. I am also reporting significant differences in the dinoflagellate 67 associations among the studied cays. Dominant taxa PHYLOGENY, BIOGEOGRAPHY AND LIFE included 16 Proroperidinium species, 11 Gonyaulax spe- HISTORY EVOLUTION IN THE RED ALGAL cies, and ten Ceratium species. Only six planktonic species were harmful. Bloom forming species included FAMILY PHYLLOPHORACEAE (GIGARTINA- Ceratium furca and Gonyaulax polygramma. A much LES) more diverse authotrophic and heterotrophic di- Fredericq, S. & Lopez-Bautista, J. M. noflagellate population characterizes the Pelican Cays Department of Biology, University of Louisiana at than previously suspected. Some species are reported Lafayette, LA 70504 USA the first time: Protoperidinium belizeanum sp. nov., P. pyrum Balech, P. steidingerae Balech, P. depressum Red algae are exceptional for the great diversity in re- (Bailey) Balech, and P. divergens (Ehrenberg) Balech. productive morphology and for their complex life his- These results demonstrate that the Belizean coral tories. In particular, the family Phyllophoraceae, con- species worldwide, stands out in 100ف reef-mangrove ecosystem is a delicate and species-rich sisting of environment, and as such, should be protected and exhibiting a wide spectrum of unique life history types preserved. that makes it unusually interesting for assessing the PSA ABSTRACTS 23 phylogenetic importance of reproductive traits rela- Department of Cell Biology & Molecular Genetics, Uni- tive to classification criteria. Type of life history and versity of Maryland, College Park, MD 20742, USA position of the reproductive structures on the plant body have traditionally formed the basis for separat- Algae, with their variety of pigmentation and extant ing eleven genera in the Phyllophoraceae; however, evidence of primary to tertiary endosymbiotic states, phylogenetic analyses inferred from three sets of DNA present rich opportunities for exploring evolutionary sequences [chloroplast-encoded rbcL, nuclear large- relationships. A strong link is suggested by the conser- subunit ribosomal RNA gene (LSU), and internal vation of phycobilisome structure between red algal transcribed spacer regions (ITS) of nuclear ribosomal chloroplasts and cyanobacterial progenitors. Although DNA], instead indicate a lack of correlation between phycobilisomes are the major antennae of photosys- type of life history and phylogenetic relationships tem II reaction centers in both groups, a chlorophyll among the established taxa. This lack of correlation (Chl)-carotenoid light-harvesting complex (LHC) dramatically challenges all of the traditional taxon- evolved in rhodophytes around the photosystem I re- omy. The study will answer the question which mor- action centers. LHC-polypeptides of all eukaryotic al- phological features and which aspects of life history gae and green plants have high conservation of 8 pu- evolution can be used as meaningful indicators of tative Chl-binding sites on three trans-membrane phylogenetic relationships in the Phyllophoraceae. helices, yet many different types of Chls and caro- The results are addressed in light of global biogeo- tenoids serve in light harvesting in diverse algal graphic hypotheses for the family. groups. In view of the phylogenetic relatedness of LHC polypeptides (Durnford et al. 1999, J. Mol. Evol. 68 48:59) the Chl and carotenoid-binding capability was examined with pigments from diverse algae. A recom- CHARACTERIZATION OF THE OFFSHORE binant P. cruentum polypeptide, LHCaR1, reconsti- MARINE MACROALGAE FROM THE NORTH- tuted with its own pigments functionally bound about WESTERN GULF OF MEXICO HARD BANK 8.0 Chl a, and 4.0 zeaxanthin, comparable to native its COMMUNITIES polypeptides. Upon reconstitution with diatom pig- Fredericq, S., Phillips, N., Gavio, B., Gurgel, C. ments 7 Chl a, 1 Chl c, and 10 xanthophylls were F., Lin, S. M., Wysor, B., & Lopez-Bautista, J. M. bound per polypeptide, which participated in energy Department of Biology, University of Louisiana at transfer to Chl a. Spinach pigments also bound to the Lafayette, Lafayette LA 70504 USA polypeptide, incorporating a total of 8 Chl (both a and b) and ca. 4 xanthophylls, with energy transfer The upper northwestern Gulf basin is characterized from lutein and Chl b to Chl a. These results suggest by a relatively shallow but well-developed continental that the red algal LHCs retained the flexibility to bind shelf with an extensive system of mid- and outer shelf different types of Chls and carotenoids. Such an an- hard banks of varying origin and composition. Obser- cestral feature may have contributed to the successful vations done by our laboratory while participating in radiation of photosynthetic algae into varied light en- monitoring cruises to the National Marine Sanctuar- vironments. ies of the East and West Banks of the Texas Flower Gardens, Stetson Banks (TX) and Sonnier Banks 70 (LA) reveal a surprisingly different floristic composition among the sites. Several range extensions, new CURRENT STATUS OF THE INVASIVE macro-algal records for the Gulf of Mexico, and new GREEN ALGA CODIUM FRAGILE IN EASTERN species imply a much more complex Algal Zone com- CANADA munity than the one proposed by Rezak et al. (1985). Garbary, D. J. & Jess, C. B. Our ongoing project includes the development of a Department of Biology, St. Francis Xavier University, modern taxonomic, phylogenetic, morphological and Antigonish, Nova Scotia B2G 2W5 Canada genetic database essential to informed management for preservation of biological diversity. It also provides Ten years after the initial discovery of Codium fragile in a framework of seasonal algal composition against eastern Canada on the Atlantic coast of Nova Scotia, which long-term trends and anomalies in algal distri- C. fragile has extended its range considerably to north- bution and health of the Gulf of Mexico can be as- ern Nova Scotia, southern New Brunswick and Prince sessed at future dates. Edward Island (P.E.I.) in the Gulf of St. Lawrence. In all principal areas C. fragile subsp. tomentosoides is 69 present. In two regions of Prince Edward Island, Co- dium is becoming extremely abundant, and is known LIGHT HARVESTING ANTENNAE SYSTEMS: by local fishers as the “oyster thief”. A potential sec- LESSONS FROM SIMPLE ALGAE, THE ROLE ond taxon of Codium was collected in 1999 at three OF SCIENTISTS, AND TRENDS sites in Malpeque Bay where it is locally abundant. Gantt, E. These plants are distinguished from C. fragile subsp. 24 PSA ABSTRACTS tomentosoides by their smaller frond size, flatter utricle nas, Universidad Autonoma de Baja California, tops, smaller mucrons, and smaller gametangia. Prin- Ensenada, B.C., Mexico cipal component analysis distinguishes plants of the two types. The abundance of C. fragile on both hard Generic and species concepts within the red algal as- bottom and soft bottom substrata suggests that it will semblages Halymeniales and Rhodymeniales are dis- become the dominant alga in many subtidal algal cussed for taxa inhabiting the western Gulf of Mexico. communities in eastern Canada. Two principal biogeographic assemblages occur: an off-shore deep-water group (including Coelarthrum clif- 71 tonii, Halymenia spp., Botryocladia spp., Gloiocladia) rep- BIOGEOGRAPHY AND ECOLOGY OF THE resenting remnants of a Tethyan distribution, and a KELP/RED ALGAL SYMBIOSIS near-shore intertidal flora (comprising Rhodymenia, Garbary, D. J.1 & Kim, K. Y.2 Grateloupia and Prionitis) which instead reveals biogeo- 1Department of Biology, St. Francis Xavier University, graphic affinities with the Carolinian Province. These two distinct marine floras will be contrasted phyloge- Antigonish, Nova Scotia B2G 2W5 Canada; netically based on DNA sequence analysis inferred 2 Department of Oceanography and Institute of Marine from chloroplast-encoded rbcL. The generic descrip- Sciences, Chonnam National University, Kwangju tions of Grateloupia and Prionitis are in need of taxo- 500757 Korea nomic revision based on a survey of species from Car- ibbean and Pacific Mexico. A kelp/red algal symbiosis is described from nature based on extensive collections from the San Juan Is- lands, Washington. Kelp gametophytes were found as 73 endophytes in the cell walls of seventeen species of FUNCTIONAL BINDING OF DIATOM PIG- red algae in three different kelp communities. Host MENTS TO A RHODOPHYTE LIGHT HAR- red algae were mostly filamentous (e.g., Pleonosporium VESTING POLYPEPTIDE vancouverianum) or polysiphonous (e.g. Polysiphonia Grabowski, B., Cunningham, F. X., & Gantt, E. paniculata). The kelp gametophytes completed vege- Cell Biology and Molecular Genetics, University of tative and reproductive development in the hosts with Maryland, College Park, MD 20742 USA gametangia formed at the host surface and with sporophytes up to several mm in height being produced while still attached to the host. To date, none A close relationship of light harvesting polypeptides of the kelp gametophytes from nature have been (LHC) of rhodophytes, chromophytes and chloro- identified to genus or species, although the gametophytes is inferred from the amino acid sequence simi- phyte of Nereocystis luetkeana is a potential candidate larity in three transmembrane helices, and from the con- for the symbiosis. Preliminary observations from Nova servation of 8 putative chlorophyll (Chl)-binding sites Scotia and the Isle of Man have not found the associa- (Durnford et al. 1999, J. Mol. Evol. 48:59). Differences tion in the Atlantic Ocean. Laboratory studies in Ko- in Chl and carotenoid pigments have been a major rea successfully reconstructed the symbiosis in the red classification feature. Thus, it was of interest to ascer- alga Aglaothamnion oosumiense using zoospores of tain whether pigments from a diatom (Thallasiosira flu- Undaria pinnatifida but not Laminaria religiosa. Here viatilis) could be functionally inserted into a red algal we outline the development of the symbiosis and dis- (Porphyridium cruentum) polypeptide. A recombinant cuss the potential adaptive significance of the kelp/ polypeptide, LHCaR1, was reconstituted with pigment red algal interaction. extracts from the diatom (Chls a and c, fucoxanthin, diadinoxanthin and ␤-carotene). The pigments were found attached to protein upon separation on sucrose 72 gradients, and on non-denaturing gels. Absorption PHYLOGENETIC AND BIOGEOGRAPHIC and fluorescence excitation spectra revealed individ- AFFINITIES OF THE HALYMENIALES AND ual peaks corresponding to the absorption maxima of RHODYMENIALES (RHODOPHYTA) FROM Chl a at 438/672 nm; Chl c at 463/638 nm; and fucox- THE GULF OF MEXICO anthin at 493/540 nm. Fluorescence emission and CD Gavio, B.1, Fredericq, S.1, Mendoza-Gonzalez, spectra showed functional binding and suitable orien- C.2, Mateo-Cid, L.2, Aguilar-Rosas L. E.3, & tation for energy transfer from Chl c and carotenoids Aguilar-Rosas, R.3 to Chl a. The LHCaR1 successfully folded in the pres- 1Department of Biology, University of Louisiana at ence of the heterologous pigments and bound 7 Chl a, 1 Chl c, 8 fucoxanthin, and 1.9 diadinoxanthin per Lafayette, LA 70504 USA; 2Depto. de Botanica, Es- polypeptide. By comparison, this polypeptide with P. cuela National de Ciencias Biologicas, I.P.N., Mexico cruentum pigments binds 8 Chl a, and 4 zeaxanthins, D.F, Mexico; 3Instituto de Investigaciones, Oceanologi- thus revealing its capability of functionally binding 8 cas, Universidad Autonoma de Baja California, Chls with variations in carotenoid numbers. Such a Ensenada, B.C., Mexico; 4Facultad de Ciencias Mari- trait may have favored the diversification of a large PSA ABSTRACTS 25 family of LHCs and the successful radiation of photo- bind a variety of Chls. The former are all chloroplast- synthetic eukaryotes into different light environ- encoded and have high sequence similarity to their ments. cyanobacterial homologs; the latter are all nucleus-encoded and have a much more complex relationship 74 with each other and their (presumed) cyanobacterial THE SECRET LIFE OF KELPS: PLANKTONIC ancestors. Phylogenetic analysis of the LHC superfam- PROCESSES AND POPULATION DYNAMICS ily protein sequences show that they follow the endosymbiotic history of their hosts and suggest that the Graham, M. H. ancestral cyanobacterial genes were copied to the nu- Scripps Institution of Oceanography, University of Cal- cleus soon after the establishment of the primary en- ifornia San Diego, San Diego, CA 9209 USA dosymbiosis. Both families have members whose role appears to be related to photoprotection rather than Understanding spatio-temporal variability in recruit- light-harvesting, suggesting that these families may ment is vital to studies of kelp population dynamics. have originated as stress-response proteins. In support Research on settlement and post-settlement processes of this, all members of the LHC superfamily bind sig- has suggested that arrival of kelp zoospores to suitable nificant amounts of carotenoid, and much of the vari- substrate is important in limiting kelp recruitment, ation between them resides in the bewildering array yet the role of planktonic processes in kelp popula- of different carotenoids they bind. In fact, it has been tion dynamics has not been studied due to difficulties suggested that this family originated as carotenoid- in sampling and identifying zoospores. I developed a binding proteins and only later acquired Chl (Gantt, method to estimate kelp zoospore abundance from in E. 1998; Photosynthesis: Mechanisms & Effects I, pp. 239- situ plankton samples and used it to study various pro- 246). cesses regulating the availability of giant kelp (Macro- cystis pyrifera) zoospores for settlement. My studies focused on (1) identifying temporal scales over which 76 zoospore abundance is most variable, (2) describing HIGH BREVETOXIN CONCENTRATIONS IN physical and biological processes that regulate this GYMNODINIUM BREVE BLOOMS ALONG variability, and (3) determining the relationship be- THE NORTHWEST FLORIDA COAST DUR- tween zoospore abundance and settlement. I found ING 1999 that short-term variability in zoospore abundance Greene, R. M., Walker, C. C., Murrell, M. C., Ͻ ( 24 hrs) was not due to changes in supply but rather Kurtz, J. C., Stanley, R. S., & Genthner, F. J. dispersion, caused by oscillating hydrodynamic forces (e.g. waves). Long-term variability in zoospore abun- Gulf Ecology Division, National Health and Environ- dance, however, was best explained by the size and mental Effects Research Laboratory, United States En- density of reproductive adult plants, with zoospore vironmental Protection Agency, 1 Sabine Island Drive, abundance being most variable at the scale of days to Gulf Breeze, FL 32561 USA months. Changes in adult reproductive condition caused rapid changes in zoospore abundance suggest- Blooms of the dinoflagellate Gymnodinium breve (i.e. ing that the supply of kelp zoospores is sensitive to en- red tides) produce brevetoxins (PbTx) that negatively vironmental regulation of adult physiology. Thus, un- impact the Gulf of Mexico ecosystem, human health, like with marine animals, these results indicate that and local economies. Characterizing and predicting variability in kelp propagule supply, over scales most bloom events and their impacts requires knowledge likely to affect subsequent settlement and recruit- of G. breve abundance and PbTx concentrations in the ment, is more tightly coupled to demographic and re- water column. We report results from a bloom that productive mechanisms than to physical transport occurred during the fall and winter of 1999 in NW processes. Florida coastal waters. Data were collected from 16 stations on 3 sampling dates (29 Sept., 9 Nov., 1 Dec.), 75 including basic hydrography, nutrient concentra- LET THERE BE LIGHT (BUT NOT TOO tions, G. breve abundances, and brevetoxin concentra- MUCH): MOLECULAR EVOLUTION OF tions. G. breve cells were enumerated using flow cytometry and PbTx’s were isolated from seawater using LIGHT-HARVESTING COMPLEXES dichloromethane (DCM) partitioning. Brevetoxins Green, B. R. were quantified by HPLC-DAD using a C-18 column Botany Department, University of British Columbia, and an acetonitrile-water gradient elution. Literature Vancouver, BC V6T 1Z4 Canada estimates of total PbTx concentration (PbTx’s 1, 2, 3) of cultured and field-collected G. breve suggest a range The light-harvesting antennas common to all photo- in concentration from 7 to 17 pg cellϪ1. We measured synthetic eukaryotes belong to two protein familes: total PbTx levels that greatly exceeded these values the Chl a-binding core complex family (e.g. CP47, [Sept., 47–67 pg cellϪ1 (nϭ5); Nov., 59–126 pg cellϪ1 CP43), and the LHC superfamily, whose members (nϭ3), Dec., 12–63 pg cellϪ1 (nϭ8)]. PbTx-2 was the 26 PSA ABSTRACTS predominant (67–75%) PbTx isomer found in these penicillin. 22 cultures are now available. For the most blooms. PbTx-1 and PbTx-3 were found at 11–22% part, cultures belong to Rhizophydium species. Chytrid- and ND–28% of total PbTx, respectively. ium lagenula (Braun) sensu Scherffel is grown on Tri- bonema gayanum cells. Cultures differ in possible host 77 range, where some have a very wide host range, but EXTRACELLULAR MATRIX PROTEO-GLY- others grow only on the cells of Chlorococcum minutum CANS INVOLVED IN DIATOM ADHESION (from 40 strains of different clorococcalean algae ex- AND MOTILITY amined). Only two Rhizophydium spp. cultures are op- portunists and grow on dead algal cells and organic Gretz, M. R media. Collection is used for the examination of in- Department of Biological Sciences, Michigan Techno- teraction between algae and fungi. logical University, Houghton, MI 49931 USA

Although diatom extracellular matricies are usually 79 thought of exclusively in terms of the beautiful, archi- IMPACT OF STRESS CONDITIONS ON THE tecturally complex silicious frustule, polymers exuded PHOTOSYNTHETIC MACHINERY through the frustule are critical mediators of interac- Grossman, A. R.1, van Waasbergen, L.2, & tions with the external environment. In several spe- Schwarz, S.3 cies, complex proteoglycans appear to be the primary 1Department of Plant Biology, The Carnegie Institution components involved in adhesion and motility. When of Washington, Plant Biology, 260 Panama Street, viewed with high-resolution cryo-scanning electron 2 microscopy methods, the ubiquity and pervasiveness Stanford, CA 94305 USA; Department of Biology, of these polymers was revealed in both freshwater and University of Texas at Arlington, Arlington, TX marine taxa. Monoclonal antibody mapping of carbo- 76019 USA; 3Department of Plant Sciences, The He- hydrate epitopes characterized by NMR, methylation brew University of Jerusalem, 91904 Jerusalem, Israel and monosaccharide analysis and correlated with structural observations by EM revealed an organiza- Organisms sense their environment and attempt to tional pattern far more complex than previously pro- tune their metabolism to ambient conditions to effi- posed. Modeling assembly of extracellular “stalks” in ciently utilize available resources. Cyanobacteria un- the marine biofouling diatom Achnanthes longipes in- der conditions of stress (nutrient limitation, excess volves intracellular sequestering of multiple compo- light) modify the photosynthetic apparatus by elimi- nents, deposition at the protoplasmic membrane/ nating most photosystem II activity and degrading diatotepum interface, transport through the multilay- their light-harvesting complex or phycobilisomes ered diatotepum and holes in the silica, extrusion (PBS). We have identified cyanobacterial mutants that from the frustule, and assembly into a very complex cannot acclimate normally to nutrient deprivation. multi-laminate biocomposite structure. The mecha- One of these mutants has a lesion in a gene encoding nism of extracellular polymer participation in motility a small polypeptide designated NblA that appears to is complex in a different way, as some current models target the PBS for degradation during nutrient limita- of raphe associated motility involve cytoskeletal inter- tion. A second lesion is in the nblB gene, which en- actions and molecular motors. codes a polypeptide with homology to a family of lyases involved in attaching chromophores to apophy- 78 cobiliproteins. This protein may remove bilin chro- CULTURES OF CHYTRIDS - PARASITES OF mophores from phycobiliprotein subunits prior to ALGAE IN BIOLOGICAL INSTITUTE OF their degradation. A third mutant is defective in nblR, PETERSBURG UNIVERSITY which encodes a transcription factor that controls some of the “general” responses that occur during any Gromov, B. V., Mamkaeva, K. A., & Pjusch, A.V. of a number of different stress conditions. It is re- Laboratory of Microbiology, Biological Institute of St. quired for degradation of PBS and appears to be nec- Petersburg University, Oranienbaumskoye sch., 2, Stary essary for controlling photosynthetic activity during Peterhof, St. Petersburg,198904 Russia both nutrient limitation and high light conditions; this control is critical for survival of cells during condi- During our survey of chytrids occuring on algae in tions of environmental stress. A fourth mutant is al- fresh waters in the northwestern part of the Russian tered in nblS, which encodes a sensor kinase that Federation we never observed mass development of plays a role in regulating both nutrient stress and high parasites, but if cultures of Chlorococcum minutum Starr light responses. This sensor protein has a PAS do- or Tribonema gayanum Pasch. were inoculated with a main, appears to binds a flavin, and integrates the re- sample of water (0.5 L), the parasites appeared in sponse of the cell to a variety of stress conditions; it 10% of the cases. Two-clonal (alga and parasite) cul- may sense the redox status of the cell. I will present a tures were obtained by plating of the material on the model that describes how cyanobacteria sense and re- lawn of algal cells on the solid medium with benzyl spond to environmental change. PSA ABSTRACTS 27

80 Despite a recent body of literature, the species of MOLECULAR STUDY OF THE TOXIC ALGAE Gracilaria recognized for the Gulf of Mexico are still DINOPHYSIS SPP. FROM THE FRENCH incompletely characterized, misidentified, and spe- COAST cies limits not well defined due to huge morphologi- 1 2 3 1 cal plasticity and overlapping habits. To better charac- Guillou, L. , Nezan, E. , Gentien, P. & Barbier, G. terize these taxa and evaluate their taxonomic 1 IFREMER Brest, DRV/VP/CMM, BP 70, 29 280 relationships, we provide a chloroplast-encoded rbcL Plouzané, France; 2IFREMER Concarneau, DEL/CC, phylogeny encompassing primarily Gulf, western At- 13 rue de Kérose, Le Roudouic, 29187 Concarneau lantic, and Caribbean species. Our results indicate the cedex, France; 3IFREMER La Rochelle, DRV/ need to resurrect older, validly published names cur- RA/CREMA, Place du séminaire, BP 7, 17137 rently placed in synonymy under other species of L’Houmeau, France Gracilaria, and to describe new species. For Gracilaria tikvahia, in particular, a combination of DNA se- Dinoflagellates of the genus Dinophysis are agents of quences [rbcL, and internal transcribed spacer re- Diarrhetic Shellfish Poisoning (DSP). They occur gions (ITS) of nuclear ribosomal DNA] from speci- along the French coast and affect shellfish exploita- mens collected across a wide biogeographic area tion during most of the year (during spring, summer (Nova Scotia, Canada, to Las Coloradas, Yucatan Pen- and autumn). Because this species is difficult to culti- insula) successfully promotes the integration and cor- vate, very little is known about this organism. The first relation of molecular phylogenies and morphology problem is the species-delineation within this genus with biogeographic hypotheses. which is sometimes unclear based upon the solely on morphological features, in particular for the complex D. acuminata (D. cf. acuminata,, D. cf. norvegica, D. 82 cf.sacculus, and D. skagii) or the complex D. sacculus PHYLOGEOGRAPHY AND WITHIN-STREAM (D. sacculus and D. pavillardii). The second problem is GENETIC VARIATION OF BATRACHOSPER- its detection in natural samples. French Dinophysis MUM HELMENTOSUM (RHODOPHYTA) USING blooms have been reported to be toxic under 100 INTER-SIMPLE SEQUENCE REPEATS Ϫ cells L 1, a concentration which corresponds to less Hall, M. M. & Vis, M. L. Ϫ1 than 1 cell 10-mL , as determined by the Utermöhl Department of Environmental & Plant Biology, Ohio method of enumeration. Molecular tools may help to University, Athens, OH 45701 USA resolve these two kind of problems. During one year (spring 1999 to spring 2000), more than 100 fixed samples containing Dinophysis spp. cells were collected A relatively new molecular marker technique, inter- along the French coast by the French monitoring net- simple sequence repeats (ISSR), was used to assess the work (or REPHY; http://www. ifremer.fr). The ge- within-stream reach genetic variation and phylogeog- netic diversity of Dinophysis spp. was studied by se- raphy of the freshwater red alga, Batrachospermum hel- quencing and analysis of ribosomal DNA genes. We mentosum. The within-stream reach study was under- found that sequences were hightly conserved between taken in Southeastern Ohio, where 58 individuals species or within the D. acuminata or D. sacculus com- were collected from an approximately 200 m stream plex. Two oligonucleotide probes, specific to these length. Individuals appeared to be congregated into complex groups, were designed. Their specificity and three distinct areas, with no plants between areas. Us- sensitivity are actually tested on natural samples by a ing three primers, 100 polymorphic bands were PCR-based assay. Furthur investigation will include scored. Although it was hypothesized that genetic vari- the development of standard molecular diagnostics ation would reflect physical distance, the results due to their rapid and sensitive detection in natural showed six distinct genetic groupings, some of which samples. consisted of physically distant individuals. Overall, genetic diversity was greater among individuals than between geographic and genetic groups. To investigate phylogeography, 11 stream reaches (3 from Ohio and 81 one each from Connecticut, Massachusetts, Rhode Is- GRACILARIA FROM THE GULF OF MEXICO, land, North Carolina, Tennessee, Indiana, Michigan WITH SPECIAL EMPHASIS ON GRACILARIA and Louisiana) were sampled throughout the alga’s TIKVAHIAE BASED ON TWO MOLECULAR known distribution in North America. Approximately 15 individuals were collected per stream for ISSR DATASETS 1 1 2 analysis. Five primers, yielding 243 polymorphic Gurgel, C.F. , Fredericq, S. , & Norris, J. N. bands, were used to examine variation among all indi- 1 Department of Biology, University of Louisiana at viduals. Neighbor-joining trees generated from the Lafayette, LA 70504 USA; 2Department of Botany, Dice, Jaccard and Excoffier coefficients showed that NMNH, Smithsonian Institution, Washington D.C., individuals from the same stream formed a clade. 20560 USA Among streams there was no distinct correlation be- 28 PSA ABSTRACTS tween geographic distance and genetic similarity. ment, Roger Williams University, Bristol, RI 02809 Genetic groupings varied slightly among distance co- USA efficients employed. Michigan and Tennessee, Con- necticut and Rhode Island, and Indiana and Massachu- Since 1994, when Grateloupia doryphora (Halymeniaceae, setts streams consistently showed the same relationship, Rhodophyta) was first detected in Rhode Island, the but the relationships among the three Ohio streams species has spread to the northern portions of Nar- and Louisiana stream were variably related to each ragansett Bay and onto the open coast of Rhode Is- other. land Sound. Specimens collected at 5 m depths off North Prudence Island reached 175 cm in length and 83 establish this alga as the largest member of the Florideophyceae on North Atlantic shores. Percent MACROALGAL TISSUE NUTRIENTS AS INDI- cover of populations is seasonal: highest in fall (Sep- CATORS OF NITROGEN AND PHOSPHORUS tember through November) and lowest in spring STATUS IN THE FLORIDA KEYS (March through May). Monthly measurements at Hanisak, M. D. & Siemon, L. W. three stations in Narragansett Bay show significant Harbor Branch Oceanographic Institution, Fort Pierce, seasonal differences (p Ͻ 0.01) over two annual cy- FL 34946 USA cles. Artificial substrata placed in the field at known periods allowed measurements of growth rates on in- This study used the tremendous biochemical and eco- dividual thalli. Laboratory culture clarified the se- logical diversity of macroalgae to assess nitrogen and quence of life history stages that make this species a phosphorus availability at a broad, ecosystem-level successful contender for space. scale in the Florida Keys and nearby waters. Spatial variation in tissue nutrients (carbon, C; nitrogen, N; phosphorus, P) of dominant macroalgae were as- 85 sessed, both as ratios and absolute values, along 12 inshore-offshore transects in the Florida Keys and at 10 A REEXAMINATION OF THE SYSTEMATICS stations in nearby Florida Bay. The resulting detailed OF THE ACROCHAETIALES (RHODOPHYTA) analysis demonstrated spatial and temporal patterns USING LARGE-SUBUNIT RDNA SEQUENCE in macroalgal tissue nutrients. The transect data re- DATA vealed no universal inshore-offshore patterns in tissue Harper, J. T. & Saunders, G. W. nutrients and no obvious “hotspots” of nutrient en- Department of Biology, University of New Brunswick, richment. Similarly, when data were compared among Fredericton, NB, E3B 6E1, Canada segments, there was no universal geographical pattern in tissue nutrients for all species. The most striking re- The taxonomic history of the red algal order Acrocha- sult was that the N and P status of macroalgae in Flor- etiales is chaotic. There is no consensus in the litera- ida Bay was significantly different than other loca- ture as to how many genera should be recognized or tions. Macroalgae collected from Florida Bay generally in the assignment of the over 400 species to these gen- had higher N and lower P levels than algae collected era. Morphological and anatomical studies have pro- elsewhere. The most common inshore-offshore pat- vided a suite of possible characters to delineate gen- tern was higher %N and lower %P availability inshore; era within this order, but there have been major however, limited inshore-offshore differences in N:P discrepancies in the assessment and use of these fea- ratio suggests that both nutrients were generally tures. The phylogenetic placement of the Acrocha- readily available in proportional amounts required by etiales has also been the focus of debate. Once thought the various species. Most species in this study had to be the most ancestral florideophyte lineage, recent higher %N, and to a lesser extent, higher %P and %C molecular systematic studies have illustrated that this in March than in July. Based on the published litera- order is a derived lineage closely related to the Nema- ture on other species of macroalgae, it appears that N liales and Palmariales. Phylogenies using sequences of and P are generally available in sufficient quantities the small-subunit (SSU) rDNA have strongly sup- that most macroalgal growth is not limited by either ported two very divergent lineages within a possibly nutrient. polyphyletic Acrochaetiales. The relationships between these two groups and among other closely related 84 rhodophyte orders were not resolved. We have gener- GRATELOUPIA DORYPHORA HAS ESTAB- ated large-subunit (LSU) rDNA sequence data for representatives of the Acrochaetiales and related taxa. LISHED RESIDENCY IN RHODE ISLAND Distance and parsimony phylogenies based on LSU WATERS and combined SSU and LSU data will be presented. Harlin, M. M.1 & Villalard-Bohnsack, M. 2 The increased phylogenetic signal afforded by this ap- 1Department of Biological Sciences, University of Rhode proach will shed light on previous conundrums in the Island, Kingston, RI 02881 USA; 2Biology Depart- systematics of this group. PSA ABSTRACTS 29

86 88 INTRAGENOMIC NRDNA ITS POLYMOR- BIOLUMINESCENCE IN THE MARINE DINO- PHISM IN THE STEPHANODISCUS NIAGARAE FLAGELLATE PYROCYSTIS LUNULA COMPLEX (BACILLARIOPHYCEAE) Heimann, K.1, Matuszewski, J.1, Stiffey, A. V.2 & Hartung, L. L , Goertzen, L. R. , Theriot, E. C. Klerks, P. L.1 Department of Integrative Biology, The University of 1Department of Biology, University of Louisiana at Texas at Austin, Austin, Texas 78713 USA Lafayette, Lafayette, LA 70504 USA; 2Lumitox Gulf L.C., Environmental Testing Laboratory, 1928 B Cor- Intragenomic nrDNA ITS variability was examined in porate Square, Slidell, LA 70458 USA representative species of the Stephanodiscus niagarae complex. PCR was performed on DNA extracted from Marine dinoflagellates are the main contributors to a monoclonal cultures, and sequence variability de- phenomenon commonly known as “phosphorescence termined using standard cloning techniques. Pre- of the sea”. Several investigators using different di- liminary data from all species reveal intragenomic noflagellate species have shown that dinoflagellate bi- polymorphism. ITS sequence data is being used to de- oluminescence is regulated by a circadian rhythm. lineate closely related species of algae and polymor- Diverse bioluminescent systems exist in different or- phisms are potentially problematic for phylogenetic ganisms; however, all systems utilize an enzyme lu- reconstruction and identity. We are exploring the ex- ciferase and the substrates luciferins, which show in- tent of polymorphism in other freshwater Thalassior- ter-species cross-reactivity. In marine dinoflagellates, siraceae, including Stephanodiscus hantzschii fo. tenuis luciferase and luciferin are localized in specific or- and Cyclostephanos invisitatus. ganelles, termed scintillons, which are usually located in close proximity to the vacuole during their active state. Bioluminescence is stimulated by mechanical stress or by acidification of the medium. Nicolas and co-workers (1987, J. Cell Biol. 105: 723-735) suggested that bioluminescence is triggered by an acidification of the scintillon caused by events that depolarize the 87 tonoplast (proton trigger model). However, little is SYSTEMATICS OF ULVACEAE (ULVOPHY- known about the signal transduction cascade that re- CEAE, CHLOROPHYTA) USING NUCLEAR lays the mechanical stimulus perceived at the plasma AND CHLOROPLAST DNA SEQUENCES membrane to the tonoplast. This study investigates the response of the bioluminescent system of Pyrocystis Hayden, H. S. & Waaland, J. R. lunula to various parameters such as age of culture, Department of Botany, Box 355325, University of light quality and quantity, disturbance (handling), Washington, Seattle, WA 98195 USA sensitivity to chemicals, etc. to determine, if the bioluminescent response of P. lunula suitable for measur- Ulvaceae are morphologically simple, cosmopolitan ing environmental toxicants. The assay system used green macroalgae. Family members, particularly spe- measures bioluminescence in response to mechanical cies of Ulva and Enteromorpha, are prevalent in coastal stimuli or acidification allowing us to determine, if ecosystems and responsible for “green tide” events the response varies amongst the two different types of around the world. Little is known about the evolution- stimulation under different experimental conditions. ary history of Ulvaceae. A lack of reliable, non-molec- The use of cell-permeant inhibitors for certain signal- ular systematic characters has thwarted attempts to ing pathways in this assay may help to biochemically diagnose natural groupings within Ulva and Enteromor- characterize events involved in signal transduction pha and among these and other putative Ulvaceae from the plasma membrane to the scintillon. genera. Our study addresses several questions: 1) What are the phylogenetic relationships among genera commonly placed in Ulvaceae (Chloropelta, Entero- 89 morpha, Ulva, Ulvaria); 2) Where do problematic gen- REPRODUCTIVE, CULTURE AND REGENER- era such as Blidingia, Capsosiphon, Kornmannia, and ATION STUDIES OF THE EDIBLE RED ALGA Percursaria belong; and 3) What are the natural group- CALLOPHYLLIS IN CHILE ings of taxa within these genera? We address these questions using nuclear and chloroplast DNA se- Hernández-González, M. C., Aroca, G., Filœn, L. quences. Phylogenetic analyses support a monophyl- & Buschmann, A. H. etic Ulvaceae consisting of Chloropelta, Enteromorpha, Departamento de Acuicultura, Universidad de Los La- Percursaria, Ulva and Ulvaria. The systematic position gos, Casilla 933, Osorno, Chile of Blidingia, Capsosiphon and Kornmannia, and evolutionary relationships within selected genera will be In Chile, the demand of edible seaweeds has in- discussed. creased during recent years and Callophyllis variegata 30 PSA ABSTRACTS is one of the most demanded species. This study sum- Marine Biology Research Division, Scripps Institution marizes information on phenology, aspects, in vitro of Oceanography, University of California, San Diego, culture and vegetative propagation methods for Callo- 9500 Gilman Dr., La Jolla CA 9209 USA phyllis. Results indicate that spore production occurs mainly during winter, and recruitment of new plants We have cloned and characterized the first nitrate appear in nature in the spring. Culture studies indi- transporter genes in a marine organism, from the dia- cate that spores presented higher germination and Ϫ2 Ϫ1 tom Cylindrotheca fusiformis. A cDNA clone and two ge- growth rates at 8Њ C and 10 to 12 ␮mol m s . Fur- nomic sequences, NAT1 and NAT2, were isolated. thermore, these results indicate that this species pre- The sequences were highly conserved, with only 9 out sents a high potential for regeneration from its hold- of 484 amino acids differing. At least four copies of fast. The manipulation of temperature, light and NAT genes were present in C. fusiformis, and multi- culture medium enhances the regeneration process ple copies were present in other diatom species. NAT and growth of Callophyllis in the laboratory. transcript abundance was high in cultures grown in the presence of nitrate, at nearly the same level during nitrogen starvation, and also high in urea-grown 90 cultures. Lower mRNA levels occurred in nitrite- PHYLOGENY OF ZYGNEMOPHYCEAE BASED grown cultures. Transcript levels were highly re- ON COXIII GENE SEQUENCE DATA pressed with NH4Cl or NH4NO3 as the nitrogen Hewitt, D.1, Karol, K. G.2, & McCourt, R. M.3 source, although very low amounts were detected. 1Department of Biology, University of Pennsylvania, NAT mRNA levels were not directly regulated by light Philadelphia, PA 19104; 2Department of Cell Biology or dark. NAT mRNA levels varied, suggesting that ni- and Molecular Genetics, H. J. Patterson Hall, Univer- trate uptake was not continuous, during progression 3 through the cell cycle. The results suggest that tran- sity of Maryland, College Park, MD 20742; Department scriptional control contributes significantly to the of Botany, Academy of Natural Sciences, 1900 Ben- overall control of nitrate uptake in C. fusiformis. The jamin Franklin Parkway, Philadelphia, PA 19103 cloning of the nitrate transporter genes provides a new tool for investigating diatom nitrogen uptake and Molecular phylogenetic analysis of the conjugating metabolism. In addition, the regulation of NAT ex- green algae (Class Zygnemophyceae) using nuclear pression by nitrogen source is likely to be useful in de- (SSU rDNA) and chloroplast (rbcL) gene sequences veloping techniques to specifically control the expres- has resolved hypotheses of relationship at the class, sion of genes fused to NATregulatory sequences in order, and family levels, but several key questions will transgenic diatoms. require data from additional genes. Based on SSU and rbcL sequences, the Zygnemophyceae and Des- midiales are monophyletic, and families of placoderm 92 desmids are distinct clades (Desmidiaceae, Peniaceae, A MOLECULAR MOTOR FOR GLIDING Closteriaceae, and Gonatozygaceae). In contrast, the MOTILITY IN CYANOBACTERIA Zygnemataceae and Mesotaeniaceae are paraphyletic, Hoiczyk, E. although whether these two traditional families con- Laboratory of Cell Biology, The Rockefeller University, stitute a clade is uncertain. In addition, relationships of genera within families have proven resistant to res- New York, NY 10021 USA olution with these two oft-used genes. We have sequenced the coxIII gene from the mitochondrial ge- Motile microorganisms either swim, by using flagella nome to address some of these ambiguous portions of or glide over surfaces by mechanisms that are poorly the phylogeny of conjugating green algae. The coxIII understood. In cyanobacteria, gliding motility ap- gene is more variable than rbcL or SSU rDNA and of- pears as a relatively slow and smooth surface-associ- fers greater resolving power for relationships of gen- ated translocation in the direction of the long axis of era. We present preliminary analyses of coxIII se- the filaments at rates up to a few micrometers a sec- quences from each of the traditional families of ond. Many filamentous species translocate in a highly Zygnemophyceae and contrast the resulting topolo- coordinated manner. Translational movements are gies with those derived from nuclear and chloroplast usually accompanied by revolutions around the long genes. axis of the filament. While moving, the cyanobacteria secrete slime which is left behind as a twisted and col- lapsed thin tube. The observation of the slime secre- 91 tion process shows that the mucilage is formed as fine bands that emerge in close proximity to the cells cross CLONING AND CHARACTERIZATION OF walls. Ultrastructural studies have revealed that the cy- NITRATE TRANSPORTER GENES FROM anobacteria possess at their cross walls complex, pore- THE DIATOM CYLINDROTHECA FUSIFORMIS like organelles, which might be involved in slime se- Hildebrand, M. & Dahlin, K. cretion. As each cell possess two different sets of pores PSA ABSTRACTS 31 pointing in opposite direction, the coordinated activ- 94 ity of these structures could explain how the filament SIGNIFICANCE OF PHYLOGENETIC SYS- can reverse the direction of locomotion. Further- TEMATICS FOR THE BIOGEOGRAPHY OF more, ultrastructural studies have shown that rotating THE MARINE RED ALGAE cyanobacteria possess cell surfaces formed by parallel, 1 2 helically arranged surface fibrils. As the arrangement Hommersand, M. H. , Fredericq, S. , & 3 of these fibrils corresponds with the path of the fila- Freshwater, D. W. ments during locomotion, it might be imaginable that 1Department of Biology, University of North Calolina, these fibrils serve as screw thread guiding the rotation Coker Hall, Chapel Hill, NC 27599 USA; 2Department of the filaments, with the necessary thrust for locomo- of Biology, University of Louisiana at Lafayette, Lafay- tion being derived from the secretion of slime using ette, LA 70404 USA; 3Center for Marine Science Re- the pores at the cross walls. search, 5001 Masonboro Loup Rd., Wilmington, NC 28409 USA

Hovencamp (1997) recommends that geographical information can be extracted from cladistic analyses 93 of phylogenetic data in which the Earth’s history is resolved in terms of vicariance events that established EXPERIMENTAL STUDY OF PHYTOPLANK- barriers to migration. Nodes in a cladogram that spec- TON SPECIES COMPOSITION, ALTERNATE ify two sister groups which do not overlap in their dis- STATES, AND COMMUNITY BREAKPOINTS tributions are taken as evidence for a vicariance event ALONG A PHOSPHORUS GRADIENT and the sequential order of cladogram nodes leads to Holz, J. C.1, Hoagland, K. D.1, & Joern, A.2 a procedure whereby the sequence of vicariance 1School of Natural Resource Sciences, University of Ne- events can be reconstructed. For red algae, two such braska, 103 Plant Industry, Lincoln, NE 68583 USA; events are the persistence of the northward extension 2School of Biological Sciences, University of Nebraska, of the eastern end of Gondwanaland across a cool to 348 Manter Hall, Lincoln, NE 68583 USA warm temperature gradient with the formation of present-day Australasia, and the opening of the Tethyan Ocean followed by closure of the Tethyan A model combining algal mortality due to selective Seaway between Africa and Eurasia. Phylogenetic hy- zooplankton grazing with the Monod model of phy- potheses related to the first of these events are seen toplankton growth was used to predict phytoplankton among genera belonging to the Bonnemaisoniaceae, species composition along a gradient of phosphorus Gracilariaceae, Kallymeniaceae, Gigartinaceae, and (P) concentration and zooplankton grazing pressure. Delesseriaceae. A Tethyan origin and distribution is Model predictions were compared to the results of a exemplified in part by families that comprise the So- mesocosm experiment of phytoplankton species com- lieriaceae complex. Orders such as the Rhodyme- position along a range of P concentrations of five to niales, Halymeniales and the families Ceramiaceae 115 ␮g LϪ1 and potential grazing loss rates of 0.001 to and Rhodomelaceae contain taxa that fall partly into 0.27 dayϪ1. The effect of the P gradient was measured the first and partly into the second category. Phyloge- by monitoring phytoplankton and zooplankton spe- nies are constructed from rbcL sequence data and cies composition and biomass, and physical and compared to the morphological evidence. The biochemical parameters for seven weeks in 12 fiberglass geographical speculations resulting from these obser- tanks (5500 L) filled with lake water and associated vations are preliminary in nature and can only be con- plankton. P concentrations were manipulated so that firmed or refuted with addtional data and more tanks were evenly distributed along the gradient. Us- refined analytical techniques. ing laboratory derived Monod growth constants for P and literature values of phytoplankton selectivity coefficients, zooplankton filtering rates, and zooplankton 95 assimilation efficiencies, the model correctly pre- THE COLONIAL GREEN ALGA ASTREPHO- dicted (1) the existence of alternate community MENE GUBERNACULIFERA DISPLAYS A states, (2) breakpoints between the alternate states CHEMORESPONSE TO ACETATE which are similar to the P concentrations defining Vollenweider’s lake trophic states, and (3) phy- Hoops, H. J., Cocina, A. E., Binder, D. S. and toplankton species composition along the P gradient Widjaja, A. in the mesocosm study. These results suggest that the Biology Department, State University of New York at trade-off between competitive ability for P and edibil- Geneseo, 1 College Circle, Geneseo, NY 14454 USA ity is a primary factor structuring phytoplankton communities, and that multiple states exist which may be Astrephomene gubernaculifera is a colonial green alga ca- consistent with the long-standing P-based lake trophic pable of growth on sodium acetate in the dark. Be- classification. cause heterotrophic organisms often have mecha- 32 PSA ABSTRACTS nisms to detect and respond to food sources, we planned for the canal system to reduce algal growth tested the response of A. gubernaculifera to a number and related MIB and geosmin concentrations. of potential chemoeffectors. Acetate elicits strong chemoaccumulation in three different behavioral as- 97 says. However, there was no chemoaccumulation in response to the carbohydrates xylose, ribose, glucose, A SYSTEMATIC STUDY OF GIGAR-TINACEAE galactose, mannose, arabinose, fructose, maltose, lac- FROM PACIFIC NORTH AMERICA BASED tose, and sucrose; the amino acids asparagine, argin- ON MOLECULAR AND MORPHOLOGICAL ine, cysteine, glutamine, glycine, histidine, isoleucine, EVIDENCE lysine, phenylalanine, serine, threonine, and hydrox- Hughey, J. R. & Hommersand, M. H. yproline; or glycerol. Interestingly, A. gubernaculifera Department of Biology, University of North Carolina, did respond to propionate. This compound is Chapel Hill, NC 27599 USA structurally related to acetate, but is incapable of supporting growth in the dark. This implies that the Greater than 50 species of Gigartinaceae have been chemosensory response in A. gubernaculifera is not the described from Pacific North America, about half of direct result of metabolic changes but rather involves which are currently recognized. Although the family a specific chemical receptor and subsequent internal is treated extensively in the taxonomic literature, signaling pathway. We are presently analyzing swim- many of the species are still confused and a compre- ming patterns in colonies exposed to changes in ace- hensive revision is required. We sequenced the rbcL tate concentration to test several alternate models (RuBisCO) gene and ITS (Internal Transcribed that could lead to chemoaccumulation. Spacer) 1, 2, and 5.8S regions from a large number of recent collections and identified a discrete of number 96 data sets. These were analysed in comparison with the ALGAL-RELATED TASTES AND ODORS IN morphological evidence for each of the taxa. Uncer- tain of the possibility that our operational taxonomic PHOENIX WATER SUPPLY: PRELIMINARY units may not correspond to the types, we developed a REPORT protocol for isolating PCR-friendly DNA from herbar- 1, 2 1 1 Hu Q. , Dempster T. , Lowry D. , Sommerfeld ium specimens, some reaching back as far as 1670. M.1, Westerhoff, P.2, Bruce, D.2, Nguyen, M. L.2, The DNA profiles of types and historically important & Baker L. 3 specimens were compared to those for recently col- 1Department of Plant Biology, Arizona State Univer- lected silica gel-dried and formalin-fixed material and sity, Tempe, AZ 85287 USA; 2Department of Civil and assigned correct names. Species studied ranged from Environmental Engineering, Arizona State University, Alaska to Mexico and the Gulf of California and were Tempe, AZ 85287 USA; 3Backer Environmental Con- compared to outgroup taxa from Pacific South Amer- sulting, 1134 E. Vinedo Lane, Tempe, AZ 85284 USA ica and the Southern Ocean. Particular attention was paid to variations in morphology as they relate to habitat with emphasis on the presence or absence of dif- Frequent episodes of algal-related tastes and odors (T ferent morphological forms among sympatric and al- & O) in drinking waters in metropolitan Phoenix, Ari- lopatric populations. We recognize 10 species in zona prompted initiation of a three-year project in Chondracanthus (including one new combination and July 1999 to investigate the occurrence of T & O me- one new species) and 16 species in Mazzaella (includ- tabolites and to develop a comprehensive manage- ing two new combinations and two new species). Fi- ment strategy to reduce the problems in drinking wa- nally, we tested a phylogenetic hypothesis inferred for ter supplies in arid environments. Two metabolites, 2- the Gigartinaceae from rbcL sequences for congru- methylisoborneol (MIB) and geosmin, have been ence with one generated from ITS sequences. identified as compounds responsible for the earthy- musty tastes and odors in water supplies. Both were detected in the water supply system, including source 98 rivers, reservoirs, canal delivery system and water QUALITATIVE AND QUANTITATIVE STUD- treatment plants. Higher concentrations of MIB and IES OF THE SWIMMING BEHAVIOR OF geosmin occurred in distribution canals than in the HINCKSIA IRREGULARIS SPORES (PHAEO- upstream reservoirs indicating that significant production of the T & O compounds occurs within the PHYCEAE) canal system. A baseline-monitoring program has Iken, K. B., Amsler, C. D., Greer, S. P., & been established for the complex water supply system, McClintock, J. B. with special emphasis on the canal system. Efforts are Department of Biology, University of Alabama at Bir- underway to investigate possible correlations between mingham, Birmingham, AL 35294 USA physical/chemical parameters, algal composition and biomass, with the occurrence of MIB and geosmin. In The swimming behavior of spores of the brown alga addition, several physical and chemical treatments are Hincksia irregularis was analyzed using computer-assisted PSA ABSTRACTS 33 motion analysis. We distinguished five main swim- 100 ming patterns: straight paths, search circles, orienta- ENDOMEMBRANE ULTRASTRUCTURE AND tion, gyration, and wobbling. We suggest different POSSIBLE CHLOROPLAST PROTEIN IMPORT functional values for the individual swimming pat- PATHWAY IN HETEROSIGMA AKASHIWO terns. Straight paths, search circles, and orientation are different but all may be important in small-scale (RAPHIDOPHYCEAE) movements in the benthic boundary layer. As such, Ishida, K., Cavalier-Smith, T., & Green, B. R. they could enable a spore to find a suitable microenvi- Department of Botany, University of British Columbia, ronment for germination and growth. Gyration oc- Vancouver, BC V6T 1Z4 Canada curs during the initial reversible phase of adhesion that can lead to settlement. Wobbling is typical for ir- Chloroplasts in heterokont algae probably originated ritated or mechanically damaged spores and does not from a red algal endosymbiont which was engulfed seem to be a typical pattern associated to settlement. and retained by a eukaryotic host, and are sur- The dominant swimming patterns changed with spore rounded by four envelope membranes. The outer- age (10 Ϯ 5 to 60 Ϯ 5 min of spore age), with young most of these membranes is called chloroplast ER spores mainly swimming in straight paths and search (CER) and usually connects with the nuclear enve- circles and older spores in orientation and gyration. lope. This information, however, is based mainly on This change in swimming patterns can be quantified studies on single-plastid heterokont algae. In multi- by speed (decrease over time) and rate of change of plastid heterokont algae, it is still unclear whether direction (increase over time). Based on these results, CER is continuous with the nuclear envelope. Since we suggest that computer-assisted motion analysis of nuclear-encoded chloroplast proteins are synthe- the swimming behavior of H. irregularis spores can be sized by ribosomes on the ER membrane, clarifying used to develop bioassays with both ecological and the ER-CER structure in the heterokont algae is im- technological relevance. portant in order to know the targeting pathway of those proteins. We did a detailed ultrastructural ob- 99 servation of endomembrane systems in a multi-plastid A NOVEL BIOFOULING ASSAY USING COM- heterokont alga: Heterosigma akashiwo, and confirmed PUTER-ASSISTED MOTION ANALYSIS OF that the CER membrane was continuous with the ER HINCKSIA IRREGULARIS SPORE SWIMMING membrane. However, unlike the CER membranes in Iken, K. B., Greer, S. P., Amsler, C. D., & other heterokont algae, it seemed to have very few ri- bosome attached. We also performed experiments for McClintock, J. B. protein targeting into canine microsomes using a pre- Department of Biology, University of Alabama at Bir- cursor for a nuclear-encoded chloroplast protein, a mingham, Birmingham AL 35294 USA fucoxanthin-chlorophyll protein (FCP), of H. akashiwo, to see if the protein is targeted to the ER. It dem- Computer-assisted motion analysis of the swimming onstrated that the precursor has a functional signal se- behavior of spores of the brown alga Hincksia irregu- quence for ER targeting, and is co-translationally laris was used in a novel antifouling bioassay. Newly re- translocated into the microsomes. Based on these leased spores were exposed to water soluble com- data, we propose a hypothesis that, in H. akashiwo, nu- pounds of organic and aqueous body wall extracts of clear-encoded chloroplast protein precursors that two sympatric sea stars, Astropecten articulatus and Lu- have been co-translationally inserted into the ER lu- idia clathrata. Changes in the swimming behavior of H. men are sorted in the ER and transported to the chlo- irregularis spores were quantified by changes in speed roplasts through the ER. (decrease at extract exposure) and rate of change of direction (increase at extract exposure). Sea star extracts were tested at natural concentrations (mg ex- 101 tract/g wet weight) and at approximate 10-, 100-, and ENHANCED GROWTH RATES OF THE GERM- 1000-fold dilution. Significant effects (p Յ 0.05) were LINGS OF CYANOBACTERIAL RESTING observed at 1000-fold dilution of the natural concen- SPORES (AKINETES) tration in both extracts of A. articulatus, and at 100- Jameson, I.1, Thompson, P. A.2, & Blackburn, S.1 and 10-fold dilution of the aqueous and organic ex- 1 tract, respectively, in L. clathrata. Germination of CSIRO Division of Marine Research, GPO Box 1538, spores after short time exposure (30 min) to sea star Hobart, Tasmania 7001 Australia; 2School of Aquac- body wall extracts indicates that compounds were not ulture, University of Tasmania, Locked Bag 1-370, toxic but affected spore mobility, a factor that plays an Launceston, Tasmania, 7250 Australia important role during spore settlement. We suggest that this assay is very useful for bioassay-guided frac- In experiments with the toxic cyanobacterium, Ana- tionation of extracts because it is very sensitive and re- baena circinalis, we investigated the nature of cyst for- quires only small amounts of extracts or isolated com- mation and germination under different environmen- pounds. tal conditions (variation in light quality and quantity, 34 PSA ABSTRACTS temperature, nutrient limitation). We consistently amined from three stations in Lake Michigan. Species found that germlings up to about 5 days old had assemblages include chlorophytes, chrysophytes, and greater growth rates than those of vegetative cells diatoms. The diatom flora was particularly abundant. grown under similar saturating irradiance and excess Species composition changed rapidly during storm nutrient conditions in batch culture. Averaging the events, with resting cell forming taxa playing a signifi- results from 4 experiments, the specific growth rate cant role in these modifications. Ephemeral species (KЈ) fell from 1.9 d-1, 24 hours after germination to appeared during the circulation event and decreased 1.17, 1.04, 0.8, and to 0.45 dϪ1 after 48, 72, 120 and once storm activity subsided. Other taxa were able to 144 hours, respectively. This equates to an increase in establish themselves in the phytoplankton community generation time from 0.37 to 1.54 days over this 6 day during the plume events and persisted after storm ac- period. To investigate the implications of these results tivity subsided. Understanding activity during these we modelled two hypothetical populations, A & B, circulation events will lead to a better understanding with an initial akinete or resting cyst concentration of of overall community structure development through- 10/mL each, but with population A having a standard out the year. growth rate of 0.45 and B with the 6 day early enhanced growth rate as determined in our laboratory experiments. The model indicates that population B quickly establishes dominance over population A. In this modeling exercise we have assumed a germina- 103 tion frequency of 100% for both populations but our PHYLOGENETIC ANALYSIS OF THE MARINE laboratory results indicate that even given optimum AND FRESHWATER THALAS-SIOSIROID DIA- germination conditions this factor may vary between TOMS 5% and 90% depending on the age of akinetes and Julius, M. L.1 & Theriot, E. C.2 the conditions experienced during dormancy (senes- 1Center for Great Lakes and Aquatic Sciences, 501 cence). Some conditions that determine germination East University, 726 Dennison, The University of frequency were also investigated. Michigan, Ann Arbor, MI 48109 USA; 2Texas Memo- rial Museum, 2400 Trinity Street, University of Texas, Austin, TX 78705 USA 102 RELATIONSHIP BETWEEN PERIODIC RESUS- The thalassiosiroid centric diatoms are distinguished PENSION EVENTS AND PHYTO-PLANKTON by at least one synapomorphy, the strutted process or BLOOMS IN LAKE MICHIGAN fultoportula. Variously classified as a family (Thalassi- osiraceae) or an order (Thalassiosirales) among cen- Julius, M. L. & Goad, L. tric diatoms, it is generally conceded that the group of Center for Great Lakes and Aquatic Sciences, Univer- several hundred fossil and living species is monophyl- sity of Michigan, 501 East University, Ann Arbor, MI etic as a whole. There are two ecological groups of 48109 USA thalassiosiroids, marine and freshwater. It has been hypothesized, based on an ecletic, non-rigorous, evo- Lake Michigan provides an ideal location for compar- lutionary taxonomy perspective that both the marine ing episodic physical forcing effects (storm events) on and freshwater ecological groups are also monophyl- phytoplankton processes and the more persistent sea- etic, but this hypothesis has never been tested in a rig- sonal variability of phytoplankton communities. This orous framework. Likewise, the freshwater thalassio- is because of the duration and extent of the highly siroid species have been grouped into several genera turbid, recurrent coastal plume (RCP) in the lake and subgenera using an evolutionary taxonomic ap- during the winter/early spring. Although the RCP co- proach, but these hypotheses have not fully been incides with the initiation of the basin wide spring dia- tested using cladistic analysis. Focusing mainly on tom bloom, linkages between the duration and inten- freshwater species, but including at least one repre- sity of the plume and the prominent role of light sentative of each marine genus and one representa- availability in regulating Lake Michigan phytoplank- tive from each of several proposed subgeneric group- ton growth during the spring isothermal period have ings of the genus Thalassiosira, we scored morphological been postulated, but not verified. As such the concur- characters for fossil and living marine and freshwater rent physical and biological events provide a novel op- Thalassiosiraceae to test these hypotheses. Our cladis- portunity to examine how variations in biological rate tic results provide strong support for monophyly for processes, coupled with transport and resuspension the freshwater group, but it seems unlikely that the phenomena associated with the RCP, affect the distri- marine group is monophyletic. The cladistic results butions of organisms, evolution of communities, and are corroborated to greater or lesser degrees by the growth and primary production of Lake Michigan fossil record. The implications for evolution in the phytoplankton. In this study, phytoplankton assem- group and for taxon sampling in molecular studies we blages from pre, post, and active plume events are ex- are conducting will be discussed. PSA ABSTRACTS 35

104 1National Institute for Environmental Studies, PHYLOGENY OF THE BASAL LINEAGES OF Tsukuba, Ibaraki 305, Japan; 2Biological Sciences, STREPTOPHYTA BASED ON RBCL AND ATPB Tsukuba University, Tsukuba, Ibaraki 305, Japan; GENE SEQUENCE DATA 3Faculty of Science, Konan University, Kobe 658-8501 Karol, K. G.1, Delwiche, C. F.1, & McCourt, R. M.2 Japan, 4Bigelow Laboratory for Ocean Sciences, West 1Department of Cell Biology and Molecular Genetics, Boothbay Harbor, ME 04575 USA; 5Biological Sci- H. J. Patterson Hall, University of Maryland, College ences, University of North Carolina-Wilmington, Wilm- Park, MD 20742; 2Department of Botany, Academy of ington, NC 28403 USA; 6Department of Oceanogra- Natural Sciences, 1900 Benjamin Franklin Parkway, phy, University of Hawaii, Honolulu, HI 96822 USA Philadelphia, PA 19103 A new class of algae is proposed for a small group of The streptophytes comprise the Charophyceae sensu unusual chromophytes (ϭheterokont algae). One Mattox and Stewart (a morphologically diverse group novel aspect of these organisms is that cells contain of fresh-water green algae) and the embryophytes large amounts of polyunsaturated fatty acids (41 – (land plants). Several charophycean groups are cur- 67% of fatty acids), with exceptionally high amounts rently recognized. These include the Charales, Co- of EPA (21 – 56% of fatty acids). A second unusual leochaetales, Chlorokybales, Klebsormidiales and character is that, for at least two genera, the mature Zygnemophyceae (Desmidiales and Zygnematales). flagellum (short, smooth flagellum of other chro- Recently, SSU rRNA gene sequence data allied Mesos- mophytes) is dominant, and the immature flagellum tigma viride (Prasinophyceae) with the Streptophyta. (long, hairy flagellum of other chromophytes) lacks Complete chloroplast sequence data, however, placed tripartite hairs and is reduced in size or even absent. Mesostigma sister to all green algae, not with the strep- Carotenoid analysis shows that the class is character- tophytes. Several morphological, ultrastructural and ized by the presence of chlorophylls a and c, fucoxan- biochemical features unite these lineages into a thin, violaxanthin, antheraxanthin, zeaxanthin, and monophyletic group including embryophytes, but evo- ␤-carotene. The 18S rRNA and rbcL gene sequences lutionary relationships among the basal streptophytes show that these organisms form a monophyletic remain ambiguous. To date, numerous studies using group that is supported by very high bootstrap values. SSU rRNA gene sequences have yielded differing phy- The phylogenetic relationships of the Pinguiophyceae logenies with varying degrees of support dependent and other classes are not well resolved, however, the upon taxon sampling and choice of phylogenetic relationships among the chromophytes have always method. Like SSU data, chloroplast DNA sequence been uncertain. The abundance of EPA, known to re- data have been used to examine relationships within duce “bad cholesterol” in humans, suggests this new the Charales, Coleochaetales, Zygnemophyceae and class may be of significant economic importance. embryophytes. Representatives of all basal streptophyte lineages have not been examined using chloro- 106 plast data in a single analysis. Phylogenetic analyses REGENERATION OF PROTOPLASTS FROM were performed using DNA sequences of rbcL (the DISINTEGRATED CELLS OF BRYOPSIS PLU- genes encoding the large subunit of rubisco) and MOSA (DERBESIALES, CHLOROPHYTA) atpB (the beta-subunit of ATPase) to examine rela- Kim, G. H., Klotchkova, T. A., & Kang Y.-M. tionships of basal streptophyte lineages. Preliminary analyses placed the branch leading to Mesostigma as Department of Biology, Kongju National University, the basal lineage in the Streptophyta with Chlorokybus, Kongjushi, Chungnam 314-701, Korea the sole representative of the Chlorokybales, branching next. Klebsormidiales and the enigmatic genus When injured, the protoplasms come out from the Entransia were sister taxa. Sister to these, the Charales, multi-nucleate giant cell of a green alga Bryopsis plu- Coleochaetales, embryophytes and Zygnemophyceae mosa and can generate numerous new cells spontane- formed a monophyletic group with Charales and Co- ously. The cell organelles aggregated rapidly in sea leochaetales sister to each other and this clade sister water and became covered with a gelatinous envelope to the embryophytes. within fifteen minutes. A lipid cell membrane was formed inside the envelope within nine to twelve hours. Cytochemical studies using Nile Red and vari- 105 ous enzymes revealed that the primary envelope is ini- THE PINGUIOPHYCEAE CLASSIS NOVA, tially composed of polysaccharides then becoming a polysaccharide-lipid complex. Fluorescein diacetate CHROMOPHYTE ALGAE PRODUCING LARGE (FDA) staining showed that the primary envelope has AMOUNTS OF OMEGA-3 FATTY ACIDS some characteristics of cell membranes including Kawachi, M.1, Inouye, I.2, Honda, D.3, O’Kelly, semipermeability and selective transport of materials. C. J.4, Bailey, J. C.5, Bidigare, R. R.6, & Andersen, The aggregation of cell organelles appears to be me- R. A.4 diated by two kinds of material; one in vacuolar sap 36 PSA ABSTRACTS and the other on the surface of cell organelles. About Xavier University, Antigonish, Nova Scotia, B2G a thousand new cells were generated from a single dis- 2W5, Canada; 3Department of Zoology & 4Friday integrated branch and forty percent of them eventu- Harbor Laboratories, University of Washington, Friday ally developed into mature plants. Harbor, WA 98250, USA

We examined whether naturally occurring polyphe- 107 nols produced by a brown alga can protect other or- PATTERNS OF RECRUITMENT AND DISTRI- ganisms from ultraviolet radiation. Fragments of Grif- BUTION OF ULVA AND ENTEROMORPHA fithsia pacifica were grown in medium supplemented POPULATIONS IN A KOREAN INTERTIDAL with a seawater extract of Agarum fimbriatum (3% w/v SHORE in seawater for 2 h). Cultures were exposed to cool- Kim, J. H. & Park, S. R. white fluorescent light (7–7.5 ␮Mol photons cmϪ2 Department of Biological Science, Sungkyunkwan Uni- sϪ1) in the presence or absence of 130 to 168 ␮W Ϫ2 Ϫ2 versity, Suwon, 440-746 Korea cm UV-A and 85 to 112 ␮W cm UV-B. Regenerat- ing fragments were scored for five qualitative or quantitative measures of growth. Rhizoid growth was not Patterns of recruitment and abundance of Ulva per- inhibited by the polyphenol extract after ten days. UV tusa and Enteromorpha linza in the three locations on radiation in the absence of polyphenols caused con- the south coast of Korea where green tide frequently siderable cell death and slower growth. Thus, the pres- occurred were investigated with respect to the sub- ence of polyphenols provided protection from UV ra- strate profile, temporal and spatial variations, and diation such that in the highest concentration of their persistence. Artificial substrates (10 to 20 cm) polyphenols (1:1 medium:extract), rhizoid growth in were made of a mixture of a piece of granite rock and UV exposed fragments was approximately 60% as cement on ceramic tiles. These setting plates, repre- great as control plants without both polyphenols and senting different surface texture, were placed hori- UV radiation. Plants exposed to UV radiation in the zontally and vertically along the rocky shoreline, and absence of polyphenol extract showed poor rhizoid replaced every 1 to 2 months. Both populations regeneration and extensive cell death. These experi- showed highly seasonal blooms, with peaks in Octo- ments document the nature of UV-A and UV-B dam- ber, 1998 to February, 1999 and another slight peak age to growing red algae, and provide strong evidence was observed in the fall of 1999 only for Ulva. How- that polyphenols from brown algae may have a role in ever, the winter peak of 1998 did not appeared in the protecting subtidal, benthic algal communities from following year, indicating that a significant year-to- UV radiation. year variation existed. Regarding their settlement onto artificial plates with different roughness, Ulva preferred to settle on the rough surface both in the 109 upper and lower intertidal zone; however, this pattern VERTICAL MIGRATION OF EUGLENA SP. ON only appeared in the upper zone for Enteromorpha. Vertical distribution of the two populations was well THE SAND BANKS OF A NORTH CAROLINA separated; Enteromorpha was more abundant in the up- PIEDMONT STREAM per zone and Ulva in the lower zone. Their seasonal Kingston, M. B. blooms were concomitant with ammonia levels, but Biology Department, Elon College, Elon College, NC occurrence was not well correlated with nitrate and 27244 USA phosphate. The ability of the populations to persist, once blooms occurred, was also distinct; Ulva per- On summer days, visible patches of green appeared sisted ca. twice as long as Enteromorpha, having a on the aerially-exposed sand banks of a small tributary greater impact in the presence of green tide in this of Mays Lake in Burlington, North Carolina. These geographical area. green patches became visible approximately 3 hours after sunrise and disappeared 2 hours prior to sunset. Microscopic examination of sediment samples re- 108 vealed that the appearance of color was due to the up- ULTRAVIOLET ABSORBING SUBSTANCES ward migration of Euglena sp. that attained densities FROM AGARUM FIMBRIATUM (PHAEOPHY- of 2200 cells per square millimeter around solar CEAE) PROTECT GRIFFITHSIA PACIFICA FROM noon. Triplicate sediment cores revealed the pres- UV RADIATION ence of live Euglena cells as deep as 6 cm below the 1 2 3 sediment surface. During the day, over 80% of the Kim, K. Y. , Garbary, D. J. , Hoffmann, J. , & population was located between the surface and a 4 Duggins D. depth of 2 mm. During the night, 75% of the popula- 1Department of Oceanography and Institute of Marine tion was found between 2 and 6 cm below the surface. Sciences, Chonnam National University, Kwangju Artificially darkening the sediment surface during the 500-757, Korea; 2Department of Biology, St. Francis day stimulated downward migration of the popula- PSA ABSTRACTS 37 tion. Controlled experiments with neutral density fil- 111 ters indicated that the number of cells on the sedi- SEASONAL VARIATIONS IN PHYTOPLANK- ment surface was directly related to incident irradiance. TON COMMUNITIES OF AN EPHEMERAL The results of these experiments on Euglena sp. living POND SYSTEM IN SOUTHEASTERN VIR- on the banks of a freshwater stream in central North Carolina will be contrasted with those of previous ex- GINIA periments conducted on Euglena proxima living on the Kokolis, M. R. intertidal sand flats of the Newport River estuary in Department of Biological Sciences, Old Dominion Uni- coastal North Carolina. versity, Norfolk, VA 23529USA

The Grafton Ponds Natural Area is a 151 hectare preserve in York County, Virginia, approximately 56km north of the City of Norfolk. The preserve contains over 40 ephemeral ponds. These ponds which are 110 filled seasonally by precipitation and groundwater dis- INFLUENCE OF ANTHROPOGENIC POLLU- charge, are typically wet from late fall through late TION ON MACROPHYTOBENTHOS OF THE spring or early summer. Pond size varies from 0.1 to 2 AVACHA BAY (SOUTHEAST KAMCHATKA, ha, and depths range from 4 cm to 3 meters. The first RUSSIA) phase of this study was to examine the physical and Klotchkova, N. G.1 & Berezovskaya, V. A.2 chemical characteristics of five of these ponds, includ- 1Laboratory of Phycology, Kamchatka Institute of Ecol- ing pond size and depth, inundation period, water ogy & Nature Management, Russian Academy of Sci- temperature, pH, and phosphate and ammonium ences, Petropavlovsk-Kamchatsky, 683000 Russia; concentrations. The second phase, which is currently 2 underway, is to examine the phytoplankton assem- Departament of Chemistry & Ecology, Kamchatka blages, relating differences in the phytoplankton pop- State Technical University, Petropavlovsk-Kamchatsky, ulations to the varying physical and chemical charac- 683003 Russia teristics of the ponds. To date, analysis indicates Chlorophytes and Cyanobacteria as dominant groups Most industrial and agricultural enterprises of the Ka- in the winter and spring with diatoms becoming more mchatsky district are situated along the coast of the abundant in the late summer and fall. Periodic Di- Avacha Bay and its river drainage. Intensive water pol- noflagellate blooms also occur. Analysis also indicates lution resulted in extreme deterioration of the bay’s rapid turnover of species from month to month. ecology. The destruction of macrophytobenthos under the influence of pollution was investigated. Mate- 112 rials were regularly collected at the same sampling FIELD STUDY OF ALGAL RECRUITMENT BY sites in different seasons of the year from 1988 up to CLEARING EXPERIMENT IN PING CHAU, 1999. Analysis of our data allowed us to determine di- rections of long-term changes of species composition HONG KONG SAR, CHINA and macrophytobenthos structure, speed of degrada- Kong, S. L. & Ang, P. O. tion of different types of vegetational communities Department of Biology, The Chinese University of Hong and reasons for all these processes. The Avacha Bay’s Kong, Shatin, N.T., Hong Kong SAR, China flora consisted of more than 160 species up to 1970s, including species belonged to 104 genera, 47 families, Recruitment, the entry of new individuals into a popu- 23 orders, 3 divisions (30 Chlorophyta, 48 Phaeo- lation, was investigated by a clearing experiment phyta, 82 Rhodophyta). Flora of the internal part of along the shore of A Ma Wan (AMW) in Ping Chau, the bay differed from that of the bay’s mouth and Hong Kong SAR, China. Two types of clearing, with consisted of 143 and 146 species, respectively. Pres- all the existing vegetation removed (cleared) and with ently, the whole flora of the bay (internal partϩ the top 2 to three mm of the rock surface removed throat) includes only 94 species. Along the urban (hammered), were carried out monthly in AMW from coast 18 poly- and mesosaprobious species are found November 1997 to June 1999. Observations were only. They are characterized by small sizes, low pro- made one month after clearing and on a monthly ba- ductivity and short life cycles. Most of them are sis thereafter. The number of algal species present on ephemeral with a primitive morphology. The respon- the cleared areas and their percentage cover were re- sive reaction of algae to pollution resulted in de- corded. The experimental results showed that more creases in size and weight of the thalli, and appear- algal species were recruited during March and April ance of anomalies of development. Laminaria in 1998 (nϭ10) but in 1999, the number of species bongardiana was used as a bioindicator. The changes was found higher in February and March (nϭ8). Spe- of weight and sizes of its plants allow us to determine cies richness dropped after May (more obvious in degree of the pollution in different parts of the coast 1998), indicating that recruitment greatly declined in of the Avacha Bay. summer. A tuft complex composed of several filamen- 38 PSA ABSTRACTS tous algal species dominated over the others in all 1Wrigley Institute of Environmental Studies, University clearing areas (coverage mostly over 90%) but re- of Southern California, P.O. Box 5069, Avalon, Cali- cruits of Caulerpa peltata, Colpomenia sinuosa, Enteromor- fornia, 90704-5069 USA; 2Marine Sciences Research pha sp., Hypnea charoides, Padina spp., Sargassum sp., Centre, State University of New York, Stony Brook, NY, Spyridia filamentosa, Ulva sp., etc. also were observed 11794-5000 USA during the study period. Generally, there were no significant differences in terms of species richness and Nitrogen assimilation and allocation strategies were composition of the recruits between the two treat- compared in polar macroalgae from environments ments (cleared vs. hammered) as well as with the con- with similar near-freezing temperatures and low trols. This implied that algae in AMW were more annual irradiance but differing dissolved inorganic ni- likely to be recruited de novo from elsewhere rather trogen (DIN) regimes. The antarctic endemic, Himan- than regenerated from remnants of the previous tothallus grandifolius, experiences high nitrate con- year’s growth. centrations year-round and occasionally high, but variable, ammonium levels. H. grandifolius cannot 113 store nitrogen or maintain growth under periods of NUCLEAR RIBOSOMAL DNA PHYLOGENY low N-supply. The arctic endemic, Laminaria solidun- OF HALIMEDALES REVEALS SEVERAL POLY- gula, is exposed to seasonal fluctuations in DIN, with PHYLETIC GENERA N-limitation occurring during the summer. L. solidun- Kooistra, W. H. C. F.1 & Hillis, L. W.2 gula showed “storage-specialist” characteristics of ni- 1S.T.R.I., Unit 09948, APO AA 34002-0948 USA & trate uptake, with high Vmax allowing this species to Department of Marine Biology, Biological Center, Post- take advantage of seasonally elevated nitrate concen- box 14, 9750 AA Haren, The Netherlands; 220 Brooks trations to accumulate large organic and inorganic N- Rd., Woods Hole, Ma 02543 USA reserves. H. grandifolius had a high Vmax for ammonium, allowing the alga to utilize pulses of this nutrient. In the presence of both DIN forms, nitrate up- Halimedales (Chlorophyta) are widely distributed in take was significantly reduced in both species. reefs and lagoons throughout the tropics and sub- Furthermore, H. grandifolius and L. solidungula dem- tropics. One genus, Chlorodesmis, consists of simple, onstrated significantly reduced uptake and assimila- branching siphons that persist into the mature sexual tion of nitrate during short-term and prolonged peri- phase. In most other genera, only the juvenile stages ods of darkness, while ammonium uptake and exhibit such simple anatomy. Their mature, often-cal- assimilation were relatively unaffected by light. Al- cified thalli possess complex siphonal anatomy and though preferential uptake of ammonium, particu- differentiation depending on the location in the thal- larly in the dark, allows both species to conserve en- lus. We obtained a nuclear ribosomal DNA phylogeny ergy in their cold, low-light environments, the encompassing many genera in order to unravel the antarctic species, which does not have the additional evolution of this complexity. Results pinpoint Caul- problem of N-limitation, showed stronger energy con- erpa as outgroup to a clade with all other genera in- serving traits. Nitrogen assimilation characteristics of cluded in this study. The first dichotomy separates the arctic species appeared to balance energy conser- Halimeda from the remaining genera. Distinct gamet- vation with the need to minimize N-limitation in an angial anatomy defines these two principal clades. environment that alternates between low light and Within the remainder, Tydemania and its sister Flabel- low N availability. lia are nearest neighbors to a clade containing Rhipo- cephalus, Udotea, Penicillus and Chlorodesmis. The latter three genera are polyphyletic. Therefore, character 115 states of thallus superstructure defining these genera EXPRESSION PATTERNS OF THREE PUTA- appear to be homoplasies. Chlorodesmis represents a TIVE SEXUAL-SPECIFIC GENES IN THE CEN- case of neoteny where the juvenile stage persists into TRIC DIATOM THALASSIOSIRA WEISSFLOGII reproductive maturity. We will evaluate which mor- Koumandou, V. & Armbrust, E. V. phological characters do change state in agreement Marine Molecular Biotechnology Laboratory, School of with the molecular phylogeny and can, therefore, serve as diagnostic characters for a more natural clas- Oceanography, University of Washington, Seattle, WA sification. 98195

114 An intriguing feature of the diatom life cycle is that sexual reproduction not only generates genetic diver- NITROGEN ASSIMILATION AND ALLOCA- sity but also controls cell size. Very little is known, TION STRATEGIES OF POLAR SEAWEEDS however, about either the frequency or the potential FROM DIFFERING NUTRIENT ENVIRON- ramifications of sexual events in field populations, MENTS due in large part to the difficulties associated with rec- Korb, R. E.1 & Gerard, V. A.2 ognizing sexual stages. Our approach has been to PSA ABSTRACTS 39 identify genes involved in the diatom sexual cycle, grown at 20Њ C (only about 2% of gametophytes). The with the goal of developing molecular probes to de- Conchocelis stage, however, need not limit mariculture termine when and where sexual reproduction occurs. operations; once Conchocelis cultures are established, We are investigating the expression pattern of three they can be maintained over the long-term as ready genes identified in a sexual reproduction screen. The sources of spores for net seeding. Sig1, Sig2 and Sig3 genes comprise a gene family, and encode proteins with strong sequence homology to extracellular matrix proteins. We have hypothesized 117 that the Sig proteins are necessary for sperm/egg rec- NEW GENERA OF FRESHWATER CRYPTO- ognition. Using RT-PCR, we have shown that tran- MONADS FROM COLORADO scription of the Sig genes is highly upregulated dur- 1 1 2 3 ing the early stages of the sexual cycle, before any Kugrens, P. , Aguiar, R. , Clay, B. L. & Lee, R. E. 1 morphological changes are apparent. The three Department of Biology,Colorado State University, Fort genes show significant differences in the exact timing Collins, CO 80523USA; 2 Biology Department, Uni- and levels of expression, suggesting different roles for versity of Massachusetts, Amherst, MA 01003 USA each member of the gene family. We are now employ- Massa of 3Department of Anatomy and Neurobiology, ing quantitative RT-PCR to study their relative tran- Colorado State University, Fort Collins, CO 80523 scription levels in more detail. We are also using anti- USA bodies made against a recombinant version of the Sig2 protein to look at protein expression levels be- Electron microscopic examinations of numerous iso- fore and after sexual induction, and to determine lates from Colorado lakes and reservoirs have re- where the Sig2 protein localizes in the cell. vealed several new genera and species. Based on the furrow/gullet variations and the structure of the peri- 116 plast, four new genera are proposed. These new genera and their characteristics are as follows. The first PRELIMINARY EVALUATION OF THE BIO- genus has a furrow without a gullet, and it has oval REMEDIATION POTENTIAL OF PORPHYRA: periplast plates. There are two chloroplasts per cell PHOTOSYNTHETIC PRODUCTION BY and two nucleomorphs located anterior to the chloro- BLADES AND CONCHOCELIS plasts in the periplastidial compartment. Pyrenoids Kraemer, G. P.1 & Yarish, C.1 are lacking. Chloroplasts contain phycoerythrin 566. 1Department of Environmental Sciences, Purchase Col- The second genus is similar in shape and structure to lege, State University of New York, Purchase, NY Plagioselmis, but it has small rectangular plates rather 10577 USA; 2Department of Ecology and Evolutionary than hexagonal plates. There is one dorsal chloro- Biology, University of Connecticut, Stamford, CT plast per cell, with a single stalked pyrenoid, which is not traversed by thylakoids and associated with two 06901 USA starch plates. The nucleomorph is posterior to the pyrenoid and is located between the nucleus and Given their rapid growth and nutrient assimilation pyrenoid. Chloroplasts contain phycoerythrin 566. rates, Porphyra spp. are good candidates for bioreme- The third genus lacks a gullet and furrow and has an diation. The production potential of two northeast inner periplast sheet. Cells have two chloroplasts with- U.S. Porphyra species currently in culture (P. purpurea out pyrenoids, and the chloroplasts contain phyco- and P. umbilicalis) was evaluated by measuring rates of erythrin 566. The nucleomorphs are located in the photosynthesis (as O2 evolution) of samples grown at anterior portion of the plastidial compartment. The 20Њ C. Gametophytes of P. umbilicalis photosynthe- fourth genus is blue-green in color, it lacks a furrow/ sized at rates that were 80% higher than those of P. gullet, and the internal and surface periplast compo- purpurea over 5–20Њ C at both sub-saturating and satu- nents consist of hexagonal plates. Cells have a large Ϫ2 rating irradiances (37 and 289 ␮mol photons m pyrenoid that protrudes ventrally into the cytoplasm Ϫ1 s ). Porphyra umbilicalis was both more efficient at low and is traversed by numerous paired thylakoids. The irradiances (higher alpha) and had a higher Pmax than nucleomorph is situated lateral to the pyrenoid. Chlo- Ϫ1 Ϫ1 did P. purpurea (23.0 vs. 15.6 ␮mol O2 g DW min ), roplasts contain phycocyanin 645. This cryptomonad suggesting that P. umbilicalis is a better choice for mass was previously identified as Chroomonas pochmanni, culture where self-shading may be severe. The photo- and it is mixotrophic. synthesis-irradiance relationship for the Conchocelis stage of P. purpurea was also examined. Tufts of filaments, grown at 10, 15, and 20Њ C, were assayed at 118 growth temperatures at irradiances ranging from 0– 315 ␮mol photons mϪ2 sϪ1. Tufts were slightly more GENETIC STRUCTURE VARIABILITY OF productive at 15Њ than at 10Њ C, but only ca. 4–6% as KELP ALARIA MARGINATA OVER SPACE AND productive as gametophytes. Maximum rates of net TIME photosynthesis were reduced by 66–74% in tufts Kusumo, H. T.1 & Druehl, L. D.2 40 PSA ABSTRACTS

1Department of Ecology & Evolution University of Chi- phate that is accessible to alkaline phosphatase and cago, 1101 E. 57th St., Chicago, IL 60637; subsequently to T4 polynucleotide kinase in vitro. It is 2Department of Biological Sciences, Simon Fraser Uni- also possible to modify the 3’-end with terminal deox- versity, Burnaby, BC V5A 1S6, Canada & Bamfield ynucleotidyl transferase (TdT) for homopolymeric Marine Station, Bamfield, BC V0R 1B0, Canada tailing. Poly-(C) tailing of native molecules promotes their annealing to poly-(G) tailed vectors, for cloning of the terminal domains. An initial library of 14 TdT The genetic variability of Alaria marginata Postels & clones (10 unique) indicates that short (11–28 bp) di- Ruprecht was investigated spatially and seasonally us- rect repeats occur near the termini of the plasmids. ing the finger printing technique of amplified frag- Shorter (4–6 bp) inverted repeats at the very ends ment length polymorphism (AFLP). Using 206 score- may lead to terminal foldbacks that might serve to able bands generated by one primer pair, individual protect the termini. plants that were separated by as little as a few decimeters to Ͼ100 km could be distinguished, and followed an isolation-by-distance model. Genetic similarity 120 ranged from 76% for patches (a few decimeters in diameter), to 71% for individual kelp stands (15 m LIFE ON THE EDGE: STRESS SURVIVAL across) and 67% for a group of stands separated by ADAPTATIONS IN SOUTHERN LIMIT MAC- 185 km. Greater genetic similarity of patches oc- ROCYSTIS PYRIFERA POPULATIONS curred at the wave-sheltered site than at wave-exposed Ladah, L. B. site. The influence of wave to genetic variability and Universidad Autonoma de Baja California, Instituto the ability to predict gene flow on small stretch of de Investigaciones Oceanologicas Apdo. post # 453, beach were discussed. In one stand, genetic similari- Ensenada, Baja California, Mexico ties were markedly different between seasons. This seasonal pattern may be the result of different age In spite of subtropical temperatures often occurring groups dominating the sampled stands over time. The at the Macrocystis pyrifera distributional southern limit genetic structure of A. marginata comprises local scale in the Northern Hemisphere in Baja California, Mex- (patch and within stand) heterogeneity and larger ico, the population has been successful at surviving scale (between stands) homogeneity. and recovering from disturbance. To explore the physiological characteristics of southern limit M. py- 119 rifera, microscopic and macroscopic phases of south- MOLECULAR ANALYSES OF LINEAR CHLO- ern limit plants were tested for stress tolerance and ROPLAST PLASMIDS FROM ERNODESMIS compared to northern plant responses in three exper- VERTICILLATA iments. In spore development experiments, under constant temperature and nitrate stress treatments, La Claire, J. W., II & Wang, J. spores from the southern-limit population survived Section of Molecular Cell & Developmental Biology, higher temperatures, had greater survivorship, and School of Biological Sciences (A6700), University of were able to complete their life cycle at higher tem- Texas at Austin, TX 78712 USA peratures and lower nitrate concentrations than northern population spores. During stress-recovery Ernodesmis verticillata contains novel, linear plasmid- treatments, where all microscopic stages were tested like DNA molecules in its chloroplasts, whose func- for recovery after stress shock exposure (temperature, tion remains unclear. Their molecular architecture is nitrate and light stress), 96% of all haploid treatments putatively a “hairpin,” wherein every molecule con- showed some regrowth during recovery; haploid sur- sists of a long inverted repeat folded back on itself. vival was not significantly affected by spore population Thus, each molecule is composed of a terminal (telo- origin, light, or nitrate. However, only 26% of diploid meric) domain, a central inverted repeat, and a treatments showed regrowth and diploid survival was “loop” domain. Cloning strategies have been devised significantly affected by spore population origin; only for characterizing the terminal and loop regions, the southern limit spores recovered after stress treat- since they might contain landmark features like repli- ment exposure. In juvenile transplant experiments, cation origins. Polymerase chain reaction (PCR) was under all conditions, juvenile plants originating from used to amplify loop domains of native molecules, the southern-limit had higher tissue nitrogen content, and ligation of the PCR products with commercial greater frond addition rates, and higher photosyn- cloning vectors initially yielded 11 clones. So far, no thetic efficiency than northern plants, particularly at recognizable sequences have turned up in the loop higher temperatures. The physiological differences domains of the molecules. Unlike what has been re- observed for the southern limit plants versus those ported for most linear plasmids, we have been unable from the north contributes to our understanding of to verify that any proteins are associated with either how the southern limit plants can survive in an envi- the 5Ј- or 3Ј-ends of the Ernodesmis plasmids. In fact, ronment that might otherwise be considered extreme the 5Ј-end of each molecule contains a terminal phos- for the species. PSA ABSTRACTS 41

121 arctica species. Chlorophyll a/d ratio ranged from 6 ACCUMULATION OF DOMOIC ACID BY THE to 21123. The fraction of species of red algae contain- COASTAL DIATOM PSEUDO-NITZSCHIA MUL- ing chlorophyll d was higher in samples collected in TISERIES: A POSSIBLE COPPER COMPLEX- October (36 out of 36), than those collected in June (12 out of 29) or March (4 out of 22). Chlorophyll d ATION STRATEGY was not detected in any of the brown or green mac- Ladizinsky, N. L. & Smith, G. J. roalgae analyzed. In vivo absorption spectra of Gelid- Moss Landing Marine Labs, 8272 Moss Landing ium sp. were collected, and resolution of these spectra Road, Moss Landing, CA 95039, USA by fourth derivative resulted an absorption maximum at 687 nm due to chlorophyll a, and at 719 nm due to Domoic acid (DA) is a neurotoxic amino acid pro- chlorophyll d. Extracted pigment of Gelidium sp. in duced by several members of the diatom genus 90% acetone had an absorption maximum of 664 nm, Pseudo-nitzschia. Trophic transfer of DA up the food and a smaller absorption peak at 692 nm. Fluores- chain has been implicated in the deaths of 100’s of cence emission and excitation spectra resulted in a marine birds and marine mammals along the central maximum of 699 nm and 447 nm, respectively. The California Coast. The physiological function of DA in emission peak wavelength of 699 and an absorption Pseudo-nitzschia spp. has not been defined, although peak longer than that of chlorophyll a (699 nm com- some evidence indicates that elevated metal concen- pared to 664 nm) suggest chlorophyll d may serve as a trations can induce DA accumulation (Subba RAO et light-harvesting pigment in photosynthesis. al., 1998, P.S.Z.N. Mar. Ecol. 19:31). Although Califor- nia coastal waters have experienced a decline in several heavy metals from 1977–1990, copper concentra- 123 tions have increased by as much as 25% (Stephenson, FLUID SHEAR-STIMULATED DINOFLAGEL- M. D. & Leonard, G. H., 1994, Mar. Poll. Bull. 28:148). LATE BIOLUMINESCENCE Many algae produce chelators, including amino acids, 1 2 2ϩ Latz, M. I. & Rohr, J. in response to toxic [Cu ] (Wu et al. 1998, J. Phycol. 1 34: 113). Domoic acid, a tricarboxylic acid, has 4 func- Scripps Institution of Oceanography, University of tional groups that may readily form chelation com- California San Diego, La Jolla, CA 92093 USA; 2 plexes with transition metals like copper. Copper en- SPAWAR Systems Center, San Diego, CA 92152- richment experiments indicate that while Cu2ϩ is 5000 USA toxic to Pseudo-nitzschia multiseries at total [Cu] greater than 16.1␮M (pCu 6.0), intracellular DA accumula- Bioluminescence studies provide insight into the tion increases up to this point with no decline in properties of water motion that are stimulatory to growth rates relative to cultures grown in standard en- flow-sensitive organisms such as dinoflagellates, the riched seawater. These data suggest that DA may be most common sources of near-surface oceanic biolu- accumulated by P. multiseries to mitigate the toxicity of minescence. Previous laboratory studies employing elevated [Cu2ϩ]. Chemiluminescence will be used to steady flows have characterized the luminescent re- quantify the binding affinity (expressed as conditional sponse of dinoflagellates in terms of shear stress. In stability constants, Kc) of DA for Cu2ϩ. Defining the the present study, computational and experimental Cu-DA dose response relationship in Pseudo-nitzschia approaches were used to investigate the contributions can facilitate prediction of future toxic bloom events. of shear and acceleration to cells responding in a laminar converging flow field, where regions of high ac- 122 celeration and shear are spatially separated. Flow- THE UBIQUITOUS PRESENCE OF CHLORO- stimulated flashes by the dinoflagellates Lingulodinium polyedrum and Ceratocorys horrida were used as a near- PHYLL D IN RED ALGAE FROM THE MON- instantaneous monitor of cell response. By combining TEREY PENINSULA video analysis of flash trajectories with computational Landráu, M. E. & Welschmeyer, N. A. methods, the location of each stimulated cell was de- Moss Landing Marine Laboratories, 8272 Moss Land- termined and flow parameters at that location were ing Road, Moss Landing, CA 95039 USA calculated. Based on several criteria, shear stress was considered the flow parameter most stimulatory to The presence of chlorophyll d in red algae has been a cells. For both dinoflagellates species and for all flow subject of great controversy, however, only a few stud- rates, essentially all cells responded downstream near ies have been devoted to this subject, and evidence for the wall where shear stress levels were maximal, and its existence has been inconsistent. Here we report on levels of acceleration and extensional stress were as results of a survey of 56 species of red macroalgae much as two orders of magnitude less than locations from central California, 3 species from Baja California away from the wall. Minimum shear stress levels at the Sur, Mexico, and 2 species from Cape Evans, Antarc- cell positions were consistent with response thresh- tica. Chlorophyll d was detected in 48 of the Califor- olds based on previous studies. Bioluminescence is an nia species, 1 of the Mexico species, and 1 of the Ant- excellent tool for examining how organisms respond 42 PSA ABSTRACTS to flow at the small temporal and spatial scales rele- algal classes. For example, members of the class Dino- vant to planktonic organisms. phyceae display sterol compositions ranging from as few as two (cholesterol and dinosterol in Alexandrium 124 tamarense) to as many as twelve in certain Heterocapsa NOSTOCACEAN MACRO-MORPHOGENESIS species. Certain of these are 4-methyl sterols rarely Lazaroff, N.1,2 & Eichelberger, H. H.2 found in other classes of algae. The ability to use ste- 1 2 rol biomarkers to distinguish certain dinoflagellates Micro-Nostix, Vestal, NY 13850-1516 USA; Dept of such as the toxic species Gymnodinium breve, responsi- Biological Sciences, State University of New York at ble for red tide events in the Gulf of Mexico, from Binghamton, NY 13902-6000 USA other species within the same class would be of con- siderable scientific and economic value. Gymnodinium A poorly understood feature of nostocacean growth breve has been shown by others to possess two princi- and development is the formation of ordered macro- pal novel sterols, (24S)-4a-methylergosta-8(14), 22- scopic structures from microscopic cells, trichomes, dien-3b-ol (ED) and its 27-nor derivative (NED), not and filaments. Using macro-photography, time-lapse previously known to be present in other dinoflagel- micro-cinematography, light and electron microscopy lates. Characterization of free and esterified sterols of Nostoc species in pure culture, it has been possible from laboratory cultures of G. breve and of samples to demonstrate how motility, adhesion and aggrega- from a recent bloom in the Gulf of Mexico has con- tion of photo-induced hormogonia result in macro- firmed the predominance of these two sterols. This morphogenesis of dendroid forms. Red-light induced has prompted a study of the sterol signatures of more hormogonia from synchronized cultures aggregate than 30 dinoflagellates. ED and NED were shown also rapidly on agar as tight flowing streams, in patterns re- to be the primary sterols of the closely related dinoflagel- sponsive to the direction and quality of incident light. lates G. mikimotoi and G. galatheanum. They are also Unlike the even textured cell surfaces of heterocys- found as minor components of the more complex ste- tous filaments, the cell walls of swarming hormogonia rol profiles of other members of the Gymnodinium-Peri- are covered with a striate mucoid layer containing pili dinium-Prorocentrum (GPP) taxonomic group. The attached to cells of adjacent hormogonia. During dif- more widespread distribution of this sterol pattern is ferentiation to an aseriate phase, cell wall fusions consistent with the known close relationship between occur and a gelatinous matrix forms around the G. breve and G. mikimotoi. enlarging sub-globose cells. Liquid suspensions of hormogonia aggregate in a solid mass following the net centripetal movement of interlaced loops of 126 curved hormogonia attached by adhesive pili. In dark- SPECIES PHYLOGENY OF COSMARIUM AND ness or dim white light, compressed hormogonial ag- STAURASTRUM (DESMIDIACEAE) BASED ON gregates form erect tree-like (dendroid) macro-struc- RBCL SEQUENCES tures by photo-tactic reversal of streaming motility. Lee, O.-M.1, McCourt, R. M.2, Nam, M.1 & Karol, Hormogonia within the aggregates re-organize into K. G.3 streams that push upward into the light, forming 1Department of Biology, Kyonggi University, Suwon- structured, positively phototropic protuberances, sev- city 442-760, Kyonggi-do, Korea; 2Department of Bot- eral millimeters in length. Under weak illumination, any, Academy of Natural Sciences, 1900 Benjamin the structures become branched with crowns of wav- 3 ing hormogonia. The dendroid morphology is stabi- Franklin Parkway, Philadelphia, PA 19103; Department lized by deposit of gelatinous material derived from of Cell Biology and Molecular Genetics, H. J. Patterson successive cycles of cell-filament development, libera- Hall, University of Maryland, College Park, MD tion of heterocysts and formation of dormant cells 20742 and trichomes. Cosmarium and Staurastrum are the two most diverse 125 genera of placoderm desmids (Family Desmidiaceae), STEROLS AS BIOMARKERS IN GYMNODIN- with approximately 1100 and 800 species, respectively. IUM BREVE: DISTRIBUTION IN DINO- Phylogenetic analysis of relationships of species has FLAGELLATES been extremely difficult. In a monograph of North 1 2 American placoderm desmids, Prescott et al. de- Leblond, J. D. & Chapman, P. J. scribed early phylogenetic work that concluded Stau- 1 National Research Council Postdoctoral Associate; rastrum to be polyphyletic and certainly polymorphic. 2US EPA (NHEERL), Gulf Ecology Division, 1 Sabine Likewise, Cosmarium has also been viewed as polyphyl- Island Dr., Gulf Breeze, FL 32561 USA etic, and a number of workers have proposed splitting these genera. The classical view of West and West The sterol composition of marine microalgae has grouped species within each genus into two divisions been shown to be a chemotaxonomic property poten- and 6–8 sections based on wall features and semicell tially of value in distinguishing members of different shape. We sequenced rbcL from 18 species of Cosmar- PSA ABSTRACTS 43 ium (2 divisions, 7 sections) and 12 species of Stauras- action of cyclic AMP is mediated by cyclic AMP-depen- trum (2 divisions and 7 sections) and performed a dent protein kinase (PKA). Efforts to identify PKA in phylogenetic analysis (parsimony, maximum likeli- dinoflagellates have met with mixed success in previ- hood, bootstrap) using other placoderm desmids and ous studies. In Amphidinium operculatum, we have iden- Zygnematales as outgroups. The results exhibit little tified the presence of cAMP, and observed cell cycle support for the monophyly of sections or divisions of inhibition by the cAMP pathway inhibitor, isobutyl the two genera. Furthermore, although there is sup- methylxanthine, suggesting the presence of a eukary- port for the monophyly of clades within each genus, otic cAMP pathway. However, crude lysates of A. oper- there is also support for a separate clade containing culatum failed to show in vitro kinase activity toward species from both genera. kemptide, a specific substrate of mammalian PKA. This may reflect the presence of unidentified low molecular weight inhibitors, because when cell lysates 127 were fractionated by gel filtration chromatography, MEASUREMENT OF MICROALGAL CELL cAMP dependent kinase activity was identified. The VOLUME BY FLOW CYTOMETRY molecular weight of this PKA was 66 kDa, much smaller than bovine PKA (250 kDa), but similar to Leighfield, T. A. & Van Dolah, F. M. that reported in the diatom Cylindrotheca (78 kDa). Marine Biotoxins Program, Center for Coastal Envi- Current work is focusing on characterization of sub- ronmental Health and Biomolecular Research, NOAA, unit structure of the PKA of A. operculatum, as com- National Ocean Service, Charleston, SC 29412 USA pared with bovine PKA.

Single cell analysis by flow cytometry is a powerful tool that has been employed to identify many different 129 characteristics of phytoplankton populations. Cell vol- RELATIVE TOLERANCE OF MAT-FORMING ume is an important physiological component of many cellular processes. We have used a Coulter EP- ALGAE TO COPPER AND ITS IMPLICA- ICS XL flow cytometer to measure cell volume in the TIONS spheroid dinoflagellate Amphidinium operculatum as a Lembi, C. A. function of forward scatter. Cell volume measure- Department of Botany and Plant Pathology, Purdue ments of this alga were quantified as equivalent spher- University, W. Lafayette, IN 47907 USA ical diameters from a standard curve obtained with la- tex beads of known diameter. This parameter was The major method for algae control in the U.S. is the used to monitor cell diameter throughout the cell di- application of copper. Certain groups of phytoplank- vision cycle. In log phase cultures, A. operculatum ton, such as the green algae, are known to be more showed increasing cell volumes throughout the light tolerant to copper than groups such as the cyanobac- phase and a maximum cell volume concurrent with teria. Through experience, commercial applicators the onset of cell division late in the light phase. The suggest that mat-forming algae also differ in their sus- maximum equivalent spherical diameter measured 14 ceptibility to copper, but to this point, data to support ␮m, while the minimum equivalent spherical diame- these observations have not been available. Labora- ter was 10 ␮m that occurred late in the dark phase. tory studies in which unialgal cultures of mat-forming Stationary phase cultures of A. operculatum did not ex- algae were exposed to a range of copper concentra- hibit oscillating cell volumes throughout the diel cy- tions show a clear progression in copper tolerance. cle. Chemical inhibition of the cell cycle using 100 The EC50 values (concentration of copper in mg Cu ␮M olomoucine diminished cell volume changes dur- LϪ1 that results in 50% reduction of biomass) were ing the light phase. These results suggest a coupling less than 0.003 (Spirogyra, Oedogonium), approximately of size control to the cell division cycle. 0.050 (Hydrodictyon, Pithophora, Rhizoclonium), and greater than 0.200 (Oscillatoria). These data are important to us in the midwest because Oscillatoria is be- 128 coming a more frequent component of mat-forming IDENTIFICATION OF A CYCLIC AMP-DEPEN- algae infestations. The Oscillatoria infestations are DENT PROTEIN KINASE IN THE DINO- caused by at least five different species, each of which FLAGELLATE AMPHIDINIUM OPERCULATUM is very tolerant to copper. Circumstantial evidence suggests that the increasing frequency of this mat- Leighfield, T. A. & Van Dolah, F. M. forming cyanobacterium is due to elimination of Marine Biotoxins Program, Center for Coastal Envi- more sensitive genera (such as Spirogyra or Rhizoclo- ronmental Health and Biomolecular Research, NOAA, nium) with heavy copper dosing. In addition to con- National Ocean Service, Charleston, SC 29412 USA cerns often expressed about copper use, such as buildup in the sediments, toxicity to invertebrates, Cyclic AMP is an important signaling molecule in and possible (although not well verified) resistance of both prokaryotes and eukaryotes. In eukaryotes, the cyanobacteria, another compelling reason to seek al- 44 PSA ABSTRACTS ternative approaches to copper is the buildup of cop- one of which corresponds to the Delesserioideae, one per-tolerant mat-forming algae. to a narrowly circumscribed Nitophylloideae, and the third to a new subfamily comprising the remainder of 130 the Nitophylloideae sensu Kylin. Belonging to the Delesserioideae are an expanded Hemineura group PHENOLOGY OF SCINAIA LATIFRONS (NEM- that includes Hemineura, Patulophycus, Marionella, ALIALES; RHODOPHYTA) IN THE SOUTH- Laingia, Botryocarpa and possibly Pseudophycodrys, a WESTERN GULF OF CALIFORNIA, MEXICO Caloglossa group, a Hypoglossum group that includes León-Cisneros, K. & Riosmena-Rodriguez, R. Hypoglossum, Branchioglossum, Bartoniella, Zellera, Phity- Herbario Ficológico, Mar. Biol. Dept., UABCS, Ap. morphora, and Chauviniella, a Delesseria group with Postal 19-B, La Paz B.C.S. 23080 México Delesseria, Membranoptera and possibly Grinnellia (but not Apoglossum) and most southern hemisphere Scinaia latifrons Howe is one of the main species in species of Delesseria which are properly placed in Para- rhodolith beds between 30 and 90 feet; however, little glossum J. Agardh 1898. The revised Nitophylloideae known about the morphological changes of this spe- contains Nitophyllum, Valeriemaya, Polyneuropsis, Caloni- cies. Consequently, we investigated the phenological tophyllum and also Martensia and Opephyllum. The un- changes of the species at San Lorenzo channel from named subfamily includes the Phycodrys group with December 1998 to December 1999 (based on bi- Phycodrys and Polyneura, the Cryptopleura group with weekly sampling during the first 6 months and species placed in Cryptopleura, Hymenena, Acrosorium monthly sampling during the last part of the study). and Botryoglossum, the Myriogrammeae with Myrio- The gametophyte phase of the species is present from gramme and Haraldiophyllum, and the Schizoserideae December to late May and the sporophyte potentially with Schizoseris, Neuroglossum, Drachiella, Abroteia, and is present the rest of the year. The peak of the devel- South American species of Platyclinia. This research opment occurs in April and reproduction occurs in promotes the correlation of molecular and morpho- small size plants with two cohorts in the period. This logical phylogenies with biogeographic hypotheses species presents an allometric growth pattern due to for the family. the lack of correlation between size and width of the plant or branching patterns. Our data suggest that 132 temperature and light control the development of the PHYLOGENY OF THE EUGLENOPHYTES: plant. Furthermore, we found the spermatagonial ANALYSIS USING SSU RDNA AND ULTRA- structure in the same thallus as the female/carpo- STRUCTURAL CHARACTERS sporophyte plant indicating that this species is mo- Linton, E. W. & Triemer, R. E. noeious (contrary to what was considered previously). Division of Life Science, Rutgers University, Piscat- This suggests that some taxonomic problems are away, NJ 08854 USA present in this species in relation with S. cottoni. The use of both molecular and morphological data to 131 determine relationships among the euglenoids is vital PHYLOGENETIC AND TAXONOMIC REAS- for a complete understanding of their phylogeny, and SESSMENT OF THE DELESSERIACEAE (CER- the development of an accurate taxonomy. Analyses AMIALES, RHODOPHYTA) BASED ON TWO of the SSU (18S) rDNA from 12 euglenoid genera MOLECULAR DATA SETS have resulted in tree topologies that are in agreement Lin, S. M.1, Fredericq, S.1, & Hommersand, M.2 with many defining morphological characters. The euglenoid lineage is formed by phagotrophic eugle- 1Department of Biology, University of Louisiana at 2 noids at its base, followed by the divergence of pho- Lafayette, Lafayette LA 70504 USA; Department of totrophs that in-turn gave rise to osmotrophs. The Biology, University of North Carolina at Chapel Hill, photosynthetic lineage is anchored by euglenoids Chapel Hill NC 27599 USA with two emergent flagella, Eutreptia and Eutreptiella, while the remainder of the lineage is composed of eu- The current system of classification of the Delesseri- glenoids with a single emergent flagellum. Among the aceae rests largely on Kylin’s treatment which encom- photosynthetic euglenoids with a single emergent fla- pass the subfamilies Delesserioideae with five gellum those that secrete mucilaginous stalks, Colacium, ‘Groups’ and Nitophylloideae with six ‘Groups’. In or form a lorica, Trachelomonas and Strombomonas, are this study we test the Kylin system based on phyloge- closely associated. The remaining photosynthetic gen- netic analyses inferred from two molecular data sets era Euglena, Phacus, and Lepocinclis are intermixed and morphological evidence. A total of 145 delesseri- with each other and the osmotrophic genera Astasia, acean taxa worldwide were sequenced for chloroplast- and Khawkinea. Hence, they are not monophyletic, encoded rbcL, and 82 taxa for the nuclear-encoded sensu Hennig. To reinforce molecular phylogenies, a large subunit ribosomal RNA gene (LSU). Three robust morphological character database is necessary. large clades are identified in the combined data sets, For taxa with complex internal structures complete PSA ABSTRACTS 45 serial reconstruction is required. Serial reconstruc- in their environment. When exposed to chemicals re- tion of the flagellar and feeding apparatuses in Ploeo- leased from the grazer Ceriodaphnia, unicellular S. tia costata illustrate this necessity. Originally described obliquus populations were rapidly transformed into co- as having both an MTR (Type I) and a Type II feeding lonial ones. The morphological response appeared apparatus, reconstruction has shown P. costata to have strongly correlated with the amount of algae grazed a single, Type II, feeding apparatus. Moreover, the upon by the Ceriodaphnia. The induced S. obliquus col- Type II now appears to be an autapomorphy for Ploeo- onies were protected against grazing, as were large tia species, while euglenoid feeding apparatuses, in spined Scenedesmus, whereas unicellular S. obliquus and toto, appear to form a continuum of structural types. spined Scenedesmus remained vulnerable to grazing by Ceriodaphnia. Growth rates of unicellular and induced- colonial S. obliquus populations were identical. How- 133 ever, sinking rates were significantly higher for the in- PHENOLOGY OF PORPHYRA PENDULA duced-colonial S. obliquus. Hence, the phenomenon (BANGIALES; RHODOPHYTA) IN THE of grazer-induced colony formation in S. obliquus can SOUTHWESTERN GULF OF CALIFORNIA, be interpreted as an inducible defense at the expense of higher sinking losses. MEXICO López-Vivas, J. M. & Riosmena-Rodriguez, R. Herbario Ficológico, Mar. Biol. Dept., UABCS, Ap. Postal 19-B, La Paz B.C.S. 23080 México 135 Porphyra pendula Dawson is an endemic species of the THE TYPE SPECIES OF CERAMIUM (RHODO- mid-intertidial zone in the Gulf of California. Based PHYTA), CERAMIUM VIRGATUM ROTH: TYPI- on surveys from the Phycological Herbarium of UABCS FICATION AND PHYLOGENY since 1994, we found an extensive population of this Maggs, C. A., McIvor, L. M., Evan, C. M. & species in Punta Coyote, south of La Paz. Here, we assess the phenology of the gametophyte phase from De- Stanhope, M. J. cember of 1998 to June of 1999 with visits every 2 School of Biology and Biochemistry, Queen’s University weeks. Our results show significant temporal and spa- of Belfast, Belfast BT9 7BL, United Kingdom tial changes in length and width of the plant, with some quadrants displaying two peaks in development The type species of Ceramium is Ceramium virgatum (January and March) and other quadrants with a Roth (1797, Cat. Bot I: 148, pl. VIII, fig. 1). This has peak only in January. A significant correlation existed been treated as a probable synonym of Ceramium nod- between length and width of the blade and is linked ulosum (Lightfoot) Ducluzeau, one of the species for- with plant maturation, observations which strongly sup- merly confused under the illegitimate name Ceramium port the isometric growth rate of the species. No dif- rubrum (Hudson) C. Agardh. However, in 1996 Silva ferences between exposed and protected areas were showed that C. nodulosum (Lightfoot) Ducluzeau is a observed suggesting stronger differences between later homonym of C. nodulosum de Candolle 1805, and quadrants. Differences plants in length and in color advocated conserving C. rubrum with a neotype. As an existed between male and female plants; the males alternative to this, we investigated whether the name were smaller and yellow and females/carposporo- C. virgatum might be available for this species. The lec- phyte were larger and red-purple. Most of the thalli totype of C. virgatum is Roth’s illustration of a much- were reproducing during the study, with a greater branched, fully corticate, Ceramium specimen from proportion of females than males (ca. 2:1). Our re- Eckwarden, North Sea, which could represent any sults suggest that the morphological changes in this member of the ‘C. rubrum’ group. We obtained mate- species may be related with temperature and day rial resembling Roth’s, from the North Sea island of length. Helgoland, as a potential epitype. Its rbcL sequence was aligned with sequences of all C. rubrum-like species in the British Isles, i.e. C. secundatum, C. botryocar- 134 pum, C. pallidum and ‘C. nodulosum’. The Helgoland GRAZER-INDUCED DEFENSE IN SCENEDES- material was clearly conspecific with ‘C. nodulosum’ MUS OBLIQUUS (CHLOROPHYCAEA) from Ireland (0.08% divergence). We therefore suggest that the name C. virgatum Roth should be em- Lürling, M. ployed for this species. Phylogenetic analyses of these Department of Food Web Studies, Center for Limnology, sequences aligned with various representatives of the Netherlands Institute for Ecology, Nieuwersluis 3631 tribe Ceramieae, placed the North Atlantic C. rubrum- AC 6, The Netherlands like species in two well-supported clades. In one of these, C. virgatum is basal to C. secundatum and C. botry- The non-spiny Scenedesmus obliquus may express con- ocarpum. The other clade consists of C. pallidum and a siderable phenotypic plasticity in response to changes partly ecorticate species resembling C. diaphanum. 46 PSA ABSTRACTS

136 and had abundant chloroplast ribosomes. The leuco- INTER-FAMILY USE OF MICROSATELLITE plast of N. alba also had a multi-membrane envelope, MARKERS IN LAMINARIALES: THE EXPERI- chloroplast ribosomes, and a genome that encodes ENCE BETWEEN LAMINARIA DIGITATA AND plastid specific proteins. This suggested that the plastid of N. alba may still possess the biochemical func- LESSONIA SPP. tions of the chloroplast, aside from photosynthesis. 1 1 1 Martínez, E. A. , Cardenas, L. , Figueroa, C. , To determine whether plastidial fatty acid biosynthe- Vidal, R.1, & Billot, C.2 sis occurred in N. alba, the response of the two dia- 1Departamento de Ecologia, Facultad de Ciencias Bio- toms to the compound thiolactomycin was compared. logicas, Pontificia Universidad Catolica de Chile, Thiolactomycin has been shown to effect keto-acyl- Casilla 114-D, Santiago, Chile; 2Universidade do Al- ACP-synthases, and specifically inhibits the plastidial garve Campus de Gambelas P-8000 FARO, Portugal fatty acid biosynthetic pathway. While growth of N. alba was not impacted by thiolactomycin as in N. lae- Among the co-dominant molecular markers, micro- vis, neutral lipid accumulation and fatty acid composi- satellite loci have a number of advantages in population was impacted by thiolactomycin in both organ- tion genetic studies. However, the different methods isms. These findings suggest that the plastidial fatty to hunt these markers are expensive, time consuming, acid biosynthetic pathway does exist in the leucoplast and they require sophisticated laboratory equipment. of N. alba, although it lacks photosynthetic capacity. Using in one species the microsatellites primers originally described for another one saves time and re- duces costs. Examples in the literature revealed that 138 microsatellites described for Gracilaria gracilis from France have not worked for other members of the SYSTEMATICS AND PHYLOGEOGRAPHY OF Gracilariales. The results were not very promising, at THE INVASIVE RED ALGA, POLYSIPHONIA least for Gracilaria chilensis from Chile. In this study, a HARVEYI number of microsatellite loci described for Laminaria McIvor, L. M.1, Maggs, C. A.1, & Stanhope, M. J.2 digitata (Laminariaceae) from France were amplified 1School of Biology and Biochemistry, Department of Sci- and sequenced in two Lessonia (Lessoniaceae) species ence and Agriculture, Medical Biology Center, The from Chile. Preliminary results show a partial conser- Queens University of Belfast, Belfast, United Kingdom; vation of both, flanking and tandem repeat regions. 2SmithKline Beecham Pharmaceuticals, South College- Some polymorphism has also been detected in Lesso- ville Road, UP1345, Collegeville, PA 19426 USA nia spp. The higher molecular affinity (conservation of primer sites) observed in species belonging to different families of brown algae, respect to that ob- Polysiphonia harveyi Bailey was first described from served among species of the same genus in the red Connecticut in 1848 and morphologically similar spe- algae, is surprising. Such a result is strikingly counter- cies, such as P. japonica and P. strictissima, have subse- intuitive when observing the morphological disparity quently been described many times from different lo- among the Laminariales, respect to the similarity ob- calities such as Japan and New Zealand, placing the served in the Gracilariales. It also reminds one of an taxonomy and nomenclature of this morphologically earlier discussion by Gary Saunders about “When a variable species in confusion. Polysiphonia harveyi is re- family is not a family”. garded as an alien in the British Isles and the north- eastern North Atlantic and is reported to be spreading rapidly. The first confirmed collection of P. harveyi 137 from the British Isles was in 1908; the source of the PLASTID FATTY ACID BIOSYNTHESIS IN British introduction remains unknown. In conjunc- THE DIATOMS NITZSCHIA ALBA AND NITZS- tion with breeding data, rbcL sequences for samples of P. harveyi, P. strictissima, P. japonica and P. akkeshiensis CHIA LAEVIS collected from New Zealand, Atlantic and Pacific McGinnis, K. M. & Sommerfeld, M. R. North America, Japan and Europe, reveal that P. har- Department of Plant Biology, Arizona State University, veyi, P. japonica and P. akkeshiensis constitute a single Tempe, AZ 85287 USA biological species. The correct name for this is P. harveyi, whilst P. strictissima from New Zealand is a sibling The role of the plastid in fatty acid biosynthesis in the species, distinct from P. harveyi. The center of genetic non-photosynthetic diatom Nitzschia alba was studied diversity of P. harveyi is in Japan. The original source and compared to that in the photosynthetic, closely of the introduced P. harveyi in the British Isles, Eu- related Nitzschia laevis. Transmission electron micros- rope and Nova Scotia appears to be Hokkaido, Japan. copy was used to analyze structural features of the Separate introductions from a single source popula- plastid that may be relevant to biochemical function. tion into New Zealand and Pacific and Atlantic North Typical of a photosynthetic diatom, N. laevis had a America from Honshu, Japan, apparently have oc- chloroplast envelope composed of four membranes, curred. PSA ABSTRACTS 47

139 vestigations suggest that the Chlorococcum-like mor- THE TYCHOPELAGIC DIATOM, PARALIA phology has evolved in at least three lineages. Further- SULCATA, AS PALEOINDICATOR SPECIES IN more, these data suggest that the ability to grow COASTAL MARINE ENVIRONMENTS optimally at low pH has independently evolved in several lineages. McQuoid, M. R. Department of Marine Botany, Göteborg University, Box 461, SE-405 30 Göteborg, Sweden 141 COMPARING RESPIRATORY (ETS) ACTIV- Paralia sulcata is a diatom commonly found in both ITY OF BACTERIA ATTACHED TO PHY- the plankton and benthos of coastal environments. TOPLANKTON AND FREELY SUSPENDED IN This species is heavily silicified and, thus preserves SURROUNDING SEAWATER well in sedimentary records making it a potentially Milbrandt, E. C. & Shapiro, L. S. useful paleoindicator species. However, its tychope- Oregon Institute of Marine Biology, P.O. Box 5389, lagic nature and its association with a wide range of Charleston, OR 97420 USA environmental conditions have made detailed paleo- ecological interpretations complicated. High-resolu- We conducted investigated respiratory (ETS) activity tion sediment records from coastal fjords in both Can- of bacteria attached to phytoplankton and living free ada and Sweden show variations in the abundance in surrounding seawater collected from coastal waters and morphology of P. sulcata that provide evidence of at Charleston, Oregon, USA. We hypothesized that changes in benthic habitat distribution and surface the surface of a phytoplankton cell provides a habitat water properties in the fjords on timescales of decades that permits enhanced metabolic activity in attached to centuries. These studies suggest that P. sulcata can bacteria. In order to test this hypothesis, the number be an important paleoindicator species when inter- of bacteria that reduce 5-Cyano-2,3-di-tolyl tetrazo- pretations are made in the context of its complex lium chloride (CTC) were compared to the total ecology. number of bacteria, assessed by the nucleic acid stain, 4Ј,6-diamidino-2-phenylindole (DAPI). Two-hour incu- 140 bations with the CTC dye and subsequent staining allowed for direct viewing of the position and the num- PHYLOGENY OF THE GENUS CHLOROCOC- ber of ETS active versus inactive bacteria in each CUM: A STUDY OF 18S AND 26S rRNA GENE sample. We found that the percentage of active bacte- SEQUENCES ria attached to the phytoplankton cells’ surface (42%) Michalopulos, J. U., Buchheim, J. A. & Buchheim, was 10 times that of bacteria freely suspended in the M. A. surrounding seawater (4%). Previous investigations of Department of Biological Science, The University of ETS activity of freely suspended bacteria found that Tulsa, 600 South College Avenue, Tulsa, OK 74104 1% to 8% are actively respiring while non-living parti- USA cle associated bacteria showed that 20 to 35% of bacteria are actively respiring. Our results suggest that bacteria in coastal waters are substrate limited, and Phylogenetic studies of 18S rRNA gene sequence data the extracellular products of photosynthesis may be support an alliance of the green algal genus, Chlorococ- more important than is generally realized. The sur- cum, with other chlamydomonadalean taxa that pro- faces of phytoplankton cell surfaces may provide habi- duce walled, motile stages. Moreover, these phyloge- tat and substrates for a disproportionate share of bac- netic studies indicate that Chlorococcum is not terial production in coastal waters. monophyletic, but rather falls into two distinct lineages. However, these molecular phylogenetic studies were based on only a few taxa in a genus that exhibits 142 marked habitat diversity. In particular, numerous spe- SEASONAL GROWTH AND NUTRIENT ECO- cies of Chlorococcum currently in the UTEX collection PHYSIOLOGY OF ECKLONIA RADIATA FROM have been isolated from naturally acidic environ- DOUBTFUL SOUND, FIORDLAND, NEW ments. Except for a few groups (e.g., desmids), acidic ZEALAND environments are not generally regarded as niches for 1 1 2 widespread exploitation by green algae. A new investi- Miller, S. M. , Hurd, C. L & Wing, S. 1 gation of diversity among species of Chlorococcum in- Department of Botany, University of Otago, Dunedin, cluded broader taxon and data sampling schemes. Se- New Zealand; 2Department of Marine Science, Univer- quence data from both the nuclear-encoded 18S and sity of Otago, Dunedin, New Zealand 26S rRNA genes were collected from 17 different UTEX and SAG isolates of Chlorococcum. In addition, The kelp, Ecklonia radiata, dominates the sublittoral controlled growth experiments at varying acidity (pH zone within the Doubtful Sound complex. Doubtful 5.0, 6.0, and 8.0) were conducted. Results of these in- Sound is one of a series of fourteen fiords indenting 48 PSA ABSTRACTS the southwestern coast of the South Island, New work provided evidence that more thermotolerant lin- Zealand. A feature of these fiords is the freshwater eages of Synechococcus evolved from less thermotoler- layer that resides atop the salt water, creating a ant ancestors. The extension of the thermal limit in unique marine environment. Mature sporophytes these bacteria was correlated with a reduction in ther- were collected from three sites (two outer sites to- mal niche breadth, which may have implications for wards the coastline and one site within the fiord) over the geographic distributions of these organisms. This a fourteen-month period (October 1998 to December study illustrates the utility of using phylogenetic com- 1999). Growth rates, measured using the hole punch parative methods to investigate how evolutionary pro- technique, were greatest in spring at all three sites. cesses have shaped historical patterns of ecological di- The nutrient eco-physiology of mature E. radiata was versification in microorganisms. investigated by measuring inorganic nitrogen (NOϪ3 and NHϩ4) uptake rates at eight concentrations (2–64 Ϫ3 ϩ4 ␮M). Soluble tissue nitrogen (NO and NH ) and 144 tissue carbon:nitrogen (C:N) ratios were also determined. At all sites, E. radiata showed higher uptake RELATING PHYTOPLANKTON BIOMASS AND rates for ammonium than for nitrate. In winter, solu- PRODUCTION TO EPISODIC PHYSICAL ble tissue nitrogen was lower at the two outer sites FORCING IN SOUTHEASTERN LAKE MICHI- compared to the inner site, while in summer, levels at GAN all sites were similar but had decreased from the win- Millie, D. F.1, Fahnenstiel, G. L.2, Lohrenz, S. E.3, ter values. C:N ratios greater than 20 were observed at & Schofield, O.4 all sites, increasing in summer to a peak in autumn, 1USDA-ARS., c/o Mote Marine Laboratory, 1600 Ken suggesting E. radiata may be nitrogen limited, particu- Thompson Parkway, Sarasota, FL 34236 USA; larly in late summer. Environmental parameters (pho- 2NOAA-GLERL, Lake Michigan Field Station, ton flux density, water temperature, rainfall and Muskegon, MI 49441USA; 3Department of Marine wind) were measured, as was sea water velocity Science, University of Southern Mississippi, Stennis around the primary blade of E. radiata, and multivari- 4 ate correlations used to determine which (if any) en- Space Center, MS 39529 USA; Institute of Marine & vironmental parameter exerted greatest influence on Coastal Sciences, Rutgers University, New Brunswick, eco-physiological parameters accessed. NJ 08901 USA

Spatial and temporal dynamics in phytoplankton re- 143 flect of the combined effects of the physical and THE EVOLUTION OF THERMOTOLERANCE chemical environments and associated biological re- IN HOT SPRING CYANOBACTERIA OF THE sponses. Although alterations in phytoplankton are GENUS SYNECHOCOCCUS well-documented for a variety of lentic waters, the ex- Miller, S. R.1 & Castenholz, R. W.2 act linkages between environmental forcing and phy- 1 toplankton assemblages remain poorly understood M/S 239-4, National Aeronautics and Space Admin- (particularly for coastal systems). A recurrent sedi- istration, Ames Research Center, Moffett Field, CA ment resuspension event occurs every late winter/ 2 94035 USA; Department of Biology, University of Ore- early spring in southeastern Lake Michigan, often ex- gon, Eugene, OR 97403 USA tending greater than ten km in width and 300 km in length. Inherently, such a large-scale and dramatic The extension of ecological tolerance limits may be physical process would be thought to dramatically in- an important mechanism by which microorganisms fluence phytoplankton assemblages; however, link- adapt to novel environments, but it may come at the ages between the turbidity plume and phytoplankton evolutionary cost of reduced performance under an- assemblages have been postulated, but never verified. cestral conditions. We combined a comparative physi- As such, the episodic nature of the plume provided an ological approach with phylogenetic analyses to study opportunity to examine the effects of a short-term the evolution of thermotolerance in hot spring cyano- physical forcing event on coastal phytoplankton in re- bacteria of the genus Synechococcus. Among the twenty lation to more persistent, seasonal meteorological laboratory clones of Synechococcus isolated from collec- forcing. Lake phytoplankton assemblages within and tions made along an Oregon hot spring thermal gra- outside of the RCP were examined during the spring dient, four different 16S ribosomal RNA gene se- isothermal period from 1998 to 2000. Here, we de- quences were identified. Phylogenies constructed scribe results from the 1998 and 1999 field seasons using these sequence data indicated that the clones characterizing the distribution of phytoplankton bio- were polyphyletic but also that three of the four se- mass and composition within and adjacent to the RCP quence groups formed a clade. Differences in ther- and their relationship to particulate and dissolved con- motolerance were observed for clones with different stituents. In addition, the spatial and temporal pat- 16S rRNA gene sequences, and comparison of these terns in production and photosynthetic characteris- physiological differences within a phylogenetic frame- tics of the phytoplankton community are examined. PSA ABSTRACTS 49

145 Recent phylogenetic studies of tetrasporalean exem- ALGAL BIOREMEDIATION OF THE BERKE- plars using 18S rDNA revealed the extent of diversity LEY PIT LAKE among taxa in this non-monophyletic group (Booton Mitman, G. G. et al. 1998). In particular, two distinct tetrasporalean lineages were identified; one group allied with chlamy- Department of Biological Sciences-Montana Tech of domonadalean taxa and the other group comprising The University of Montana taxa now placed in a separate order, the Chaetopeltid- ales. Using these observations as a framework, a new Ongoing research is unraveling the intricacies of the investigation of diversity among a broader sampling microbial ecology of the Berkeley Pit Lake System, of putative tetrasporalean genera (e.g. Asterococcus, with ever increasing information becoming available Chloranomala, Chlorophysema, Gloeocystis, Gloeodendron, regarding the diversity of Algae, Protistans, Fungi and Palmella, Paulschulzia, Physocytium, Schizochlamys and Bacteria that inhabit this mine waste site. Defining the Tetraspora) was undertaken. Phylogenetic studies of both baseline community structure has been the first step 18S and 26S rDNA were compared with ultrastructural not only toward understanding the interactions of the investigations of vegetative cells. Molecular phyloge- different groups of organisms, but also toward assess- netic analyses corroborate the earlier 18S rDNA results, ing any improvement in biodiversity within the biotic but also reveal additional diversity. The new data raise community. Now that this first step has begun, some doubts regarding the monophyly of two genera, Palmella of these extremophiles, specifically algae, that have and Tetraspora. The new data also link two enigmatic been isolated from the Berkeley Pit Lake System are green algal genera, Physocytium and Heterochlamydomo- being used as a potential solution for bioremediation. nas, in a long-branch lineage within the Chlamy- The specific objectives of this research are fivefold: 1) domonadales. Another enigmatic genus, Schizochlamys, To evaluate the bioremediative potential of our four is allied with Bracteacoccus in the Sphaeropleales. Lastly, most rapidly growing species: (Chromulina freiburgensis Chloranomala is resolved as an ally of Paulschulzia, Tet- Dofl., Chlorella ellipsoidea Gerneck, Chlorella vulgaris raspora sp., and the green flagellate, Lobomonas. Com- Beyerinck and Chlamydomonas acidophilla Negoro) in parison of pyrenoid ultrastructure generally supports Berkeley Pit Lake System Water with the additions of the molecular phylogenetic analyses, suggesting that NaNO3 and NaPO4 by using an experimental matrix. this non-molecular character will be a useful marker This matrix will be used to estimate the minimum nu- for broad phylogenetic studies of chlamydomonad- trient concentrations that would be necessary to alean taxa. (Supported by NSF grant, DEB 9726588) achieve the maximum growth of algae and maximum bioremediation of the Berkeley Pit Lake System. 2) To determine which combination of nutrients will stimulate growth of the best bioremediator of our 147 four isolated species in natural Berkeley Pit Lake Sys- CHEMICALLY INDUCED ECDYSIS AND ISO- tem waters. In other words, what nutrient combina- LATION OF NUCLEI FROM THE DINO- tion will give the best bioremediator a competitive edge over the other species. If time permits, different FLAGELLATES GONYAULAX POLYEDRA AND species may be grown in combination to determine if GONYAULAX TAMERENSIS there are synergistic effects (protocooperation) be- Morris, R. L., & Rizzo, P. J. tween/among species. 3) To determine a tempera- Department of Biology, Texas A & M University, Col- ture profile for these four species in order to deter- lege Station, TX 77843 USA mine their optimal growth temperature in Berkeley Pit Lake System water. 4) To continue to isolate or- Armored dinoflagellates such as Gonyaulax sp. are not ganisms from the Berkeley Pit Lake System and deter- good candidates for isolation of intact clean nuclei, mine their bioremediative potential. 5) Monitor algal due to difficulty in breaking the cells. Previously, isola- and bacterial counts from a profile of Pit Lake System tion of nuclei from Gonyaulax was achieved using vig- waters. The results to date will be presented for this orous cell disruption by ultrasonication (Rizzo & conference. Hastings, unpublished observations). A detergent method for production of spheroplasts from Gon- yaulax was published some time ago (Adamich & 146 Sweeney, 1976), but was not reproducible (Rizzo & DIVERSITY AMONG TETRASPORALEAN TAXA: Hastings, Morris & Rizzo, unpublished observations). We describe here a modification of the method de- EVIDENCE FROM ULTRASTRUCTURE AND scribed by Adamich & Sweeney that is highly repro- MOLECULES ducible. Ecdysis and production of intact dinoflagel- Moreland, A., Buchheim, M. A. & Buchheim, J. A. late spheroplasts with a yield of virtually 100% within Department of Biological Science, The University of 5 minutes, has been achieved through the use of an- Tulsa, 600 South College Avenue, Tulsa, OK 74104 ionic and nonionic detergents in hypotonic buffers. USA This method of ecdysis followed by a gentle sphero- 50 PSA ABSTRACTS plast breakage in a hypotonic buffer allowed the 1Centre for Scientific Research of the Slovene Academy release of nuclei for later biochemical analysis with of Science & Arts, Gosposka 13, SI-1000 Ljubljana, minimal damage or breakage. The nuclei are subse- Slovenia; 2University of Ljubljana, Faculty of Chemis- quently purified by centrifugation in a Ficoll discon- try & Chemical Technology, Murnikova 8, SI-1000 tinuous gradient. Ljubljana, Slovenia

148 The ephemeral green alga Ulva rigida C. Ag. is com- STRUCTURAL AND SEQUENCE SIGNA- mon in polluted and eutrophicated sites of the north- TURES OF NUCLEAR SSU RRNA DEFINE ern Adriatic. Its tolerance and responses to the com- TAXONOMIC LEVELS WITHIN THE RHODO- bined effects of excess macronutrients (nitrates, phosphates) and metals (Mn, Co, Zn) that are essen- PHYTA 1 2 2 tial micronutrients were studied in vitro regarding Müller, K. M. Sheath, R. G. , Sherwood, A. R. , growth expressions, survival, elemental composition 1 1 Madabusi, L. V. , Cannone, J. J. , Subashchandran, (N, C, P), and metal accumulation. Plants belonging S.1, Lin, N.1 & Gutell, R. R.1 to vernal/estival and autumnal populations were com- 1Institute of Cellular and Molecular Biology, Univer- pared. Excess nutrients were applied together with sity of Texas at Austin, Austin, TX 78712; 2Dean’s the single metals. Nitrate and phosphate were used Office and Department of Botany, University of separately and in a dual combination. In control sam- Guelph, Guelph, ON N1G 2W1 Canada ples that lacked metals, it was obvious that plants belonging to vernal and estival populations grew better Over 400 nuclear SSU rRNA sequences representing in phosphate than in nitrate enriched media and that all orders of the Rhodophyta were aligned and ana- the opposite was true for autumnal plants. The pres- lyzed using comparative sequence analysis. Numerous ence of metals altered the responses of U. rigida to ex- nucleotide positions and structural elements were cess nutrients. In some of the samples a relationship found that delineated various taxonomic groups. The between Mn accumulation and growth was indicated, 1245 region (E. coli numbering) contained a loop that Mn promoting growth. Metal accumulation was differed in size between two conserved helices and greater in the autumnal than in the vernal and estival clearly separated the Florideophyceae [3 nt (Ͼ95% of plants, being the highest for Mn and lowest for Zn. A 268 sequences)], Bangiales [13 to 14 nt (100% of 116 comparison between experimental series of different sequences)] and remaining Bangiophyceae including duration revealed that the metal accumulation in- the Cryptophyta nucleomorphs [four to eight nt creases time-dependently for Mn and Co. The N and (100% of 32 sequences)]. In addition, members of P content of the plants followed the nutrient enrich- the Thoreaceae were found to have additional helices ment of the media. Autumnal plants accumulated in the 650 and 1139 region of which a corresponding more N and P than vernal and estival ones. It was obvi- structure was not present in any other red algal SSU ous that the presence of metals influences the nitro- rRNA gene sequence. Base-pair and nucleotide signa- gen uptake of U. rigida, in the sequence Mn-Co-Zn. tures differentiated the Bangiales, Florideophyceae, The presence of Mn promotes nitrogen uptake and Bangiophyceae (not including Bangiales) and Hilden- that of Zn is inhibitory. brandiales at three levels of comparison: within the Rhodophyta (Ͼ400 sequences), the Eukaryota (not 150 including Rhodophyta; Ͼ1300 sequences) and three kingdom (Archaea, Bacteria, 2 organelles, Eukaryota; SEASONAL SUCCESSION OF PHYTOPLANK- Ͼ7000 sequences). For example, all members of the TON IN LAKE PRINCE, SUFFOLK, VIRGINIA: Hildenbrandiales have a change in the base-pair PRELIMINARY REPORT 512:539 that is a region of functional importance. Se- Muscio, C.M. quences from the Eukaryota, Archaea, Bacteria and Department of Biological Sciences, Old Dominion Uni- two organelles have a C:G or a U:A in this position versity, Norfolk, VA, 23529 USA whereas the Hildenbrandiales have a C:A pair. This analysis raises the possibility of utilizing structural fea- Lake Prince is a reservoir lake that provides the re- tures of nuclear SSU rRNA and sequence signatures gion with drinking water, recreational boating, and to support and delineate phylogenetic clades within fishing. The Virginia Department of Game and In- the Rhodophyta. land Fisheries has an interest in the quantity and quality of phytoplankton production in the lake, especially 149 regarding the health of fish populations. Another concern in this reservoir is oxygen availability, and COMBINED EFFECTS OF MACRONUTRI- aerators have been installed in the main body of the ENTS AND METALS ON THE ADRIATIC lake. A year-long examination of the phytoplankton GREEN ALGA ULVA RIGIDA C.AG. community structure is being conducted. Duplicate Munda, I. M.1 & Veber, M.2 surface water samples are collected monthly from PSA ABSTRACTS 51 three stations, along with physical and chemical base- ily reflect phylogenetic relationships revealed by se- line data. Community structure and dominance are quence analyses: convergence in character states is being examined with regard to the physical and obscuring relationships. In the course of our work we chemical parameters, as well as seasonal climate have discovered that four species, originally described changes. Cyanobacteria and Cryptophytes are the on the basis of traditional morphological and anatom- dominant spring flora. Diatoms and Chrysophytes are ical characters as Porphyra or Bangia, are more closely sub-dominant populations. related to members of the order Erythropeltidales than to the Bangiales. These results are challenging 151 us to consider new ways of describing and defining these organisms. We are finding convergence in char- PRELIMINARY STUDIES OF SEASONALITY, acter states, not only within Porphyra sens. lat. But ECOLOGY, AND SPECIES COMPOSITION spanning both the Bangiales and Erythropeltidales, OF ULVOID ALGAL BLOOMS IN WASHING- which confounds both taxonomic distinctions and TON STATE also phylogenetic hypotheses based on morphology Nelson, T. A. and anatomy. This confusion could be countered ef- Blakely Island Field Station, Seattle Pacific University, fectively by the inclusion of molecular sequence data Seattle, WA 98119-1997, USA based on vouchered or type material in descriptions of taxa in the orders Bangiales and Erythropeltidales. Blooms of green macroalgae can devastate important This would allow conclusive identification of collected finfish and shellfish habitats. Ulvaria obscura, a rela- material by appropriate molecular tests, which are tively unstudied green alga, is a major contributor to quicker and more direct identification tools than, for these blooms in the San Juan Islands, Washington example, using characters drawn from the growth of State, USA. The biomass and productivity of this and these organisms under controlled culture conditions. other ulvoid algae were measured seasonally for two years. Experiments comparing the growth rates, re- 153 sponses to desiccation, photoacclimation, and grazer THE PHYLOGENY OF CAULERPA BASED ON preference of U. obscura and Ulva fenestrata were con- RDNA INTERNAL TRANSCRIBED SPACER ducted. Ulvaria blooms tended to occur in the sub- SEQUENCES tidal while Ulva blooms were often intertidal. Both Nemeth, S., Mai, T. T., & Zechman, F. W. genera bloomed between late June and September. Department of Biology, California State University, Despite their superficial similarity, Ulvaria and Ulva Fresno, CA 93740 USA display markedly different physiological and ecological responses. Ulva was capable of faster growth, had higher rates of photosynthesis, and was more desicca- Phylogenetic hypotheses for the pantropical marine tion tolerant than Ulvaria. Ulvaria, however, appears green algal genus, Caulerpa, were inferred based on to be more resistant to grazing than Ulva. analyses of nuclear-encoded rDNA internal transcribed spacer (ITS) sequences. Results of these analyses were used to assess the correspondence between 152 rDNA phylogeny and traditional sectional taxonomy, CONFUSING CONVERGENT MORPHOLO- to identify synapomorphic morphological characters GIES: DIVERSITY AND DIFFICULTIES IN (including assimilator morphology and chloroplast NEW ZEALAND ERYTHROPELTIDALES AND ultrastructure), and to examine marine biogeo- BANGIALES graphic hypotheses for the genus. Ribosomal DNA Nelson, W. A.1, Broom, J. E.2, & Farr, T. J.1 ITS sequences were aligned for thirty-three species and intraspecific taxa of Caulerpa. Results indicate 1Museum of New Zealand Te Papa Tongarewa, PO 2 limited correspondence between phylogeny and sec- Box 467, Wellington, New Zealand; Department of tional taxonomy for the genus, (e.g., the sections Fili- Biochemistry, University of Otago, PO Box 56, Dune- coideae and Sedoideae were not monophyletic). In din, New Zealand contrast, chloroplast morphology could be mapped to the tree topology with limited homoplasy. Pantropical An examination of New Zealand species of Porphyra isolates of the filicoidean species, Caulerpa sertulario- and Bangia has led to the discovery of unexpectedly ides and Caulerpa mexicana each formed monophyletic high diversity. In excess of 30 species of Porphyra and 5 groups. Caulerpa reyesii was included as a derived species of Bangia can be distinguished, based on 18S taxon within the Caulerpa taxifolia clade, suggesting rDNA sequence data. It is possible to develop a work- that these species were conspecific and affirmed the able taxonomic framework to distinguish species of lack of correspondence between phylogeny and Porphyra found within this geographic region using a assimilator morphology. Isolates and various intra- range of characters (morphological, anatomical, bio- specific taxa of Caulerpa racemosa did not form a chemical, physiological, life history characteristics). monophyletic group. Instead, these taxa formed a However, the taxonomic distinctions do not necessar- heterogeneous assemblage with other sedoidean and 52 PSA ABSTRACTS filicoidean taxa. Within the C. sertularioides clade, Car- ences, University of Iowa, 239 Biology Building, Iowa ibbean and Atlantic isolates formed a basal paraphyl- City, Iowa 52242 USA etic group, whereas eastern and western Pacific isolates formed a more derived monophyletic group. The Rhodophyta are composed of the subclasses Ban- Therefore, these results are not consistent with an giophycidae and Florideophycidae. Two evolution- Indo-West Pacific origin of this species. arily interesting features of the Bangiophycidae are: (1) they are the ancestral pool from which the more 154 morphologically complex taxa in the Florideophy- FINE STRUCTURE OF PHACUS SPLENDENS cidae have arisen and (2) they are the sources of the POCHMAN (EUGLENOPHYTA) plastids, through secondary endosymbioses, for the Cryptophyta, Haptophyta, and the Heterokonta. To Nudelman, M. A.1, Leonardi, P.2, Farmer, M. A.3 1 understand Bangiophycidae phylogeny and to gain & Conforti, V. further insights into red algal secondary endosymbio- 1 Lab. Biologia Comparada de Protistas, Dpto Cs. Bio- ses, we sequenced the plastid-encoded small subunit logicas, FCEyN, Universidad de Buenos Aires,1428, ribosomal DNA coding region (ssu rDNA) from nine Buenos Aires, Argentina; 2Lab. Plantas Avasculares, members of this subclass and from two members of Universidad Nacional del Sur, Bahia Blanca, Argen- the Florideophycidae. Phylogenetic analyses were per- tina; 3Center for Advanced Ultrastructural Research, formed with other red algal plus chlorophyll aϩc algal University of Georgia, Athens, USA plastid ssu rDNA coding regions. Our results are consistent with a monophyletic origin of the Florideophy- The general fine structure of P. splendens Pochman cidae forming a sister group of the Bangiales. The (Section Pleurapsis) is described. This Section com- Bangiophycidae is of a paraphyletic origin, and orders prises a series of species with very distinctive features such as the Porphyridiales polyphyletic and distrib- unshared by the majority of the members of the ge- uted over three independent red algal lineages. The nus. The cells are pear-shaped in frontal view, plastids of the heterokonts are most closely related to rounded at the anterior end, narrowed posteriorly ta- members of the Cyanidium - Galdieria group of Por- pering in a long twisted tail. In lateral view, the ante- phyridiales and are not directly related to cryptophyte rior margins are asymmetric, undulate to serrate. The and haptophyte plastids. The phylogenies provide pellicle is strongly striated, with ribs helically ar- strong evidence for the independent origins of these ranged, oriented to the left, concavely depressed be- “complex” algal plastids from different members of tween adajcent ribs. In transverse section, the pellicle the Bangiophycidae. outline shows a single microtubule in the middle of each rib, on the base of a central sulcus. The other two are located one at each side of the sulcus. Among 156 other distinguishing characteristics, the most remarkable feature is the presence of a single chloroplast, a SEPARATING POPULATION STRUCTURE fact never reported in this genus before since the min- FROM POPULATION HISTORY IN ASCO- imal observed number is two and most of the Phacus PHYLLUM NODOSUM (FUCALES) species have been described as having numerous, Olsen, J. L. & Stam, W. T. small and discoid chloroplasts. In longitudinal sec- Department of Marine Biology, Centre for Ecological & tion, a large, leaf-like parietal chloroplast is observed. Evolutionary Studies, University of Groningen, 9750 It extends along the entire cell, bearing three promi- AA Haren, The Netherlands nent cup-shaped paramylon caps on the external face. In transverse section is C-shaped. The unusual shape Ascophyllum nodosum is dominant seaweed along many and localization of the chloroplast and paramylon in rocky intertidal shores throughout the North Atlantic. this species resemble descriptions of Cryptoglena pigra, Next to the kelps, fucalean taxa such as Ascophyllum suggesting a closer relationship to this organism than are the largest macrophytes and provide important to other members of Phacus. habitat for invertebrates. Understanding the underlying genetic structure of natural populations over a 155 range of spatial scales can reveal how the causes of PHYLOGENY OF THE BANGIOPHYCIDAE structure may change with scales. Separating popula- (RHODOPHYTA) AND THE SECONDARY tion history from population structure may also be elucidated. The analysis is based on six polymorphic ENDOSYMBIOTIC ORIGIN OF ALGAL PLAS- microsatellite loci and Ͼ1000 individuals. Strong ge- TIDS netic structure at small spatial scale was found and is 1 2 Oliveira M. C. & Bhattacharya D. consistent with demographic models based on long- 1Dept. de Botânica, Inst. de Biociências, Univ. de São lived individuals, low recruitment and many sib mat- Paulo, R. Matão,Travessa 14, n. 321, 05508-900, ings. At large spatial scales only weak population dif- São Paulo, SP, Brazil; 2Department of Biological Sci- ferentiation was found. This is consistent with recent PSA ABSTRACTS 53 recolonization of the North Atlantic following the last material. Purified granules contained polyphosphate glacial maximum. as the major component, which seemed to protect proteins in the vacuole from breakdown. A predomi- 157 nant 70 kDa protein in purified granules accumulated PICOPHYTOPLANKTON SEASONAL CYCLE in the cell wall of wild-type cells and in granules of AT THE SIO PIER, LA JOLLA, CALIFORNIA wall-deficient cells, as revealed by immunolocaliza- tion. This protein entered vacuoles via small vesicles Palenik, B. P. from Golgi, which probably also introduced degrada- Scripps Institution of Oceanography, University of Cal- tive enzymes into this compartment. Vacuoles thus ap- ifornia, San Diego, La Jolla, CA 92093 USA parently serve as lysosome-like structures as well as secretory vesicles. The membranes of the chloroplast The abundance of phycoerythrin-containing cyano- envelope in cryo-fixed green cells were tightly ap- bacteria and picoeukaryotes in water samples from pressed except where the inner membrane invagi- the Scripps Institution of Oceanography pier have nated or the outer membrane protruded into the cy- been followed at least weekly for more than two years tosol. Whereas conventional fixation showed lack of using flow cytometry. These cyanobacteria show a sea- appression of thylakoid membranes in a chlorophyll sonal cycle with generally lower cell numbers during b-less mutant, these membranes appeared as large the winter, a “bloom” as water temperatures increase, grana in images of cryofixed cells. The enhanced im- and higher cell numbers during the summer. How- ages obtained with cryofixation allowed substantial re- ever the population abundance appears to be more finement of our knowledge of the ultrastructure of variable and the magnitude of the annual change in these algal cells. cell number is less than reported for coastal Massa- chusetts by Waterbury et al. (1986). Isolates have been obtained from pier samples and genetic characteriza- 159 tion using rpoC1 (RNA polymerase) sequence data is IDENTIFICATION OF A GLYCINE DECAR- in progress. The PUB:PEB chromophore ratios of iso- BOXYLASE GENE IN THALASSIOSIRA WEISS- lates assayed using fluorescence excitation spectra FLOGII: A PROBE FOR PHOTORESPIRA- range from about 0.4 (low PUB) to 0.7 (mid-PUB) for isolates grown under white light. The physiological TION IN DIATOMS and genetic characterization of isolates is being used Parker, M. S. & Armbrust, E. V. to examine the similarities and differences of cyano- Marine Molecular Biotechnology Laboratory, School of bacterial populations from different coastal regimes. Oceanography, Box 357940, University of Washing- Similarly a picoeukaryote has been isolated that has a ton, Seattle, WA 98195 flow cytometric signature similar to the natural population. It appears to be a small nonmotile prasino- Diatoms are responsible for a large percentage of CO2 phyte. fixation in the world’s oceans. The export of diatom- fixed carbon from the euphotic zone represents a ma- 158 jor sink of CO2 in the global C cycle. Under condi- 2 INTERACTION OF CHLOROPLAST AND tions of high light and high O /CO2, carbon fixation VACUOLES IN CHLAMYDOMONAS may be reduced due to photorespiration. The fixation of O2 in photorespiration produces low molecular Park, H., Roberson, R. W., Eggink, L. L., & weight metabolites that cannot be used in the Calvin Hoober, J. K. cycle and are either excreted from the cell or ineffi- Department of Plant Biology and Center for the Study ciently salvaged in the photorespiratory pathway. One of Early Events in Photosynthesis, Arizona State Uni- of the key enzymes of photorespiration is glycine de- versity, Tempe, AZ 85287 USA. carboxylase (GDC). We have cloned and sequenced a cDNA corresponding to the gene encoding the T-pro- Proteins synthesized within the chloroplast of Chlamy- tein of GDC from the centric diatom Thalassiosira domonas reinhardtii were recovered in granules within weissflogii. This cDNA is 1100 bp and its predicted vacuoles (Park et al., J. Phycol. 35,528-538, 1999). Apo- amino acid sequence shows a 45% identity and a 62% proteins of light-harvesting complexes, synthesized in homology with the T-protein from higher plants. The the cytosol in excess of the capacity of the chloroplast first 20 amino acids display characteristics of mito- to synthesize chlorophyll, also were recovered in vacu- chondrial transit peptides, consistent with the local- olar granules. The ultrastructure of conventionally- ization of GDC in the mitochondria of higher plants. and cryo-fixed cells revealed protuberances of the Using competitive RT-PCR we have demonstrated chloroplast envelope outer membrane that contained that transcription of this gene is light-dependent. stroma-like material and also connections between Cells maintained at constant growth-saturating light the outer membrane and vacuolar membrane. Trans- conditions have much higher levels of T-protein mes- fer of proteins via these structures to vacuoles ap- sage than cells kept in the dark for 25 hours. We are peared to be a pathway for degradation of chloroplast currently investigating the effect of other environ- 54 PSA ABSTRACTS mental parameters, such as O2 concentration, on T- cies in both seasons but uptake rates were 2–5 times protein gene transcription. Ultimately, the goal is to greater in summer compared to winter. Ammonium use this gene as a probe for diatom photorespiration uptake was highest in all species regardless of season, in the field. To this end, we are developing degener- indicating a preference for this form of nitrogen. For ate primers and sequencing this gene from other dia- all species, urea uptake was negligible during winter tom species. but represented a substantial proportion of the total nitrogen taken up during summer. Comparison of 160 species in relation to their shore position revealed differences in uptake rates for each nitrogen source. TAXONOMIC REASSESSMENT OF THE These results suggest that intertidal seaweeds growing GENUS PADINA (DICTYOTALES, PHAEO- at different shore positions employ different strategies PHYTA) IN THE GULF OF CALIFORNIA, for procuring nitrogen in an environment where nu- MÉXICO trient supply may be limited. Paul-Chávez, L., Riosmena-Rodriguez, R., & Angeles-Pérez, A. 162 Herbario Ficológico, Mar. Biol. Dept., UABCS, Ap. SONDERELLA, LEMBERGIA AND THE NEW Postal 19-B, La Paz B.C.S. 23080 México TRIBE SONDERELLEAE (RHODOMELACEAE, RHODOPHYTA) Padina is one of the most important genera in the Phillips, L. E.1, Nelson, W. A.2 & Kraft, G. T.1 coastal zone of the Gulf of California because of their 1 biomass. Eight species have been recorded for the School of Botany, University of Melbourne, Victoria 2 area: P. tetrastromatica, P. durvillaei, P. gymnospora, P. 3052, Australia; Museum of New Zealand Te Papa mexicana, P. caulencens, P. concrescens, P. crispata y P. vi- Tongarewa, PO Box 467, Wellington, New Zealand keersiae based on taxonomic and floristic studies. Un- fortunately, until today, a comparative study of all The monospecific genus Sonderella is endemic to Aus- these species in a modern context was not available. tralia and has been the subject of speculation with re- Intensive surveys in 100 localities around the area gard to its taxonomic position. When the anatomy yield more than 1000 specimes and 500 slides were and reproduction of this genus were comprehensively analyzed and compared with relevant types. Taxo- described by Womersley in 1965, he recommended its nomic evaluations were developed using 16 characters inclusion in the Rhodomelaceae and foreshadowed commonly used in the literature. As a result of our that it would warrant its own tribe. Recent molecular analysis, only five characters can discriminate species. investigation has confirmed its position within the Based on character analysis and comparisons with Rhodomelaceae. Classical anatomical investigation of proper type material, only three species can be recog- the rare and poorly-known New Zealand endemic ge- nized in the zone: P. concrencens, P. durvillaei and P. nus Lembergia has shown that it shares many features mexicana. In the case of P. crispata, we conclude that it with Sonderella, including vegetative construction and is a heterotypic synonym for P. mexicna. But in the position and construction of the reproductive struc- case of P. gymnospora, P. tetrastromatica and P. vikersiae, tures. Molecular investigations of the 18S rRNA gene all previous records represent mis-identifications. support the close relationship of the two genera and their inclusion within the Rhodomelaceae as a separate tribe, the Sonderelleae tribus novum. 161 SEASONAL AND ZONAL VARIATION IN NITROGEN SOURCE FOR FOUR INTER- 163 TIDAL SEAWEEDS FROM NEW ZEALAND TAXONOMY OF THE LENORMANDIA - LENOR- Phillips, J. C. & Hurd, C. L. MANDIOPSIS COMPLEX (RHODOMELACEAE, Department of Botany, University of Otago, P. O. Box RHODOPHYTA) 56, Dunedin, New Zealand Phillips, L. E.1, Nelson, W. A.2 & Kraft, G. T.1 1School of Botany, University of Melbourne, Victoria Seasonal patterns in nitrogen uptake by four species 3052, Australia; 2Museum of New Zealand Te Papa of intertidal macroalgae (Stictosiphonia arbuscula, Apo- Tongarewa, P. O Box 467, Wellington, New Zealand phlaea lyallii, Scytothamnus australis, Xiphophora gladi- ata) from Otago in New Zealand’s south island were The genus Lenormandia is composed of nine species investigated. Field-collected material from species oc- from Australia and New Zealand. Some of the these curring at different shore heights was exposed to inor- are well known, but others are rare, obscure and ill- ganic (NOϪ3, NHϩ4) and organic (urea) nitrogen at defined. We have examined material of all described different concentrations (5␮M, 30␮M), and the rate species and found that they fall into two discrete of uptake over 30min intervals for 3hr was deter- groups that differ in apex morphology and position of mined. Active uptake of nitrate was shown by all spe- reproductive structures. Plants of the first group, con- PSA ABSTRACTS 55 taining the type species L. spectabilis, have a cleft apex on a global scale. For example, species east of the Isth- and reproductive structures produced directly on the mus of Panama form a distinct well-resolved clade blade surface, whereas those of the second group within the tropical subgenus. This result in sharp con- have a strongly inrolled apex and produce reproduc- trast to traditional systematic treatments but provides tive structures dorsally on small branchlets which arise a window into the evolutionary history of this genus in either from the margins or the midrib. The groups the Pacific and Atlantic Ocean basins and a possible were also found to form discrete clades on analysis of means to time speciation events. 18S rRNA sequences. All the members of the first group are endemic to Australia, whereas the second 165 group, designated by the new genus name Adamsiella, contains two previously described New Zealand spe- MODULATION OF VERY-LONG CHAIN (C28) cies and a single Australian representative. In addi- HIGHLY UNSATURATED FATTY ACIDS IN tion, two new species are described in this group from PROROCENTRUM MININUM (DINOPHYCEAE) New Zealand. Members of the closely related genus BY SELENIUM Lenormandiopsis were also examined and the type spe- Place, A., Adolf, J. E. & Lund, E. cies, L. latifolia, was found to conform in apex mor- Center of Marine Biotechnology, Columbus Center, phology and position of reproductive structures to the East Pratt Street Center, Baltimore, MD 21202 USA genus Lenormandia. Accordingly Lenormandiopsis has been subsumed within Lenormandia. The remaining Recently, very-long-chain (C28) highly unsaturated three members of the former genus Lenormandiopsis, fatty acids (VLC-HUFA) were identified in seven ma- however, were found to differ from both the type spe- rine dinoflagellate species (Manour et al., Phytochem- cies and the genus Lenormandia and consequently istry, 1999, 50: 541–548). In general, the proportion have been transferred to the separate genus Geraldia, of these fatty acids accounted for less than 2.3% of the along with a new species from Geraldton, Western total fatty acids in these species. As part of a study in- Australia which is designated as the type. vestigating the modulation of the hemolytic fatty acid 18:5n3, cultures of Prorocentrum mininum were grown 164 in artificial seawater with varying molarities of sodium GLOBAL SYSTEMATIC AND PHYLOGE- selenite (0, 1, 10, and 100 nM). Optimal growth was observed at 1 nM with this media. As expected, the NETIC ANALYSIS OF SARGASSUM IN THE level of 18:5n3 was modulated by the selenium in the GULF OF MEXICO, CARIBBEAN AND culture medium (7.0 Ϯ 0.2, 14.5 Ϯ 0.6, 7.4 Ϯ 0.8, and PACIFIC BASIN 3.9 Ϯ 0.8% of total fatty acid, respectively), with the Phillips, N.1, Smith, C.2, Morden, C.2, & highest percentage found at 1 nM. Unexpectedly the Fredericq, S.1 level of VLC-HUFA (28:8n3) increased to 7.3 Ϯ 2.8% 1Department of Biology, University of Louisiana at at 0 nM sodium selenite, while at all other selenite Lafayette, Lafayette, La. 70504 USA; 2Botany Depart- concentrations the VLC-HUFA was less than 1%. A ment, University of Hawaii, 3190 Maile Way, Hono- possible biochemical basis for this finding will be dis- lulu, HI 96822. USA cussed.

Sargassum is one of the most species-rich genera in the 166 brown algae with over 400 described species world- CALCIUM OXALATE CRYSTALS IN THE wide. The bulk of these species occurs in Pacific-In- GREEN ALGA SPIROGYRA SP. (ZYGNE- dian ocean waters with only a small portion found on MATALES, CHLOROPHYTA) the Atlantic side of the Isthmus of Panama. Sargassum also has one of the most subdivided and complex tax- Pueschel, C. M. onomic systems used within the algae. Systematic dis- Department of Biological Sciences, State University of tinctions within the genus are further complicated by New York at Binghamton, Binghamton, NY 13902 high rates of phenotypic variability in several key mor- USA phological characters. Molecular analyses in such systems should allow testing of systematic concepts while Specimens of an unidentified species of the freshwa- providing insights into speciation and evolutionary ter green alga Spirogyra were found to have abundant patterns. Global molecular phylogenetic analyses us- cruciate cellular inclusions up to 34 micrometers ing both conserved and variable regions of the long. A crystalline nature was shown by birefringence Rubisco operon (rbcL and rbcL-IGS-rbcS) were per- in polarized light. Despite their large size and com- formed with species from the Gulf of Mexico, Carib- plex shape, these inclusions did not occur free in the bean, and Pacific basin. Results confirm earlier analy- large central vacuole. Instead, they were associated ses based on rbcL-IGS-rbcS from Pacific species at the with cytoplasmic strands that spanned the space be- subgeneric and sectional level while providing addi- tween gyres of the parietal spiral chloroplasts and with tional insights into the systematics and phylogenetics strands that suspended the nucleus in a cytoplasmic 56 PSA ABSTRACTS embayment of the central vacuole. Some crystals 168 moved directionally along the cytoplasmic strands, PATTERNS AND CONSEQUENCES OF SPORE and their movement was arrested by cytochalasin B, DISPERSAL IN THE GIANT KELP, MACROCYS- suggesting that actin microfilaments had a role in TIS PYRIFERA crystal movement. Solubility tests showed that the in- 1 2 3 clusions were composed of calcium oxalate; they dis- Reed, D. C. , Raimondi, P. T. , & Washburn, L. 1 solved rapidly in weak hydrochloric acid without effer- Marine Science Institute, University of California, vescence, but they were not soluble in concentrated Santa Barbara, CA, 93106, USA; 2Department of Biol- acetic acid or sodium hypochlorite. A colorimetric en- ogy, University of California, Santa Cruz, CA, 95064, zymatic test for oxalate was used to demonstrate mi- USA; 3Department of Geography, University of Califor- croscopically the presence of oxalate and to quantify nia, Santa Barbara, CA 93106, USA the amounts. The calcium oxalate crystals were sur- rounded by a water-soluble organic matrix that re- We investigated patterns of spore dispersal in the gi- tained the shape of the crystal even after demineral- ant kelp Macrocystis pyrifera by collecting 80 indepen- ization. Scanning electron microscopy was used to dent measurements of spore dispersal from isolated examine the morphology of isolated crystals. individuals and isolated groups of individuals over a two-year period. Our results indicate that giant kelp spores routinely disperse both short (i.e. a couple meters) and long (i.e. hundreds to thousands of 167 meters) distances depending on the oceanographic EXCHANGES OF INFORMATION, ENERGY & conditions. One consequence of spore dispersal over MATERIALS IN SYMBIOSES short distances is self-fertilization (i.e., fertilization be- Raven, J. A. tween male and female gametophytes derived from the same sporophyte). Field experiments designed to Department of Biological Sciences, University of test the effects of self-fertilization on lifetime fitness in Dundee, Dundee DD1 4HN, United Kingdom Macrocystis revealed significant inbreeding depression. Birth rates in self-fertilized populations were ca. 50% Symbiosis is important in the cell and environmental of those produced from outcrossing, which lead to biology of algae. Some examples involving the author significant differences in cohort size that persisted up and numerous collaborators include: 1) chloroplasts through the adult stage. In contrast to outcrossed of eukaryotic algae arose from endosymbioses. Plas- populations, very few individuals produced from self- tids are incapable of independent existence; most of ing became reproductively mature, and those that did the genes of the cyanobacterial photobiont have been were significantly less fecund than outcrossed individ- lost, and the majority of the rest have been trans- uals. By contrast, long-range dispersal of spores leads ferred to the nuclear genome. Some of the genes re- to increased rates of outcrossing. However, long-range tained by the plastid are those whose transcription is dispersal is typically accompanied by massive dilution controlled by environmental cues transduced by the of spores, leading to low densities of spore settlement. organelle. The general trend is for organelle genes to Sparse spore settlement decreases the overall chance be transferred to the nucleus, escaping plastid redox of fertilization in the microscopic gametophyte gener- activities generating mutagenic free radicals; 2) symbi- ation thereby reducing the potential for colonization oses involving potentially free-living photobionts in- of the macroscopic sporophyte stage. Large popula- clude marine lichens and sponges with cyanobacterial tion size of adult sporophytes coupled with the syn- symbionts. For the lichen, Lichina, inorganic carbon chronous release of spores in response to environ- acquisition appears to involve inorganic carbon trans- mental cues can help offset the effects of spore port by the mycobiont, and for the sponge, Cymbas- dilution and extend the distances over which giant tella, the flagellar activity of the sponge is probably kelp is able to colonize. important for inorganic carbon supply to the photobiont; 3) the Australasian fucalean, Notheia, is an obli- gate epiphyte on the fucaleans, Hormosira and Xipho- 169 phora; the four species involved all contain the THE COMPOSITION AND TOXICITY OF hexitol, altritol. Notheia anomala is known to be phylet- DINOFLAGELLATE BLOOMS IN THE SAL- ically-distant from the other five altritol-containing TON SEA, CALIFORNIA species. Can Notheia synthesize altritol, or is it ob- Reifel, K. M.1, Tiffany1, M. A.1, McCoy, M. P.2 & tained from the phorophyte?; 4) Sacoglossan gastro- Hurlbert, S. H.1 pods retain kleptoplastids (not strictly symbionts) 1 from ulvophycean (or rhodophycean) marine algae. Department of Biology and Center for Inland Waters, Analyses of the natural abundance of stable carbon San Diego State University, 5500 Campanile Drive, isotopes suggest significant contribution of klepto- San Diego, CA 92182 USA; 2Scripps Institution of plastid photosynthesis to the carbon and energy bud- Oceanography, University of California at San Diego, get of the mollusks. La Jolla, CA 92093-0212 USA PSA ABSTRACTS 57

Phytoplankton blooms have been implicated in mor- lack of P limitation. This observation was supported tality events of diverse groups of organisms including by low bulk AP activity in the initial field samples. Dur- fish, birds and humans. About 300 species have been ing the experiment, several chlorophyte taxa (Coelas- reported to form “red tides,” or surface discolorations trum, Eudorina, a solitary spiny coccoid) were driven to due to high densities, but only 60–80 of these species P limitation, as evidenced by a high percentage of produce harmful blooms. In marine systems, di- cells displaying ELF labeling when inorganic N was noflagellates account for 75% of all harmful algal added. Taxa such as Actinastrum and Dictyosphaerium, bloom species. The Salton Sea is a large saline lake lo- on the contrary, were never P limited. Little or no cated in southeastern California, USA. The lake is ELF was observed in cyanobacterial species, suggest- eutrophic largely because it is in a closed basin and re- ing that P limitation was not achieved in these organ- ceives most of its input from agricultural and munici- isms. Using traditional bulk AP activity, significantly pal wastewaters. Dinoflagellates comprise a significant higher levels of AP activity were observed in treat- portion of the phytoplankton biomass, particularly in ments with inorganic N additions, compared to those winter, often resulting in “red” or “brown” tides. To with phosphate additions. ELF labeling generally fol- date, 16 species of dinoflagellates have been identi- lowed the trend of bulk AP, except in species that did fied from the Salton Sea, and many other unidenti- not dominate the biomass. Finally, we noted that all fied forms have also been documented. In 1992, species observed were ELF labeled at least on one oc- 150,000 eared grebes were found dead over a period casion, except for fragile flagellates which did not of several months at the Salton Sea. This mortality withstand the labeling procedure. event was among the largest of any bird species. The principal cause remains unknown, but algal toxins 171 were suspected. A survey of the composition and tox- RANGE EXTENSION OF CUTLERIA HAN- icity of algal blooms was undertaken in 1999, and we COCKII (CUTLERIALES; PHAEOPHYTA) TO report results from blooms where dinoflagellates THE SOUTHWESTERN GULF OF CALIFOR- dominated. Dominant species included Gonyaulax grindleyi, Gymnodinium spp., Gyrodinium uncatenum, NIA, MÉXICO Heterocapsa niei, and an unidentified scrippsielloid. Al- Riosmena-Rodríguez, R., Paul-Chávez, L. & Hino- though most samples showed activity in a brine josa-Arango, G. shrimp lethality assay, all were negative in a mouse Hebario Ficológico, Depto. Biol. Mar., U.A.B.C.S., Ap. bioassay. This evidence suggests that toxins from di- postal 19-B, La Paz B.C.S. 23080, México noflagellate blooms in the Salton Sea are not responsible for eared grebe mortality events. A range extension of Cutleria hancockii Dawson to the southern portion of the Gulf of California is pre- 170 sented based on collections in Concepción Bay, La Paz Bay and Muertos Bay between March, 1996 and SPECIES-SPECIFIC RESPONSE IN ALKALINE May, 2000. Mature gametangial and sporangial plants PHOSPHATASE ACTIVITY OF FRESHWATER were collected in several localities in the low intertid- PHYTOPLANKTON IN A NUTRIENT ENRICH- ial zone and in subtidial areas. The present records MENT EXPERIMENT represent a range extension of 500 km for the species Rengefors, K.1, Haupert, C.2, Ruttenberg, K. C.2, with the new southern limit in Punta Perico in Los Taylor, C.1, Howes, B. L.3, & Anderson, D. M.1 Muertos Bay. The plants mostly were observed in low 1Biology Department, Woods Hole Oceanographic Insti- intertidial-shallow subtidial areas associated with Sar- tution, Woods Hole, MA 02543 USA; Department of gassum forest, but also were observed at depths of 30 Chemistry and Geochemistry, Woods Hole Oceano- ft. Based on analysis of the basic morphological and anatomial features of the plants, significant differ- graphic Institution, Woods Hole, MA 02543 USA; 3 ences within geographic position and depth distribu- University of Massachusetts Dartmouth, Dartmouth, tion were noted. Our data suggest that the tempera- 285 Old Westport Rd., North Dartmouth, MA 02747 ture may be the determining factor in the USA distribution of this species.

A new method was utilized to study species-specific re- 172 sponses of phytoplankton to phosphorus limitation in DEMOGRAPHY OF FRONDS OF SARGASSUM a nutrient enrichment experiment. A substrate, ELF, LAPAZEANUM FROM SOUTHERN BAJA CALI- produces a fluorescent precipitate at the sites of alka- FORNIA, MEXICO, DURING EARLY STAGES line phosphatase (AP), which makes it possible to vi- 1 2 sually detect phosphorus (P) limitation in individual Rivera, M. G. & Scrosati, R. 1 cells of multiple species. Lake water was incubated in Centro Interdisciplinario de Ciencias Marinas, AP the laboratory to induce nitrogen (N) or P limitation. 592, La Paz, 23000 BCS, Mexico; 2Centro de Investi- Initially, little or no ELF labeling was observed for any gaciones Biologicas del Noroeste, AP 128, La Paz, of the phytoplankton species, indicating a general 23000 BCS, Mexico 58 PSA ABSTRACTS

In terms of biomass, Sargassum lapazeanum (Phaeo- circadian rhythm of bioluminescence and of lu- phyceae, Fucales) is one of the most important sea- ciferase abundance, the presence/absence of the lu- weeds in La Paz Bay, on the southeastern coast of the ciferin-binding protein, and the molecular structure Baja California Peninsula, Mexico. This species can be of the luciferase gene. We anticipate that this ap- found year-round in shallow subtidal sites. Standing proach will distinguish between regions of the lu- biomass is lowest between fall and winter and highest ciferase molecule that are conserved for enzyme func- between spring and summer. We are currently study- tion versus those concerned with the regulation of ing the annual demography of fronds as a necessary protein expression. In addition, it will provide insight step to understanding the mechanisms of population into the evolution of the regulatory processes and regulation. Work is being done on a bed of about 90 pathways. m in length and three m in width. At this stage of ab- stract submission, we can report results for winter only. 174 Random samples were collected in February and in ANALYSIS OF NUCLEAR MUTANTS OF March 2000 to estimate stand biomass, frond density, CHLAMYDOMONAS DEFICIENT IN THE ACCU- and size (frond length) structure. In addition, we la- MULATION OF SPECIFIC CHLOROPLAST beled fronds with numbered plastic tags to estimate their rates of growth and of mortality during this period. RNAS 1 1 2 Rates of recruitment were estimated from a combined Rochaix, J. D. , Boudreau, E. , Nickelsen, J. , analysis of the above. In February, fronds were all Lemaire, S.1, Vaistij, F.1 & Goldschmidt-Clermont, shorter than 6.5 cm. Between February and March, mean M.1 total frond density increased from 122 to 776 fronds 1Departments of Molecular Biology and Plant Biology, mϪ2 (n ϭ 30 quadrats). The mean recruitment rate University of Geneva, Geneva, Switzerland; 2Ruhr was 667 fronds mϪ2, the mean growth rate was 0.5 cm Universität, Bochum, Germany dayϪ1 (n ϭ 60 fronds), and the mean mortality rate Ϫ2 was 43 fronds m . From last year’s preliminary obser- Genetic analysis has revealed that the accumulation of vations, we expect to observe peaks of biomass and of several chloroplast mRNAs of the green alga Chlamy- reproduction in late spring, followed by negative domonas reinhardtii requires specific nucleus-encoded growth rates and high mortality rates during summer. functions. We have characteized three nuclear mutants, nac2, 222E and F24 which lack psbD, psbB and 173 psaB mRNA, respectively. In each case we have shown EVOLUTION OF BIOLUMINESCENCE IN that the target of the nucleus-encoded function af- MARINE DINOFLAGELLATES fected in these mutants is the 5Ј untranslated region Robertson, D. L. & Hastings, J. W. of the corresponding mRNA (3, 4, 5). We have cloned Department of Molecular and Cellular Biology, Har- the nuclear Nac2 and Mbb1 genes by rescue of the mutants which are deficient in the accumulation of vard University, Cambridge, MA 02139 USA the mRNAs of psbD and the psbB/psbT/psbH chloroplast transcription unit.. Nac2 encodes a hydrophilic Bioluminescence is broadly distributed in marine di- polypeptide of 1385 amino acids with 9 tetratricopep- noflagellates and has been intensively studied in Lin- tide repeats (TPR) in its C-terminal half whereas gulodinium (Gonyaulax) polyedra. In this species, biolu- Mbb1 encodes a polypeptide of 662 amino acids minescence is regulated in a circadian fashion; the which also contains 9 TPRs. Both proteins contain a enzyme (luciferase) and the luciferin (substrate)- putative chloroplast transit peptide at their N-termi- binding protein are synthesized and degraded on a nal end. They have been tagged with the HA epitope daily basis. Synthesis of both proteins is regulated at and localized in the stromal compartment of the chlo- the level of translation. The L. polyedra luciferase gene roplast. Nac2 and Mbb1 are part of a high molecular is composed of three contiguous domains that are weight complex of 500 and 250 kDa, respectively, greater than 75% identical at the nucleic acid level. which is associated with RNA in the case of Nac2. A Possible explanations for the high degree of se- change of a conserved Ala residue of the fourth TPR quence conservation include: (1) the domains evolved motif by site-directed mutagenesis completely abro- through a recent duplication event; (2) the sequence gates Nac2 function indicating that this TPR is impor- similarity is maintained by a molecular process such as tant for psbD mRNA stability, processing and/or gene conversion; or (3) there is a functional role asso- translation. ciated with the primary nucleic acid sequence, such as in the translational regulation of luciferase expres- 175 sion. The phylogenetic relationship of dinoflagellates predicted from 18S rDNA genes provides a frame- PRELIMINARY FLUORESCENCE AND ULTRA- work for examining the molecular evolution of the STRUCTURAL OBSERVATIONS IN DICTY- regulation of luciferase expression and of genes en- OSPHAERIUM PULCHELLUM (CHLOROCOC- coding luciferase and the luciferin-binding protein. CALES, CHLOROPHYCEAE) In particular, we are examining the evolution of the Rodríguez, M. C.1, de la Peña, G. & Leonardi, P. I.2 PSA ABSTRACTS 59

1Departamento de Ciencias Biológicas, Facultad de teins to decrease and heat shock proteins (HSPs) to Ciencias Exactas y Naturales, Universidad de Buenos increase. HSPs are categorized by molecular weight Aires, 1428 Buenos Aires, Argentina; 2Departamento among five classes with each apparently specialized de Biología, Bioquímica y Farmacia, Universidad Na- for a particular function that enhances cell survival. cional del Sur, 8000 Bahía Blanca, Argentina One-dimensional SDS-PAGE of diatoms subjected to heat treatment revealed that P. tricornutum exhibited a typical stress response, but C. muelleri did not exhibit a Dictyosphaerium pulchellum is a common freshwater characteristic response even at a greatly elevated tem- phytoplankter. After cell division, autospores remain perature (50Њ C). This result was confirmed by total attached to each other in a characteristic fashion soluble protein assays. Chaetoceros muelleri may contain through the remnants of the partially hydrolyzed higher basal levels of HSPs than P. tricornutum allow- mother cell walls (tracts), originating up to 64-celled ing C. muelleri to better tolerate elevated tempera- colonies immersed in abundant mucilage. Staining tures. Western blot analysis using pea HSP70 (70 kDa) with ruthenium red and toluidine blue revealed muci- antisera of heat-treated P. tricornutum and C. muelleri lage acid properties, probably due to uronic acids in validated the hypothesis that thermo-tolerant cells polysaccharides. Tracts and cell walls were Periodic contain higher levels of constitutively expressed HSPs. Acid-Schiff positive and showed fluorescence with cal- Two-dimensional gel electrophoresis of heat-treated cofluor white, indicating the presence of fibrillar cells indicate that the small HSPs (17–30 kDa) played polysaccharides of the type cellulose and beta-man- a role in the stress response similar to that found in nans. Intense fluorescence with berberine suggested vascular plants. Ongoing work is focused on the ma- some hydrophobic coating of fibrillar polysaccha- nipulation of the stress response through over-expres- rides. Though cell walls proved to be acetolysis resis- sion of key hsp genes. tant, no secondary fluorescence was observed with primuline, suggesting that the hydrophobic polymer in the cell wall differed from algaenan. Ultrastructural observations revealed no trilaminar structure in the 177 cell wall, but ruthenium red stained sections exhib- REVISED CLASSIFICATION OF THE GENUS ited a “zipper-like” band in the outermost cell wall PACHYMENIA BASED ON MORPHOLOGICAL layer both in autospores and mother walls. The cells AND MOLECULAR CHARACTERS have a large cup-shaped chloroplast containing a sin- Russell, L. K.1, Hurd, C. L.1, Nelson, W.A.2, gle pyrenoid with the matrix traversed by double thy- 3 4 lakoids and circled by starch plates. A lobulated nu- Falshaw, R. , & Broom, J. E. 1 cleus occupied the concavity of the chloroplast. Botany Department, Otago University, P.O. Box 56, Dictyosomes appeared closely related with the nuclear Dunedin, New Zealand; 2Museum of New Zealand Te envelope. Several vacuoles scattered in the cytoplasm Papa Tongarewa, P.O. Box 467, Wellington, New and close to the nucleus showed electron dense con- Zealand; 3Industrial Research Limited, P.O. Box 31- tent, which could also be observed in the periplas- 310, Lower Hutt, NZ; 4Biochemistry Department, malemmal space. Fluorescent dye quinacrine also Otago University, P.O. Box 56, Dunedin, New showed active vesicle traffic. Zealand

Taxonomic discrimination in the genus Pachymenia 176 (Rhodophyta) in New Zealand is based primarily on PROTEIN EXPRESSION DURING HEAT phenotypic characters of the thallus. The taxonomic STRESS IN THERMO-INTOLERANT AND problems raised by this classification method are due THERMO-TOLERANT DIATOMS to highly variable thallus characters such as blade thickness, blade width, degree of thallus branching, Rousch, J. M., Bingham, S. E., & Sommerfeld, M. and variation in anatomical characters. Delineation of R. species is further complicated by a lack of adequate Department of Plant Biology, Arizona State University, knowledge about the responses of phenotype to envi- Box 871601,Tempe, AZ 85287 USA ronmental variation. There are currently three species recognized in this genus that are endemic to New To better understand how diatoms are capable of re- Zealand: a prostrate species P. crassa, and two erect sponding to environmental stress, protein expression species, P. laciniata and P. lusoria. In this study, two ap- during heat treatment of a thermo-intolerant (Phaeo- proaches are used to investigate the current delinea- dactylum tricornutum) and thermo-tolerant (Chaetoceros tion of these species. Morphological and anatomical muelleri) diatom (Chrysophyta) was investigated. The characters of field collected material and herbarium stress response is a universal and conserved mecha- specimens from throughout the species’ distribu- nism of cell survival to unfavorable conditions. Typi- tional ranges were quantified. Multivariate analyses cally, a 10 to 15Њ C temperature elevation above cell were used to identify discrete phenotypic groups. Spe- growth optimal causes constitutively expressed pro- cies relationships were further analyzed by quantify- 60 PSA ABSTRACTS ing the variation found within the internal tran- 179 scribed spacer region (ITS) of the nuclear ribosomal PREDAEA LUCESCENS SP. NOV., A NEW DNA. The results obtained from both approaches will COOL-TEMPERATE AUSTRALIAN SPECIES be discussed with regards to possible re-classification WITH UNIQUE, UNDIFFERENTIATED NUTRI- of species relationships within this genus. We suggest that the two erect species should be merged, and the TIVE FILAMENTS 1 2 currently recognized P. lusoria should be separated Saunders, G. W. & Kraft, G. T. into at least two taxonomic groups. 1Department of Biology, University of New Brunswick, Fredericton, NB, Canada; 2School of Botany, Univer- sity of Melbourne, Parkville, Victoria 3052, Australia

The red algal genus Predaea (Schizymeniaceae, Gigar- 178 tinales) includes approximately a dozen species of COALESCENCE VERSUS COMPETITION: tropical and subtropical distribution. Plants are gelati- FIELD AND LABORATORY STUDIES OF INTRA- nous in consistency, and the carpogonial branches AND INTERSPECIFIC ENCOUNTERS AMONG and auxiliary cells are widely separated in female ga- COALESCING SEAWEEDS metophytes (non-procarpy). Predaea is distinguished Santelices, B., Correa, J. A., Aedo, D., from other red algal genera in possessing clusters of Hormazábal, M. & Flores, V. small rounded nutritive cells that are borne on the Departamento de Ecología, Facultad de Ciencias Bi- one proximal and distal two cells directly attached to the auxiliary cell. We describe a new species from cool- ológicas, P. Universidad Católica de Chile, Casilla temperate (10–18Њ C yearly range) southeastern Aus- 114-D, Santiago, Chile tralia that, unlike the tropical and subtropical species, lacks the typical gelatinous texture and has dwarf veg- Classical ecological theory predicts that whenever etative filaments of normally contoured cells associ- growing individuals share a common and limiting re- ated with the auxiliary cell rather than small clusters source, such as substratum in mid-intertidal and shal- of spherical nutritive cells. Anatomical and molecular low subtidal habitats, preemptive competition will oc- data are combined to postulate the phylogenetic af- cur determining species abundance and distribution finities of the new species to others of the genus, to patterns. However, conspecificity of several ecologi- highlight relationships of Predaea to other genera of cally dominant Rhodophyta may coalesce when grown the Schizymeniaceae, and to consider this family rela- in laboratory cultures. The extent at which intraspe- tive to others now placed in the Gigartinales. cific coalescence occurs in the field and whether the process may also happens during interspecific encounters remain to be determined. If intra- and inter- 180 specific coalescence effectively occurs, then coexist- A CANDID ASSESSMENT OF SYSTEMATICS ence through coalescence rises as an alternative to IN THE LAMINARIALES: MUDDLED MOR- competition among red-algal dominated intertidal and shallow subtidal communities. Populations of PHOLOGIES AND SKETCHY SEQUENCES Mazzaella laminarioides and Nothogenia fastigiata living Saunders, G. W., Lane, C. E. & Mayes, C. in mid-intertidal, semi-exposed rocky habitats in Cen- Department of Biology, University of New Brunswick, tral Chile are being used to test the above ideas. Intra- Fredericton, NB, Canada and interspecific encounters occur in the field throughout the year. Coalescence does occur among Algae of the Alariaceae, Laminariaceae and Lessoni- conspecific partners but it has not been detected in aceae are the largest, most complex, and, arguably, interspecific encounters. Rather, a thick interface of most fascinating of the seaweeds. It is, therefore, a compressed cells, necrotic tissues and cyanobacterial profound paradox that these species remain in taxo- nodules is formed between the two contacting part- nomic chaos despite the contemporary emphases on ners. In addition, observations of laboratory cultures systematics. Setchell and Gardner established the clas- indicate that spore germination, germling survival sification system in 1925, recognizing these families and differentiation of erect axes in bispecific cultures on the basis of clear morphological features. At that may be reduced when compared to single-species con- time, however, they acknowledged that some species trols. Interspecific differences in growth and differen- had features consistent with placement in two fami- tiation rates appear as the mechanisms explaining a lies, or that obscured logical placement in any of the lack of coalescence and negative effects during inter- families. Ironically, the problems noted by Setchell specific contacts. On the other hand, the existence of and Gardner have been ignored and the system has conspecific coalescence in the field suggests this pro- become entrenched in kelp literature. Initial molecu- cess should be considered as a real alternative to in- lar studies highlighted the shortcomings noted by Set- traspecific competition among coalescing Rhodo- chell and Gardner, and further indicated that little of phyta. the morphology-based system was natural. It was obvi- PSA ABSTRACTS 61 ous that the diagnostic morphological features, pres- Many species of large brown algae co-occur along si- ence or absence of sporophylls and ontogenetic split- milar shores and depths and seem to share similar eco- ting, were ‘noisy’ being gained and lost independently logical characteristics in terms of habitat-formation, many times in kelp evolution. Despite the insights of providing nursery and feeding habitats for reef fish, the initial molecular studies, they had limitations and vertical structure of habitats within the water column key relationships remained unresolved. The investiga- and biomass production. However, the dominant spe- tions used the Internal Transcribed Spacers (ITS) of cies have very different life histories. Laminarians the ribosomal cistron that have phylogenetic limita- have a heteromorphic alternation of generations, tions owing to their short length, which is exacer- while fucaleans have an animal-like life history with bated by the many variable regions that can’t be more direct development. Despite these differences, aligned confidently and must be removed prior to there seems to be no obvious relationship between phylogenetic analyses. Many molecular publications life history and ecological function. Laminarians and have appeared subsequent to the first ITS results, and fucaleans seem generally to have very different de- their contribution towards elucidating kelp phylogeny mographies, with quite disparate features such as will be assessed. Current investigations using the propagule size and number, early survival, growth Large Subunit ribosomal DNA (LSU) for kelp system- rates, and densities of plants required for a closed can- atics will also be discussed. opy. Furthermore, few laminarians occur in the intertidal zone. Here, I will compare some species in these groups for which we know something about life his- 181 tory and ecology in New Zealand and the USA. Al- INTRODUCED MACROALGAE IN THE AUS- though it is necessary to understand life histories of TRALIAN REGION: CURRENT STATE OF individual species to understand their demography KNOWLEDGE and ecological functions, this is not sufficient in itself Schaffelke, B. & Campbell, M. L. to predict such roles and functions. CSIRO Centre for Research on Introduced Marine Pests, GPO Box 1538, Hobart, Tasmania 7001, Aus- 183 tralia “SCATTERED CP-NUCLEOIDS” IN DIATOMS EXPLAINED: BACTERIA - INSIDE THE ENDO- Introductions of non-native macroalgae and the sub- PLASMIC RETICULUM - PIERCE THE PLAS- sequent displacement of native species are globally TIDS OF PINNULARIA becoming more frequent. The algal genera Undaria, Schmid, A. M. Sargassum, Caulerpa and Codium have been identified Inst. f. Pflanzenphysiologie, Universität Salzburg, Hell- as being particularly invasive. An overview on the brunnerstr. 34, A-5020-Salzburg, Austria present knowledge on macroalgal introductions in the Australian region is presented and options for Geitler’s (1937) observation on the regular perfora- management are discussed, mostly using examples tion of the chloroplasts of Pinnularia nobilis and the from studies on the introduced Japanese kelp, lack of a typical pyrenoid is supported using cy- Undaria pinnatifida. Undaria pinnatifida was first de- tochemistry, and fluorescence & electron microscopy. tected in Tasmania, Australia in the early 1980’s. Chloroplast cavities and channels harbour bacteria, Since then, its range has expanded despite eradica- their DNA elicit DAPI-fluorescence. Previous speculation efforts. Long distance jumps appear to be the ma- tions on the DNA-positive, achromatic dots in the jor mode of spread of U. pinnatifida in Tasmania. plastids of several Pinnularia species being “scattered Studies are underway to distinguish the relative im- chloroplast nucleoids,” and the consequent separa- portance of spore dispersal, drift of adult plants and tion of diatom plastids in “primitive” and “advanced” anthropogenic factors in spreading this invasive kelp. types, are thus refuted. Bacteria are rod-shaped and as Although information on the real impacts of U. pin- suggested by their TEM-profiles gram-negative pro- natifida and other introduced macroalgae is sparse, teobacteria. They occur inside the endoplasmic retic- the development of management and control strate- ulum throughout the cell, in interphase prevailingly gies is of vital importance to prevent further spread in the space between the periplastidial membrane and translocation of these “pest” species. (PPM) and the CER membrane. Clusters of bacteria inside ER-cisternae near the nucleus in preprophase, 182 and near the new plasmalemma after cleavage, indi- CONTRASTING LIFE HISTORIES AND cates a cell-cycle dependent translocation within the diatom. Cavities in the plastids seem to be created by a DEMOGRAPHIES OF LAMINARIAN AND combination of mechanical and chemical forces, in FUCOID ALGAE the sequence: alignment, attachment, deformation Schiel, D. R. and lysis, initially without an obvious disruption of the Zoology Department, University of Canterbury, Christ- PPM and the chloroplast-envelope. Our future goal is church, New Zealand to identify the bacteria and their metabolic function 62 PSA ABSTRACTS in the hereditary association with the plastids in Pin- sequence analysis (rbcL and 18S rRNA genes) and nularia. Their intracellular, but extraplasmatic, loca- transmission electron microscopy. In both gene trees, tion may reflect an ancestral constellation, and the ap- Nemalionopsis and Thorea form well supported clades parent worldwide distribution may substantiate this (87–100% bootstrap values) separate from other mem- view. bers of the Batrachospermales as well as taxa from the Acrochaetiales, Palmariales, and Nemaliales. In addi- 184 tion, analysis of the secondary structure of the 18S rRNA gene in Nemalionopsis and Thorea reveals an ad- THE EFFECT OF SEAWEED DIETS ON ditional helix, which is not present in any of the other GROWTH OF GREEN ABALONE, HALIOTIS taxa within the Rhodophyta. Pit plugs of the Tho- FULGENS, FROM BAJA CALIFORNIA, MEXICO reaceae also differ from those of other members of Serviere-Zaragoza, E.1, Mazariegos-Villareal, A.1 the Batrachospermales in not having an outer cap & Ponce-Díaz, G.1,2 layer that is not universally domed. Based on these 1Centro de Investigaciones Biológicas del Noroeste findings, it is proposed that Nemalionopsis and Thorea (CIBNOR). P.O. Box 128, La Paz, Baja California represent a distinct taxonomic group that should be Sur. 23000. México; 2CICIMAR, IPN, La Paz, Baja recognized as a new order, the Thoreales. California Sur México 186 Two abalone species: green Haliotis fulgens and yellow Halioti corrugata represent nearly 97% of the total pro- SYSTEMATIC EVALUATION OF THE GENUS duction in the Mexican abalone fishery. It has been HILDENBRANDIA (RHODOPHYTA): A SYN- assumed that abalone feed on the kelp algae Macrocys- THESIS OF TECHNIQUES tis pyrifera. Regional hatcheries use this species as a Sherwood, A. R. & Sheath, R. G. main source of natural food. M. pyrifera does not oc- Department of Botany and Dean’s Office, College of Bi- cur at the southern limit of the distribution of aba- ological Science, University of Guelph, Guelph, ON, lone species along the Baja California Peninsula. In N1G 2W1, Canada this study, growth rates of juveniles H. fulgens, 17.3 Ϯ 2.2 mm shell length and 0.4 Ϯ 0.2 g body weight, were The evolutionary relationships among members of evaluated. Juveniles were fed with common species in the red algal genus Hildenbrandia have not been well the benthic environments inhabited by abalone along understood for several reasons. For example, the ge- the western coast of Baja California during 191 days. nus contains both marine and freshwater representa- Three diets were based on algae: palm kelp, Eisenia ar- tives, all of which are non-calcified and crustose, and borea, giant kelp, M. pyrifera and Gelidium robustum, few have definitive morphological characters for clas- and one on seagrass, Phyllospadix torreyi. Shell length sification. Hildenbrandia is also assumed to be com- Ϫ1 and body growth rates varied between 21.5 ␮m day pletely asexual (reproduction by tetrasporangia in Ϫ1 and 2.2 mg day for E. arborea and between 45.9 ␮m marine forms and by gemmae in freshwater popula- Ϫ1 Ϫ1 day and 6.7 mg day for M. pyrifera. Higher specific tions), and characters of the female gametangial sys- growth rates (SGR) in length and weight were deter- tem and post-fertilization structures are not available Ϫ1 mined for M. pyrifera: 0.2% and 0.7% day . Signifi- for comparative studies. Currently there are 14 marine cant differences between values of juveniles fed M. py- and five freshwater species and infraspecific taxa rec- rifera with the rest of the diets were found. The ognized within the genus. We used phylogenetic anal- highest mortality (21%) was in juveniles fed the red yses (parsimony, distance and maximum likelihood) algae G. robustum. of DNA sequences of commonly employed genes (rbcL and 18S rRNA) to examine the evolutionary re- 185 lationships among representatives of many of these A PROPOSAL FOR A NEW RED ALGAL taxa. In addition, we employed morphometrics (prin- ORDER, THE THOREALES cipal co-ordinates and cluster analyses) of several measured characters of these same representatives, as Sheath, R. G., Müller, K. M. & Sherwood, A. R. well as all available type specimens, to determine the Department of Botany and Dean’s Office College of Bio- number of morphologically-delimited entities within logical Science, University of Guelph, Guelph, ON, the genus. Thus far our results indicate that some N1G 2W1, Canada characters traditionally used to distinguish species of Hildenbrandia, such as tetrasporangial division pat- The freshwater red algal genera Nemalionopsis and Tho- tern, may not be useful in some cases, and a revision rea are currently classified in the family Thoreaceae of of the taxonomy of the genus will be necessary. Al- the Batrachospermales. However, these two genera dif- though the marine and freshwater species of Hilden- fer from other members of the order in having multiax- brandia appear to be well separated in our molecular ial thalli. The phylogenetic relationships of the gen- analyses of European specimens, this trend was not era were investigated using a combination of DNA observed for North American specimens. High se- PSA ABSTRACTS 63 quence divergence values were calculated for both Moss Landing Marine Laboratories, 8272 Moss Land- the rbcL and 18S rRNA genes of Hildenbrandia, coming Rd., Moss Landing, CA 95039 USA pared to other red algal genera. Deepwater macroalgal assemblages (DWAAS) were 187 sampled from 30m to their lower depth limits at 4 lo- GEOGRAPHICAL CORRELATION OF MOR- cations in central California using enriched air Ni- PHOLOGICAL VARIATION IN SILVETIA COM- trox and the ROV Ventana. The lowest observed PRESSA (FUCACEAE, FUCALES, PHAEO- depth limits were 78 m for nongeniculate (encrust- ing) coralline algae, 58 m for non-calcified red algae PHYCEAE) (i.e. Maripelta rotata), 40 m for foliose brown algae 1 1,2 1 Silva, P. C. , Pedroche, F. F. , Chacana, M. E. , (i.e. Desmarestia tabacoides), and 37 m for kelps (i.e. Aguilar Rosas, L. E.3, & Aguilar Rosas, R.4 Pleurophycus gardneri). Green algae, such as Derbesia 1University Herbarium, University of California, Ber- marina and an undescribed deep water species of Co- keley, CA 94720-2465 USA; 2Depto. de Hidrobiología, dium, were observed at 30m, while large patches of an Universidad Autónoma Metropolitana-Iztapalapa, Apdo. unknown green or blue-green algal film of coccoid Postal 55-535, México, D.F. 09340, México; 3Instituto cells were found from 45 to 48 m. DWAAS zonation de Investigaciones Oceanológicas, Universidad Au- was generally similar to that in southern California, tónoma de Baja California, Apdo. Postal 453, with subtle differences in the zonation of foliose red Ensenada, Baja California, México; 4Facultad de algae and the occurrence of an unknown Chloro- Ciencias Marinas, Universidad Autónoma de Baja phyta or Cyanophyta from 45–49m. Twenty four species of algae (13 Rhodophyta, 11 Phaeophyta) were California, Apdo. Postal 453, Ensenada, Baja Califor- sampled during the percent cover analysis at 30 m. nia, México Nongeniculate corallines varied from 53% to 91% cover depending on location, while geniculate coral- Silvetia compressa (J. Agardh) Serrão et al. is a common lines (i.e. Bossiella schmittii) averaged ca. 25% cover. member of the upper intertidal fucoid community on Pleurophycus gardneri, a stipitate kelp previously de- the Pacific coast of America from Humboldt County, scribed as “rare” in central California, was the most California, to Punta Baja, Baja California, Mexico. A abundant brown alga, averaging from 2.68 to 4.8 indi- relatively narrow range of morphological variability is viduals mϪ2. Algal abundance (percent cover and den- exhibited by most mainland populations, regardless sity), zonation, and light levels at the lower algal of latitude, but some mainland populations and all in- depth limits were similar between sites and locations, sular populations participate in a complex pattern suggesting that the environment of deep water algal that we have attempted to analyze. A few populations populations in this region is less variable than that of on the Monterey Peninsula in which the fronds are the shallow water kelp forest communities above atypically delicate were described by Setchell & Gard- them. ner as f. gracilis, to which was assigned a population from Santa Catalina Island. After comparing popula- 189 tions from various parts of the range of the species, including all of the Channel Islands, we conclude that POPULATION PARAMETERS AND PHOTO- two subspecies may be recognized. In subsp. compressa, SYNTHETIC CAPABILITIES OF CORALLINE which includes f. gracilis as a growth form and occurs RHODOLITHS: BIOGEOGRAPHIC IMPLICA- chiefly on the mainland, the frond is robust with long TIONS tapered receptacles. In the variant subspecies, which Steller, D. L.1, Cabello-Pasini, A.2 & Riosmena- is chiefly insular but also occurs on the coast of north- Rodriguez, R.3 ern Baja California, the typical frond has slender axes 1Biology Department, University of California-Santa as in f. gracilis, but is more densely branched and has Cruz, Santa Cruz, CA 95064 USA; 2Instituto de Inves- short ellipsoidal receptacles. Comparison of nucle- tigaciones Oceanológicas, Universidad Autónoma de otide sequences from the ITS regions of rDNA re- Baja California, A.P. 453, Ensenada, Baja California vealed an identical pattern for subsp. compressa from 3 Baja California and central California, including pop- 22800, Mexico; Dept. Biología Marina, Universidad ulations assignable to f. gracilis. By contrast, the pat- Autónoma de Baja California Sur, A.P. 19B, La Paz, tern for the variant subspecies differed by 2 bp (0.3%) Baja California Sur, Mexico from that of subsp. compressa. Rhodoliths are bed forming, unattached coralline al- 188 gae that incorporate large quantities of carbonate into their thalli in oceans worldwide. Lithophyllum mar- THE DISTRIBUTION AND ABUNDANCE OF garitae and Neogoniolithon tricotomun are common DEEPWATER MACROALGAE IN CENTRAL Rhodoliths from the Gulf of California, however, little CALIFORNIA is known about their biogeographic distribution, and Spalding, H. L. their ecological and physiological characteristics. As a 64 PSA ABSTRACTS consequence, the objective of this study was to define tion. These genes are akin to the products of gene du- the temporal population dynamics, growth rates and plication and provide a source of evolutionary novelty photosynthetic capabilities of L. margaritae and N. tric- that could significantly increase the genetic diversity otomun from the Gulf of California. The Gulf of of the host lineage. We postulate that this may be a California is characterized by annual temperature common phenomenon in algae containing secondary fluctuations that can exceed 20Њ C. Rhodolith beds ex- plastids that has yet to be fully appreciated due to a ceeding one km in length were observed from the dearth of evolutionary studies of nuclear genes in intertidal zone to a depth of approximately 20 m at these taxa. the southern Gulf. Percent cover estimates for spherical unattached individuals of L. margaritae and N. tric- 191 otomun ranged from 10 to 100%. Growth rates were THE EVOLUTION OF RNA POLYMERASE II determined by staining the rhodoliths with Alizarine red and evaluating the linear increment of calcium IN RED ALGAE carbonate after an incubation period in the field. An- Stiller, J. W., Riley, J. L., & Hall, B. D. nual growth rates averaged 1.8 mm yearϪ1 in L. marga- Departments of Genetics and Botany, University of ritae and 3.4 mm yearϪ1 in N. tricotomun, however, Washington, Seattle, WA 98195 USA growth rates varied seasonally. The photosynthetic response of both species as a function of temperature Whether red algae are the sister group to green plants was evaluated in the laboratory from 10Њ to 30Њ C. has been an intriguing question for over a century. Maximum net photosynthetic rates peaked at approx- We are investigating both the evolutionary and func- imately 25 to 30Њ C in both species, suggesting that tional significance of differences in DNA-dependent maximum growth rates occur during the warmest RNA polymerase II between rhodophytes and other months of the year. These results lead to a better un- eukaryotic organisms. Results of both phylogenetic derstanding of the biogeographic ranges of subtidal and genetic complementation studies are consistent coralline algae. with an origin of the Rhodophyta that was independent of the common ancestor of green plants, animals, fungi and several related protistan groups. Ex- 190 amination of long-branch attraction among Pol II SYMBIOTIC ORIGIN OF A NOVEL ACTIN gene sequences indicates that this separate emer- GENE IN THE CRYPTOPHYTE, PYRENOMO- gence of red algae is not the result of an artifactual NAS HELGOLANDII grouping of rhodophytes with more rapidly evolving Stibitz, T. B.1, Keeling, P. J.2, & Bhattacharya, D.1 taxa. The absence in red algal pol II largest subunits of a canonical C-terminal domain (CTD), an essential 1Department of Biological Sciences, University of Iowa, 2 component of mRNA transcription in plants, animals Iowa City, IA 52242 USA; Department of Botany, and fungi, further supports the proposition that red University of British Columbia, Vancouver, BC V6T algae diverged independently of these groups, and be- 1Z4 Canada fore CTD function was incorporated fully into Pol II function. Evolutionary complementation, that is, in Cryptophytes are photosynthetic protists that have ac- vivo replacement of the wild-type CTD from yeast with quired their plastids through the secondary symbiotic RPB1 C-terminal sequences from a red alga, further uptake of a red alga. A remarkable feature of crypto- supports the hypothesis that fundamental differences phytes is that they maintain a reduced form of the red exist in Pol II function between red algae and organ- algal nucleus, the nucleomorph, between the second isms with a CTD-based mRNA transcription cycle. and third plastid membranes (periplastidial compartment, PC). The nucleomorph is thought to be a tran- 192 sition state in the evolution of secondary plastids with BIOCHEMISTRY OF SILICA BIOMINERAL- this genome ultimately being lost (e.g., as in heterokonts, haptophytes, euglenophytes) when photosyn- IZATION IN DIATOMS thesis comes under full control of the “host” nucleus. Sumper, M. For this to happen, all genes for plastid function must Department of Biology, University of Regensburg, be transferred from the nucleomorph to the nucleus. 93040 Regensburg, Germany In this regard, it is generally assumed that nucleomorph genes with functions unrelated to plastid or Diatoms are well known for the intricate patterns of PC maintenance are lost. Surprisingly, we show here their silica-based cell walls. The complex structures of the existence of a novel type of actin gene in the host diatom cell walls are species specific and become pre- nucleus of the cryptophyte, Pyrenomonas helgolandii, cisely reproduced during each cell division cycle, indi- that has originated from the nucleomorph genome of cating a genetic control of silica biomineralization. the symbiont. Our results demonstrate for the first Therefore, the formation of the diatom cell wall has time that secondary symbionts can contribute genes been regarded as a paradigm for controlled produc- to the host lineage that are unrelated to plastid function of nanostructured silica. However, the mecha- PSA ABSTRACTS 65 nisms allowing biosilicification to proceed at ambient hole was prominent (O3 ϭ 170 Dobson units; DU ϭ temperature at high rates have remained enigmatic. 10-3 cm O3), and the other on a day with high ozone Recently, we have shown that a set of highly cationic concentration (O3 ϭ 328 DU). The decrease in ozone peptides (called silaffins) isolated from Cylindrotheca level would reduce productivity by 3–8%. Seasonal fusiformis shells are able to generate networks of silica variation of UVR has a bigger impact on cyanobacte- nanospheres within seconds when added to a solution rial productivity than ozone depletion. of silicic acid. Different silaffin species produce different morphologies of the precipitated silica. Silaffins 194 contain covalently modified Lys-Lys elements. One of ANALYSIS OF PORPHYRA RBCL DEMON- these lysine residues bears a novel type of protein STRATES MULTIPLE MIGRATIONS OC- modification, a polyamine consisting of 6–11 repeats of the N-methyl-propylamine unit. In addition to the CURRED BETWEEN THE NORTH ATLANTIC silaffins, additional polyamine-containing substances AND NORTH PACIFIC. have been isolated from a number of diatom species Teasdale, B. W.1, Lindstrom, S. C.2, Fredericq, that may be involved in the control of biosilica mor- S.3, Neefus, C. D1., Mathieson, A. C.1 Taylor, H.4 , phology. Scanning electron microscopic analysis of di- West, A.L.5, Mercado, S. T.4, Piche, N.4, & Klein, atom shells isolated in statu nascendi provide insights A. S.4,5 into the processes of pattern formation in biosilica. A 1Department of Plant Biology, University of New model will be discussed that explains production of Hampshire, Durham NH 03824 USA; 2 Department of nanostructured biosilica in diatoms on the basis of Botany, University of British Columbia, Vancouver, these experimental results. B.C. V6T 1Z4 Canada; 3Department of Biology, P.O. Box 42451 University of Louisiana at Lafayette Lafay- 4 193 ette LA 70504 USA; Department of Biochemistry and- Molecular Biology, University of New Hampshire, EFFECTS OF INCREASING UV-B RADIATION Durham NH 03824 USA; 5Genetics Program, Univer- DUE TO OZONE DEPLETION ON PHOTO- sity of New Hampshire, Durham NH 03824 USA SYNTHESIS OF ANTARCTIC CYANOBAC- TERIA The taxonomic and evolutionary relationships be- Tang, E. P. Y., Neale, P. J. & Fritz, J. J. tween Porphyra of the boreal North Pacific (NP) and Smithsonian Environmental Research Center, P. O. North Atlantic (NA) are being examined using near Box 28, Edgewater, MD 21037 USA full length sequences of rbcL and the rbcL rbcS spacer bp). Phylogenetic analysis of Ͼ20 recognized 1420ف) Ground level ultraviolet-B (UV-B; 290–320 nm) fluxes species produced clusters containing both NP and NA in Antarctica have been increasing due to strato- species: Porphyra carolinenesis (NA) and Porphyra perfo- spheric ozone depletion. Although mat-forming cy- rata (NP); Porphyra. leucosticta (NA) and Porphyra fuci- anobacteria are major component of freshwater algal cola (NP); Porphyra ‘amplissima’ (NA) and Porphyra cu- biomass in Antarctica, little is known about their re- neiformis (NP); Porphyra ‘umbilicalis’ (NA) and Porphyra sponse to increasing ultraviolet radiation (UVR). The mumfordii (NP). A cluster of NP species including Por- present study evaluated the sensitivity to UVR of two phyra abbottae, Porphyra kurogii, Porphyra pseudolinearis, strains of mat-forming cyanobacteria with different and Porphyra pseudolanceolata formed a sister clade to cell size, Phormidium murrayi (6.0 x 3.2 ␮m) and Schizo- P. fucicola (NP), P. leucosticta (NA) and several cryptic thrix calcicola (2.2 x 2.3 ␮m). Cyanobacterial photosyn- NA taxa. These results demonstrate that a number of thesis was measured under different UV spectral qual- “independent” migrations occurred between the ity and quantity achieved by polychromatic filters with North Pacific and Northern Atlantic. Furthermore different cutoff wavelengths and neutral density these results confirm the hypothesis, based on similar- screens. The productivity and irradiance data were ities in morphology, isozymes, and karyotype, of Lind- used to generate biological weighting functions strom & Cole (1992), that several sibling species pairs (BWF) for the assessment of UV inhibition on photo- exist for Porphyra of the boreal North Pacific (NP) and synthesis. The kinetics of UV inhibition, as deter- North Atlantic (NA). mined by PAM fluorometry, differed between the two species so that inhibition of P. murrayi and S. calcicola 195 were modeled based on UV-irradiance and cumula- LIGHT REGULATION OF PHYCOBILISOME tive exposure, respectively. After a one hour exposure, BWF’s did not differ between the two isolates of BIOSYNTHESIS AND CONTROL BY A PHY- cyanobacteria despite their differences in cell size. To TOCHROME-LIKE PHOTORECEPTOR 1 1 2 evaluate the negative impact of increased UV-B expo- Terauchi, K. , Ort, L. , Grossman, A. R. , & sure due to ozone depletion on cyanobacteria, the Kehoe, D. M.1 BWF’s were applied to two solar spectra obtained 1Department of Biology, A413 Jordan Hall, 1001 East from McMurdo Station, one on a day when the ozone Third Street, Indiana University, Bloomington, IN 66 PSA ABSTRACTS

47405 USA; 2Department of Plant Biology, Carnegie diatoms to other stramenopiles. According to most Institution of Washington, 290 Panama Street, Stan- claims based on morphological data, typically viewed ford, CA 94305 USA from a non-rigorous evolutionary taxonomy stand- point (i.e. not with explicit cladistic or phylogenetic Ambient light quality changes dramatically affect the systematic methodology), diatoms are closely related composition of light harvesting structures, the phyco- to silica-scaled golden brown algae (chrysophytes or bilisomes, in many cyanobacterial species. In the cy- synurophytes). SSU rDNA sequence data, however, of- anobacterium Fremyella diplosiphon, shifts in the ratio ten place diatoms at the base of the heterokont alga of red to green light lead to transcriptional changes tree, and chryso/synurophytes at the tip with eustig- and altered synthesis of several phycobilisome compo- matophytes, for example, as the chryso/synurophyte nents. This process is called complementary chro- sister group. More recent analysis of rbcL sequences, matic adaptation (CCA). These two colors have oppo- however, supports the traditional classification. It is site effects: red light activates an operon encoding the not automatically to be assumed that there is incon- biliprotein phycocyanin (PC) and inactivates the op- gruence between the sequences, however. Taxon sam- eron encoding phycoerythrin (PE), whereas green pling is different in the different analyses, methods of light activates PE synthesis and shuts down PC synthe- analysis are often different, assumptions used to “fil- sis. The effects of red and green light on CCA are ter” data are different, etc. Moreover, the relative photoreversible. Thus, CCA is similar to transcrip- strength of signal appears to be different in the data tional processes that are controlled by phytochromes, sets. We will present an analysis of combined SSU, a family of eukaryotic red/far red photoreversible rbcL and coxI data, an analysis of taxon-sampling is- photoreceptors. We are using molecular genetics to sues, and review underlying assumptions and method- determine the mechanisms by which F. diplosiphon ologies in an attempt to a) better understand the re- senses changes in the color of light of its environ- sults of prior studies and b) reconcile the different ment. Initial mutant generation and complementa- hypotheses. tion lead to the discovery of three CCA regulatory components that are part of a complex two component system. The most interesting of these is RcaE 197 (regulator of chromatic adaptation), a histidine ki- PHYLOGENETIC RELATIONSHIPS OF GELID- nase-class protein containing a region in its amino-ter- IALES SPECIES IN COSTA RICA minal half with similarity to the chromophore binding Thomas, D. T. & Freshwater, D. W. domains of phytochromes. Within this region, RcaE Center for Marine Science, University of North Caro- contains a cysteine residue in a similar location as that lina at Wilmington, 1 Marvin Moss Lane, Wilming- used for covalent attachment of the open-chain tet- ton, NC 28409 rapyrrole chromophore in phytochromes. We will present recent data characterizing RcaE, including in Despite a general paucity of studies on marine algae vivo analysis of the chromophore that is attached to in Costa Rica, within the red algal order Gelidiales, 9 RcaE, as well as results from our recent isolation of a species are reported from the Caribbean, and 6 spe- new CCA regulatory component. cies from the Pacific. In this study 5 species from the southeast Caribbean coast and 2 species from the 196 northwest Pacific coast of Costa Rica were collected WHAT DOES COMBINING MOLECULAR DATA for DNA sequence and morphological analyses. At the SETS TELL US ABOUT DIATOM ORIGINS time of this writing, morphological observations of AND PHYLOGENY? four Caribbean taxa have identified them as Gelidium Theriot, E. C.1 & Goertzen, L.2 microdonticum, Pterocladiella capillacea, P. melanoidea, 1 and Gelidiella acerosa. In rbcL sequence analyses, Gelid- Texas Memorial Museum, 2400 Trinity Street, Uni- ium microdonticum is resolved within a clade of small 2 versity of Texas, Austin, TX 78705 USA; Section of Gelidium species predominantly found in the south At- Integrative Biology, University of Texas, Austin, TX lantic. Two collections representing different forms of 78712 USA Pterocladiella melanoidea sensu Dawson were found to have identical rbcL sequences. These samples were re- The past several years have seen an abundance of mo- solved in rbcL trees with a taxon from Texas identified lecular sequence data gathered on heterokont algae as P. bartlettii and not P. melanoidea from Europe. Com- and other stramenopiles with the goal of resolving parisons with type material are being made to verify phylogenetic relationships among major groups. The these identifications so that the status of P. melanoidea original focus was on SSU rDNA sequence, but lately a in the Caribbean may be determined. The unidenti- significant number of sequences of plastid and mito- fied Caribbean taxon is resolved as a distinct species chondrial encoded genes (specifically rbcL and coxI) within the Pterocladiella clade as well. Gelidiella acerosa have been made available. Of particular interest to us from Caribbean Costa Rica is closely allied with other has been the origin of diatoms and the relationship of Caribbean G. acerosa samples in rbcL trees. The two pa- PSA ABSTRACTS 67 cific taxa are small intertidal turf species and have not with the colonial rotifer Conochilus unicornis. We do yet been identified. Sequence analyses resolve these not know if either organism benefits or is harmed in taxa within a large clade of Indo-Pacific and Carib- this relationship. For example, while we’ve seen the bean Gelidium species. rotifers of the colony ingest other algae, we have not seen predation of the E. agilis (neither those embedded in the mucilaginous secretions of the rotifer nor swimming outside of the colony). This association is interesting for several reasons: 1) E. agilis is normally 198 free-living. 2) There are few known symbiotic relation- DIATOMS AS HOSTS FOR OTHER DIATOMS: ships between euglenoids and rotifers. 3) E. agilis lose OBSERVATIONS FROM SOUTHERN CALI- their long single flagellum when in the colony. We FORNIA plan to use light and electron microscopy to investi- Tiffany, M. A.1, & Lange, C. B.2 gate the ultrastructure of the E. agilis and its relation- 1Department of Biology, San Diego State University, ship to the rotifer colony. San Diego, CA 92128 USA; 2Scripps Institution of Oceanography, La Jolla, CA 92093-0244 USA 200 Large epiphytic and epilithic diatom species hosting other diatoms were observed in several fresh- and EVIDENCE FOR GLUCAN COMPONENTS IN brackish water sites in Southern California. The most THE PRIMARY ZYGOTE WALL OF CHLAMY- commonly encountered hosts were species forming DOMONAS MONOICA long filaments attached to rocks or macroalgae, Hy- VanWinkle-Swift, K. P., Salanga, M. C., Thompson, drosera whampoensis (Schwarz) Hendey, Melosira vari- E. G., Bai, M. S., & Parish, E. W. ans Agardh, Pleurosira laevis (Ehrenberg) Compere Department of Biological Sciences, Northern Arizona and Terpsinoe musica Ehrenberg. These large diatoms University, Flagstaff, AZ 86011 often had smaller diatoms attached, usually to the gir- dle bands and occasionally to the mucilage pads con- The primary zygote wall of C. monoica is transient and necting the cells. For example, cells of T. musica were is released from mature zygospores. The fluoro- observed supporting growth of a diverse diatom as- chromes aniline blue and primulin, used in other sys- semblage composed of species of the genera Achnan- tems to detect ␤-1,3 glucans, stain the primary wall in- thes, Achnanthidium, Amphora, Cocconeis and Tabularia; tensely. Two ␤-1,3 glucan synthases have been Synedra sp. was attached to M. varians and B. paxillifer; identified in higher plants: a calcium-dependent syn- and Cocconeis placentula was seen on H. whampoensis. thase produced in response to wounding and induced Thus, large epiphytic and epilithic diatoms seem to by chitosan, and a magnesium-dependent enzyme, as- provide suitable sites for attachment of small epi- sociated with pollen development and unresponsive phytic diatom species, and it appears that this phe- to chitosan. Chitosan has no effect on C. monoica pri- nomenon is more common than previously thought. mary wall synthesis or staining properties. We are presently testing for the effect of magnesium and/or calcium depletion on primary wall synthesis. Aniline blue and primulin do not stain purified cellulose fi- 199 bers, while the fluorochrome Calcofluor does. Calcof- luor also stains the primary wall intensely. For all fluo- ASSOCIATION OF A FREE-LIVING EUGLENA rochormes tested, fluorescence is first detected in WITH A COLONIAL ROTIFER motile quadriflagellate zygotes. Aniline blue staining Uzwiak, D. J. & Triemer, R. E. maximizes quickly, while Calcofluor staining contin- Division of Life Sciences, Rutgers University, Piscat- ues to intensify until primary wall release. Dinitroben- away, NJ 08854 USA zonitrile, a specific inhibitor of cellulose synthesis in plants, has no effect on primary wall synthesis in C. Euglena agilis (syn. Euglena pisciformis) is a free-living monoica. Addition of glucanase or cellulase to partially euglenoid found in brackish or fresh water. This spe- purified primary walls results in wall thinning and loss cies can be identified by its fusiform shape, single of staining. Using electron microscopy, we are evaluat- long flagellum, and prominent anterior eyespot. It ing the effects of these enzymes on primary wall ultra- can be distinguished from other euglenoids in part by structure. Further studies are needed to determine its two to three large chloroplasts that run parallel to whether all three fluorochromes are recognizing the the length of the body, each with a single pyrenoid same polysaccharide component (a ␤-1,3 glucan or a capped on two sides by paramylon. Euglena agilis is ␤-1,3; ␤-1,4 mixed glucan), or whether Calcofluor commonly found in our collecting ponds in central staining indicates the presence of a distinct compo- New Jersey. In two consecutive summers, we have nent containing ␤-1,4 linkages, such as cellulose or a found large numbers of these cells living symbiotically xyloglucan. 68 PSA ABSTRACTS

201 rubisco large subunit gene (rbcL) and the ribosomal SURVEY OF BENTHIC DIATOM COMMUNI- DNA internal transcribed spacers (ITS1 & 2) were se- TIES FROM LOTIC SYSTEMS WITHIN THE quenced. Morphometic results showed individuals WESTERN ALLEGHENY PLATEAU from the various locations to be morphologically uni- form with little variation in pertinent characters. In Verb, R. G. & Vis, M. L. the analysis of the rbcL data, samples from Connecti- Department of Environmental & Plant Biology, Ohio cut, Ohio, Louisiana, North Carolina and Indiana University, Athens, OH 45701 USA were identical in sequence and the Rhode Island and Massachusetts samples were most derived. The Michi- Over the course of 3 years (1997–1999), 72 stream gan and Tennessee samples were closely related to sites were sampled for epilithic diatom communities. each other but not the other samples. For the ITS The analysis of these samples has led to the identifica- data, the tree topology was similar to that obtained tion of over 325 species of diatoms. In addition to with the rbcL data. In comparison with rbcL, sequence sampling the diatom community, selected physical variation in the ITS region among samples was and chemical parameters were recorded from each greater and showed more resolution among the stream reach. These parameters included pH, specific stream sites. In terms of biogeography, three geo- conductance, current velocity, SRP, nitrate, silica, and graphically close samples (Connecticut, Rhode Is- total alkalinity. Canonical Correspondence Analysis land, Massachusetts) were most closely related. How- (CCA) was used to identify influential environmental ever, genetic relationships did not necessarily reflect parameters and to assess the response of the diatom geographic distance. For example, two distant popula- community to prominent anthropogenic inputs in the tions, Louisiana and Indiana, were most closely re- region (i.e. coal mine drainage, eutrophication). The lated. Variation in ITS sequence data among individu- initial analyses indicate that pH was the most influen- als from a single stream site will be discussed. tial environmental parameter along the first CCA axis. This shift was not unexpected, as acid mine drainage (AMD) in the region leads to a wide range of pH values (2.8–7.93). The highly acidic sites were character- 203 ized by species of the genus Eunotia (specifically E. ex- THE PHYLOGENETICS OF ACROCHA- igua and E. steineckei), Frustulia rhomboides, and Pinnularia ETIALES REVISITED: INFERENCES FROM subcapitata. Furthermore, Achnanthidium minutissimum RBCL AND CHLOROPLAST ENCODED 23S was the most widely distributed of the diatom species RRNA SEQUENCE ANALYSIS encountered, being found at 94% of the sites sam- Volovsek, M. E.1, Hommersand, M. H.1, & pled. Streams that fluctuated between acidic and cir- 2 cumneutral pH (termed “teeter-totter”) had greater Manos, P. 1 abundances of Brachysira vitrea than other streams in Department of Biology, University of North Carolina, this survey. Further implications for the use of these Coker Hall, Chapel Hill, NC 27599 USA; 2Department diatom communities as biomonitoring tools and the of Botany, Duke University, Durham, NC 27708 USA distribution of assemblages within the Western Al- legheny Plateau will be discussed. Recent molecular evidence from 23S rRNA sequences has shed light on the phylogenetic status of Acrocha- etiales and Palmariales, suggesting a paraphyletic Ac- rochaetiales and a monophyletic Palmariales-Acrocha- 202 etiales assemblage characterized by the absence of BIOGEOGRAPHY OF BATRACHOSPERMUM both the carpogonial filament and associated post-fer- HELMENTOSUM (BATRACHOSPERMALES, tilization fusions. It has also brought into question the RHODOPHYTA) IN NORTH AMERICA USING status of Palmariales. Despite these findings, the fa- milial and generic systematics of Acrochaetiales have MOLECULAR AND MORPHOLOGICAL DATA remained somewhat obscure, in large part due to in- Vis, M. L., Miller, E. J., & Hall, M. M. adequate taxon and gene sampling. In the present Department of Environmental & Plant Biology, Ohio study we address this problem by performing phyloge- University, Athens, OH 45701 USA netic analyses of rbcL and 23S rRNA sequences from acrochaetioid algae covering a broad range of mor- Twelve collections of the freshwater red alga Batracho- phologies. Our results confirm elements from several spermum helmentosum were investigated using molecu- primarily chloroplast based classification schemes lar sequence and morphological data. Collections (Papenfuss 1945, 1947; Stegenga 1979, 1985; Lee & were from streams throughout the range of this spe- Lee 1988) while also providing new phylogenetics in- cies in North America, from Louisiana and Tennessee sight. Two groups are supported at the most inclusive in the south to Michigan and Massachusetts in the level. Group I is marine, has parietal chloroplasts, and north. Eleven morphometric characters were mea- includes three clades delimited primarily by the pres- sured for each of the specimens sequenced. Both the ence/absence of pyrenoids, number of chloroplasts, PSA ABSTRACTS 69 and possibly spore germination pattern. Group II is 205 more heterogeneous and consists of three clades dif- TEMPERATURE INDUCED PHOTOINHIBI- ferentiated largely by chloroplast type (stellate/pari- TION IN OUTDOOR CULTURES OF MONO- etal, pyrenoid present/absent) and number, habitat DUS SUBTERRANEUS (marine/freshwater) and life history. Systematic crite- 1 2 1 ria drawn from the closely related order Palmariales Vonshak A. , Torzillo, G. , & Boussiba S. 1 suggest that we recognize Group I as a new family, Co- Microalgal Biotechnology Laboratory, The Jacob laconemataceae, and the three taxa in Group II as Ac- Blaustein Institute for Desert Research, Ben-Gurion rochaetiaceae, Rhodochortonaceae and Audouinel- University of the Negev, Sede Boker Campus 84990, Is- laceae. Furthermore, each of the three groups in rael; 2Centro di Studio dei Microrganismi Autotrofi del Colaconemataceae could be regarded at the generic CNR, Firenze, Italy level. We also report on the utility of 23S rRNA for red algal systematics. Outdoor algal cultures are continuously exposed to changes in environmental conditions, particularly irradiance and temperature. While the changes in light intensity take place in a range of one to two hours, the 204 increase in temperature is a slower process and takes THE ROLE OF CALCIUM IN FLOW-STIMU- about four to five hours. This de-synchronization be- LATED BIOLUMINESCENCE OF THE RED tween the two important environmental factors gov- TIDE DINOFLAGELLATE LINGULODINIUM erning photosynthesis and growth of algae results in a POLYEDRUM unique stress condition where photoinhibition can be von Dassow, P., & Latz, M. I. induced at relatively low light intensity. Outdoors the early morning culture temperature was found to be Scripps Institution of Oceanography, University of Cal- about 12 to 14Њ C, and reaches 25 to 28Њ C at mid-day. ifornia San Diego, La Jolla, CA 92093 USA In an experiment, such a natural temperature regime was compared to another one in which the morning Many marine planktonic dinoflagellates emit flashes temperature of the culture was increased to 20Њ C by of light in response to either laminar or turbulent using a heating system. A fast decline in the maximal flows as well as direct mechanical stimulation. The photochemical efficiency of PSII (Fv/Fm) was ob- production of a flash of light is known to be mediated served starting as soon as sunrise. The decline was by a proton-mediated action potential across the vacu- faster in the non-heated culture and was to a lower olar membrane; the mechanotransduction process value. The diurnal changes in the electron transfer initiating this action potential is unknown. Here we rate (ETR) and in the non-photochemical quenching ϩ report on an investigation into the role of Ca 2 in the (NPQ) of the cultures, indicated that the early morn- mechanotransduction process regulating biolumines- ing exposure of cells to sub-optimal temperature re- cence in the red tide dinoflagellate Lingulodinium poly- sults in a fast inactivation of PSII activity which was re- edrum. Calcium ionophores and low concentrations of flected in an inhibition of the photosynthetic activity the membrane-disrupting agent digitonin stimulated even when the two cultures finally reached the same bioluminescence only when calcium was present in temperature at mid-day. Thus, under the same light the media or added with the agent, indicating that the and temperature mid-day conditions the ETR was flash-triggering vacuolar action potential is specifi- higher and the NPQ was significantly lower in the cally stimulated by a calcium influx. A variety of heated culture. Significant changes in productivity of known calcium channel blockers or antagonists inhib- the cultures also were observed. ited mechanically stimulated bioluminescence but did not affect cellular bioluminescent capacity. In many cases the inhibitory affect occurred after only a brief 206 exposure. In addition, gadolinium (Gdϩ3), a blocker FUCUS VANADIUM PEROXIDASE: MINIMUM of many stretch-activated ion channels, caused potent CATALYTIC DOMAIN SIZE RETAINING PER- inhibition of mechanically stimulated biolumines- OXIDASE ACTIVITY cence. The order of potency of the transition metals Vreeland, V. J., Ly, L. S., Riebe, J. L. Sabatier, C. tested was Laϩ3 Ͼ Gdϩ3 Ͼ Coϩ2 Ͼ Mnϩ2 Ͼ Niϩ2, similar to their potency as blockers of known calcium & McCoy, S. I. channels. Experiments with a quantified shear flow Materials Sciences Division, Lawrence Berkeley Na- demonstrated that flow-stimulated bioluminescence tional Laboratory, MS 66, 1 Cyclotron Road, Berkeley, depended on the level of extracellular calcium. Fu- CA 94720 USA ture work will elucidate the signaling pathway involving calcium-mediated flow-stimulated mechanotrans- Vanadium peroxidase catalyzes the extracellular as- duction. Our goal is to use bioluminescence as a sembly of Fucus zygote cell surface adhesive (Vreeland proxy for the initial cellular mechanotransduction & Epstein 1996, Modern Meth. Plant Anal. 17, 95–116). events triggered by fluid flow. Our goal is to identify the catalytic, self-associating 70 PSA ABSTRACTS and wall targeting functional domains of algal vana- Overall, two pore regions were recognized that were dium peroxidase to understand its role in algal common to the silica of all samples: the smallest (d propagule adhesion. As a first step, we truncated our less than 10 nm) regularly spaced and shaped spheri- recombinant Fucus vanadium peroxidase (GenBank cally, the larger (up to 65 nm) being cylinders or slits. AF053411) for catalytic domain identification. Re- Apparently, at a nanoscale level diatomaceous silica is combinant constructs were prepared which re- quite homologous among species, in agreement with duced the C-terminal catalytic domain at either or the chemical principles of silica polymerization under ‚oth N- and C-terminal ends. Recombinant proteins the conditions of pH and precursor concentrations in- were expressed in E. coli, refolded from cytoplasm and side the silicon deposition vesicle. The final frustule inclusion ‚odies and tested for vanadium-specific o- “macro”-morphology is of course species-specific, dianisidine peroxidase activity. Preliminary results being determined genetically. Synthetically-derived demonstrated peroxidase activity when the 40 kDa MCM-type silicas have a similarly organized pore dis- catalytic domain was truncated on ‚oth ends to 24 tribution in an amorphous silica matrix as we found kDa. Further terminal and internal truncation is in all diatom species studied. We therefore suggest needed to fully define the minimal catalytic unit, that organic molecules of a kind used as structure-direct- which could be as small as 15–20 kDa within the 73 ing agents to produce these artificial silicas play a role kDa monomer. The very small catalytic unit in Fucus in the nucleation of the silica polymerization reaction vanadium peroxidase is not unexpected considering and the shaping of pore morphology inside the sili- the rigid ‚undled helical vanadate frame in the Cur- con deposition vesicle of diatoms. Structure-directing vularia fungal vanadium peroxidase (Macedo-Ribeiro molecules now await isolation from the SDV, followed et al. 1999, J. Biol. Inorg. Chem. 4, 209–219). We con- by identification and characterisation by molecular clude that interactions ‚etween the N-terminal non- techniques. catalytic domain and the C-terminal catalytic domain, found in the crystalline Ascophyllum enzyme (Weyland 208 et al. 1999, J. Mol. Biol. 293, 595–611), are unnecessary A REASSESSMENT OF ITS/5.8S DNA SE- for peroxidase activity. Other conserved amino acids QUENCE VARIATION AND PHYLOGENETIC in the C-terminal half of Fucus vanadium peroxidase, peripheral to the helical core, could participate in SIGNAL IN THE SYNUROPHYCEAE protein surface functions such self-association and Wee, J. L. wall targeting. Department of Biological Sciences, Loyola University, New Orleans, LA 70118 USA

207 Previously, DNA sequences were determined for the DIATOM SILICA BIOMINERALIZATION: AT entire ITS/5.8S region by direct sequencing of PCR NANOSCALE LEVEL A CHEMICALLY UNI- amplification products. 28 sequences were obtained FORM PROCESS from 12 species of Synurophyceae, including Tessellaria Vrieling, E. G.1, Gieskes, W. W. C.1, Beelen, T. P. M.2, volvocina, Chrysodidymus synuroideus, six species of Syn- & van Santen, R. A.2 ura and four species of Mallomonas. Sequences also 1Department of marine Biology, University of Gronin- were determined from multiple strains of some species, including 15 strains of Synura petersenii. The gen, P.O. Box 14, NL-9750 AA Haren, The Nether- 2 length of these sequences varied from 495–598 bp. lands; Schuit Institute of Catalysis, Eindhoven Uni- The large amount of ITS/5.8S length variation made versity of Technology, P.O. Box 513, NL-6500 MB, initial attempts in determining reliable sequence The Netherlands alignment difficult and precluded their use in phylogenetic analyses of the class. Subsequently, the ap- Using a high-brilliance synchrotron X-ray source, proach of Bogler & Simpson (1996) was investigated combined small- and wide-angle X-ray scattering where reiterative, computer assisted alignments were (SAXS and WAXS) was applied to study nanoscale generated and the quality of the alignment was evalu- characteristics, in particular pore size in the range of ated ‚y homoplasy index and consistency index val- 3 to 65 nm, of a variety of unialgal cultures of centric ues. However, these alignments also were equivocal. and pennate diatoms, and of mixed diatom popula- ITS/5.8S sequences sorted the 15 S. petersenii strains tions sampled in the field. Results of scattering analy- into two well supported ITS lineages. One ITS type in- sis were compared with details of pore size, structure cluded ten isolates from North America while isolates and orientation visible at the electron microscopic from the second ITS type included one each from level. WAXS patterns did not reveal any crystalline Germany and Australia and three from North Amer- phase or features of microcrystallinity (resolution 0.07 ica. Results are presented here where the sequences to 0.51 nm), which implies a totally amorphous char- from the 15 S. petersenii isolates were used to charac- acter of the SiO2 matrix of the frustule material. SAXS terize ITS-1 and ITS-2 RNA transcript secondary struc- data (resolution 3 to 65 nm) provided information on ture. Next, this information was expanded to include geometry, size, and distribution of pores in the silica. ITS/5.8S sequences from the other taxa in the class. PSA ABSTRACTS 71

Finally, the characteristics of ITS 1 and ITS 2 RNA use of this cyanobacteria specific marker and primers transcript secondary structure were used as a guide to allowed us to amplify cpcBA-IGS DNA from uni-cy- align all of the ITS/5.8S sequences from the Synuro- anobacterial field samples. The morphology and phyceae in a final phylogenetic analysis. habit of specimens were documented by photomicros- copy. Single filaments or colonies of field material 209 and 3–4 filaments of culture material were then amplified using the polymerase chain reaction (PCR). BIOGEOGRAPHY OF ASEXUAL AND SEXUAL Results include analysis of non-toxic summer and REPRODUCTION IN CALOGLOSSA (DELES- toxic winter blooms of Anabaena from 1989–1997 in SERIACEAE, RHODOPHYTA) FROM AUS- American Lake, WA and a comparison of non-toxic TRALIA AND NEW ZEALAND and toxic Microcystis from Lake Sammamish, WA. A West, J.1, M. Kamiya2 & G. Zuccarello3 preliminary phylogenetics analysis of Pacific North- The School of Botany, University of Melbourne, west and UTEX isolates also was performed using par- Parkville Victoria 3052, Australia; 2Kobe University simony, maximum likelihood and distance methods. Center for Inland Seas, Iwaya, Awaji-cho, 656-2401 The results of this analysis suggest that revision of Japan; 3School of Biological Sciences, University of New Anabaena and Microcystis taxonomy may be needed. South Wales, Sydney 2052, Australia 211 Caloglossa species are widely distributed in mangroves MECHANISMS CONTROLLING NUCLEAR and salt marshes around the world and their life history MIGRATION ALONG THE TRICHOGYNE IN patterns are being investigated in laboratory culture. THE RED ALGA, BOSTRYCHIA MORITZIANA In Australia all isolates of C. monosticha, C. postiae and (RHODOMELACEAE, RHODOPHYTA) C. ogasawaraensis have Polysiphonia-type (P-type) sexual Wilson, S. M., Pickett-Heaps, J. D., & West, J. A life histories. Among the 70 C. leprieurii isolates from The School of Botany, University of Melbourne, Australia and New Zealand P-type sexual reproduc- Parkville 3010, Victoria AUSTRALIA tion also is dominant. However, ten isolates of C. leprieurii from the Spencer Gulf and the Gulf of St. Vincent Sexual reproduction in red algae has been studied for in South Australia give rise to successive tetraspor- over a century primarily for taxonomic purposes. De- phyte generations without gametophytes. Moreover, spite this interest, only recently have the critical one isolate from Queensland is asexual. Only one South events of fertilisation been revealed. Time-lapse video Australia isolate, obtained from Lake Alexandrina at microscopy techniques have been used to document the mouth of the Murray River, is sexual. South Austra- the stages in the fertilization process within Bostrychia lia and Pacific Mexico are two regions in which asex- moritziana. Once plasmogamy between a trichogyne ual reproduction is dominant. In another mangrove and spermatium is achieved, two differentiated male dwelling red alga Bostrychia moritiziana (Rhodomelaceae) nuclei may enter the trichogyne. One of the two mi- non-sexual reproduction also is frequent in Australia, grates to the carpogonium while the other travels in New Caledonia and Bali (Indonesia). This asexual re- the opposite direction towards the trichogyne tip and productive pattern of tetrasporophytic recycling ap- plays no further role in fertilisation. The precise pears to have arisen independently among individual mechanism governing this bidirectional movement of populations of various red algal species in different male nuclei is unknown, but the cytoskeleton is be- regions. Investigations are underway on the molecular lieved to be involved. Fluorescent staining and confo- phylogeny of the Caloglossa leprieurii isolates. cal microscopy shows an extensive arrangement of actin filaments in spermatia and along trichogynes yet 210 microtubules are only evident in dividing spermatia. ANABAENA AND MICROCYSTIS IN THE PACIFIC Actin filaments appear to be involved in plasmogamy NORTHWEST: A TALE OF PLASTICITY and ensheath male nuclei as they migrate from the Williams, C. R., Peters, B. & Waaland, J. R. spermatium and as they travel along the trichogyne in either direction. Drug-inhibition studies and UV- Department of Botany, Box 355325, University of microbeam irradiation indicate nuclear migration Washington, Seattle, WA 98195 USA along trichogynes is actin/myosin dependent

The molecular marker, cpcBA-IGS, was used to exam- 212 ine the biogeography of representatives of Anabaena and Microcystis collected from Pacific Northwest lakes MITOSIS, CELL WALL AND FLAGELLA SYN- and their phylogenetic relationship to isolates from THESIS IN SYNCHRONIZED CULTURES OF the UTEX and CCAP culture collections. cpcBA-IGS THE PRASINOPHYTE, SCHERFFELIA DUBIA contains portions of the alpha and beta subunit of cy- Wustman, B. A., Becker, B., & Melkonian, M. anophycocyanin with an intergenic spacer (IGS) of Botanical Institute, University of Cologne, 50931 Co- base pairs situated between the subunits. The logne, Germany 100ف 72 PSA ABSTRACTS

Cell division occurs within the parental cell wall, yield- lection is identified and previous records are incorpo- ing two progeny cells. Since Scherffelia dubia sheds all rated. Aspects of biogeography will be discussed in four flagella prior to cell division, the maturing prog- light of such extraordinary diversity over a relatively eny cells must regenerate new cell walls and flagella confined region. during and/or after cytokinesis. To better understand these processes, we have synchronized cell division in 214 cultures of S. dubia and observed all stages of mitosis, IN SITU GROWTH AND REPRODUCTION OF cytokinesis, and progeny cell maturation, including flagella and cell wall formation, via DAPI staining of PORPHYRA PERFORATA IN THE PACIFIC fixed cells, DIC microscopy of live cells embedded in COAST OF BAJA CALIFORNIA 1 1 agarose and standard TEM. Microscopical observa- Zertuche-Gonzalez, J. A. , Pacheco-Ruiz, I. , Cabello- tions revealed the following sequence of events: 1) Pasini, A.1, Chee-Barragan, A.1, Guzman, J. M.1 Golgi stacks divide during late interphase and imme- Galvez, A.1 & Arroyo, E.1, Yarish, C.2 diately begin producing theca scales; 2) deflagellation 1Instituto de Investigaciones Oceanologicas, Univer- and release of the parental cell wall from the plasma sidad Autonoma de Baja California. PO Box 453, membrane occurs during early prophase; 3) synthesis Ensenada, 22860 Mexico; 2University of Connecticut, of theca and flagella scales within the Golgi and/or One University Place, Stamford, CT 06901-2315, scale reticulum continues throughout mitosis; 4) dur- USA ing cytokinesis, a coalescence of vesicles containing theca scales at the posterior end of the cell results in a Porphyra perforata is a common species off the Pacific cleavage furrow slightly diagonal to the cells’ longitu- coast of Baja California peninsula. In situ growth, phe- dinal axis (40 min); 5) post-mitotic nascent basal body nology and reproductive characteristic of this plant formation and flagella elongation at the inherited are being determined in order to evaluate the feasibil- basal bodies (and later at the mature nascent basal ity of its culture in open water conditions. Contrary to bodies) occurs concurrently with continued cell wall previous studies that describe this species as ephym- synthesis; 6) the cleavage furrow rotates into a trans- eral, P. perforata is present all year around off the verse position (35 min); 7) reorientation of the nuclei north coast of the Baja California peninsula. Its verti- results in a “head to tail” orientation of the maturing cal distribution is limited to a band, ϩ50 to ϩ150 cm progeny cells; and 8) matured progeny cells emerge above sea level. However, subtidal growth transplant from the posterior end of the parental theca not be- experiments showed that the plants are capable of fore 8 hrs after the onset of mitosis. growing down to a depth of 5 m. Highest growth rates were observed from February to July, then tissue was 213 lost as a consequence of sexual reproduction. Biomass continues to decreases for the rest of the year. About MARINE MACROALGAL DIVERSITY IN THE 50% of the plants were reproductive by May and more REPUBLIC OF PANAMA than 90% by August. Oysters shells were introduced Wysor, B.1, Kooistra, W. H. C. F.2, Fredericq, S.1 and collected every month to evaluate the presence of 1The University of Louisiana at Lafayette, Department chonchocelis phase and P. perforata recruitment. of Biology, PO Box 42451, Lafayette, LA 70504 USA; Chonchocelis was observed all year and new recruits 2Mariene Biologie, Biologisch Centrum Postbus 14, were present from September to February. These re- 9750 AA Haren (GN), The Netherlands sults suggest that the foliar phase P. perforata could be cultured in the ocean for about six months of the year The marine flora of Panama remains poorly de- and could be culture subtidally. scribed to date, having been described from a few spo- radic and species poor (Ͻ50 species) collections in 215 the early half of the century and a couple of dedicated CONFIRMATION OF CATFISH MORTALI- surveys in the latter half. With the exception of a few TIES RESULTING FROM MICROCYSTIN PRO- studies that have focused on particular genera or spe- DUCED DURING MICROCYSTIS BLOOMS cies, only a single marine floral survey has been pub- Zimba, P. V.1, Khoo, L.1, Carmichael, W. W.2, & lished in the past three decades. In 1999 we collected Gaunt, P.1 marine algae from nearly 100 different collection sites 1Thad Cochran National Warmwater Research Center, along both coasts of Panama over a 10 month period U. S. Department of Agriculture, Agricultural Research of time. Over 1500 specimens have been curated, rep- 2 resenting 250 Caribbean species and 117 Pacific spe- Service, Stoneville, MS 38776 USA; Department of Bi- cies. This is an increase in algal diversity of approxi- ological Sciences, University of Dayton, Dayton, OH mately 100 and 50% for the Caribbean and Pacific 05435 USA flora, respectively, relative to Earle’s compilation of 1972. We estimate that algal diversity in Panama may Enigmatic deaths of finfish have occurred in freshwa- approach 450 species as the remaining 30% of the col- ter systems for many years. Some of these fish mortali- PSA ABSTRACTS 73 ties can be attributed to the accumulation of cyano- emerged through the neck of the lorica. The released bacterial toxins during ingestion of floating feeds or cells could easily be mistaken for Euglena species. passively through opercular ventilation. We recently were able to document the accumulation of microcys- 217 tin and resulting catastrophic mortality of pond-raised FIVE CRYPTIC SPECIES OF PORPHYRA FROM catfish (Ictalurus punctatus). The causative organism, THE NORTHWEST ATLANTIC Microcystis aeruginosa, was the dominant phytoplank- 1 1 2 ton component within the cooler fall-winter season. Neefus, C. D. , Mathieson, A. C. , Yarish, C. , 3 3 1 1 Microcystin, a hepatotoxin produced by Microcystis, Klein, A. , West, A. , Teasdale, B. & Hehre, E. J. was detected in water and catfish liver samples. Fish 1Department of Plant Biology, University of New exposed to pond water containing this bloom were Hampshire, Durham NH 03824 USA; 2Department of killed within 24 h. Necropsy of fish exposed to pond Ecology and Evolutionary Biology, University of Con- water revealed congested liver and spleen tissues. En- necticut, Stamford, CT 06901 USA; 3Department of vironmental conditions associated with several similar Biochemistry, University of New Hampshire, Durham, bloom events suggest several predictive options to NH 03824 USA forecast conditions supporting toxin formation, particularly temperature. As one part of a multi-institutional project on the biology of Porphyra, we collected extensive population samples of native Porphyra species from Long Island 216 Sound to Nova Scotia. Samples were initially identi- MICROSCOPIC INVESTIGATIONS OF STROM- fied to species based on morphological features using BOMONAS WITH SPECIAL REFERENCE TO taxonomic keys in Bird & McLaughlin (1992). Collec- RELEASE FROM THE LORICA FOLLOWING tions were analyzed using starch gel electrophoresis to CELL DIVISION look for intra-specific variation useful in assessing Zimmermann, S.1, Conforti, V.2 & Triemer, R. E.1 population genetics. Isozyme variation in samples that 1 had been originally identified as Porphyra leucosticta Division of Life Sciences, Rutgers University, Piscat- was far greater than expected. Samples from some 2 away, NJ, 08854 USA; Departmento de Biología, Fac. collections differed by as much as 7 out of 7 loci. Cs. Exactas y Naturales, Ciudad Universitaria, Pab. Other investigators have used starch gel electrophore- II, 1428, Buenos Aires, Argentina sis to reveal cryptic differences in Porphyra that led to the descriptions of new species. In light of our The Euglenophyta include four genera of Euglena-like isozyme results, we began a thorough examination of cells enclosed in a lorica. Two of these genera, Trache- what had been identified as P. leucosticta in the north- lomonas and Strombomonas, are free swimming. These western Atlantic. The study included new collections taxa have been differentiated and classified at the ge- as well as herbarium specimens. We examined mor- neric and species level based primarily on the morphology, habitat, seasonality, reproductive patterns, phology of their lorica. Numerous SEM studies have cell size & shape. We also extracted DNA and se- been conducted, yet few, if any, TEM descriptions ex- quenced 1484bp of the rbcL gene. Based on this evi- ist, especially for Strombomonas. This study describes dence, we feel we can circumscribe at least five dis- both the outer lorica and internal ultrastructure for tinct taxa of Porphyra not previously described from Strombomonas sp. isolated from a fresh water pond in the northwestern Atlantic. Whether these represent New Jersey. Additionally, we describe the release of new species, or previously described taxa from other daughter cells from the lorica following cell division. geographic regions, we are not yet certain. We Two cells were observed within a single Strombomonas present here in detail, descriptions of each species lorica following cytokinesis. When exposed to the along with summarized results of isozyme and DNA light of the microscope, one or both of the cells analyses.