Oral Abstracts

Phylogeny of Syllidae (Phyllodocida, Annelida) based on morphogical data

M. Teresa Aguado* & Guillermo San Martin

Laboratorio de Biologia Marina, Faculte de Ciencias, Universidad Autonoma de Madrid, Canto Blanco, Spain

The phylogeny of Syllidae is assessed in a parsimony analysis of morphological characters. All the valid genera of the four classical subfamilies Eusyllinae, Exogoninae, Syllinae and Autolytinae, as well as several outgroup taxa from other families of Phyllodocida are included. Character informa- tion is based on examination of available types, additional non-types and newly collected material. The monophyly of the four subfamilies as well as the whole Syllidae is discussed. The evolution of the reproductive modes and the different systems of parental care are also considered. Results are compared with those from previous studies and with the most recently published phylogenetic analy- sis of Syllidae based on molecular data from nuclear 18S rDNA and mitochondrial 16S rDNA and cytochrome c oxydase subunit I. Our study also aims to investigate the evolution of some morpho- logical characters traditionally used for the diagnosis of the classical subfamilies and their genera.

Presenter (*) 22 Oral Abstracts

Polychaete diversity on the Northeast Greenland Shelf: effects of water column processes and grain size

William G. Ambrose, Jr.*, Paul E. Renaud & Kirsti A. Sandoy

Department of Biology, Bates College, Lewiston, Maine 04240

Arctic shelves are areas of complex bathymetry and hydrography, offering opportunities to examine patterns of benthic community structure along environmental gradients and potentially determine biotic and abiotic controls on diversity. The Northeast Water Polynya is a recurrent annual feature of variable size on the northeast Greenland shelf. The area is characterized by complex bathymetry: shallow banks (water depth <40–150 m), surrounded by troughs (water depths of 250 to > 500 m). The distribution and abundance of polychaetes and other benthic taxa are primarily related to parameters characterizing organic input to the benthos (water column and benthic pigments). Over 150 polychaete species were identified from replicate cores (0.005 m?) from 28 stations with no indication that the sampling effort was sufficient to collect all the species present. The southern trough had significantly fewer polychaete species per sample (14.7) compared to stations from the northern trough (23.4) or central bank (25.7). The Shannon diversity index and rarefaction curves confirmed the lower diversity in the southern trough compared to the bank and northern trough. The southern trough has greater ice cover than the central bank and northern trough which open earlier in the season, so it is tempting to explain the lower polychaete diversity in the south compared to the north by differences in water column productivity between these areas. Both polychaete species richness and the Shannon diversity index are negatively correlated with grain size, however, and stations in the southern trough have a finer sediment and greater depth than other areas sampled.

Presenter (*) 23 Oral Abstracts

The biological geography of the European Seas: results from the macrofaunal inventory of the soft-substrate communities

Christos Arvanitidis1*, P. Somerfield, H. Rumohr, S. Faulwetter, V. Valavanis, K.Vasileiadou, G. Chatzigeorgiou, E. Vanden Berghe, J. Vanaverbeke, C. Labrune, A. Gremare, M. Zettler, M. Kedra, M. Çodarska-Kowalczuk, D. Fleischer, M. Büntzow & A. Rose

1 HCMR—IMBG, P.O. Box 2214, Heraklion, Crete 71003, Greece

This work has been accomplished in the context of the MarBEF (Marine Biodiversity and Ecosystem Functioning) EU Network of Excellence. The hypothesis tested is whether the zoogeo- graphical regions defined across European seas exist or not. The systems considered were those proposed by OSPAR, ICES, IHO, LMEs, Longhurst and Fredj. Data on soft-bottom communities have been stored in the largest data base of this kind ever developed in the EU. The faunal groups used for the hypothesis testing were: macrobenthos, polychaetes, molluscs, crustaceans, echino- derms and sipunculans. Three criteria were proposed in order to test the perfomance of the above taxa through the application of a variety of uni- and multivariate methods: (1) interpretability, which refers to the biogeographic patterns produced by each group for each system; (2) differenciation, which provides a measure of the uniqueness of the pattern; (3) randomness, which defines the inventories of the various sectors as random samples of the total inventory of each of the systems considered. Results show that only polychaetes meet all three criteria and, accordingly, the only valid marine biogeographic system is the one proposed by Longhurst. The application of recently developed third-stage MDS shows that polychaetes produce a unique pattern when all systems are considered and also that they produce the pattern with highest similarity to the one produced by the macrobenthos, within Longhurst’s system. Average island distance from the nearest coast, number of islands and the island surface area were the geographic variables best correlated with the pattern produced by polychaetes.

Presenter (*) 24 Oral Abstracts

Comments on the validity of three common Harmothoe species (Polychaeta: Polynoidae) in the NE Atlantic

Ruth Barnich* & Dieter Fiege

Sektion Marine Evertebraten II, Forschungsinstitut und Naturmuseum Senckenberg, Senckenberganlage 25, D-60325 Frankfurt, Germany

The scaleworms Harmothoe imbricata (Linnaeus, 1767), H. extenuata (Grube, 1840), and H. impar (Johnston, 1839) are the most abundant and regularly identified Harmothoe species from shallow waters in the NE Atlantic. Unfortunately their type specimens are lost and the original descriptions and figures are insufficient for differentiation from other Harmothoe species occurring in the same habitat. Thus, these species are indeterminable and their names should not be used in the future. Identification keys covering these species are based on redescriptions by different authors published after the respective original description. They represent the opinion of these authors about the dif- ferentiating characters, but it is not possible to prove whether this really meets the intention of the original authors. Our review of the literature revealed that Harmothoe cirrata (Müller, 1776) (origi- nally described as Aphrodita cirrata) is the oldest sufficiently described species covering specimens hitherto identified as H. “imbricata”. As to H. “extenuata” specimens, they are perfectly covered by H. propinqua (Malmgren, 1867) (originally as Lagisca). In the case of H. “impar” specimens, H. reticulata (Claparède, 1870) (originally as Polynoe) is the oldest sufficiently described and fig- ured species. In the NE Atlantic alone about 30 valid Harmothoe species occur, with about 50% of them having been described already in the 19th century. Thus, our results will not only influence forthcoming taxonomic and ecological research on the group in the region, but will be most impor- tant for the revision of the whole genus.

Presenter (*) 25 Oral Abstracts

Cosmopolitan deep-sea polychaete species

James A. Blake1* & Markus Böggemann2

1 ENSR Marine & Coastal Center, Woods Hole, MA 02543 USA 2 University of Osnabrück, Osnabrück 49069, Germany

As part of recent collections of benthic invertebrates from continental slope and abyssal depths from the North and South Atlantic, eastern Pacific, Antarctica, and the central Pacific gyre, some poly- chaete species with apparent “cosmopolitan” distributions were identified. The dorvilleid, Exallous cropion Jumars, from the San Diego Trough off California has been identified from off North Carolina. Ten additional dorvilleid species in five genera have been confirmed as occurring in deep- water surveys off both the U.S. Atlantic and Pacific coasts. Glycera capitata Örsted (Glyceridae), Bathyglycinde profunda (Hartman & Fauchald), B. sibogana (Augener & Pettibone), and Progoniada regularis Hartman (Goniadidae) have been reported in recent deep-sea surveys in the Atlantic and Pacific. Several widely distributed species of Ophelina (Opheliidae) are known as are several species of Aricidea, Cirrophorus, and Levinsenia (Paraonidae). For example, A. simplex (Day), from off South Africa, has been commonly encountered off both the east and west coasts of North America. Mystides caeca Langerhans and M. rarica (Uschakov) (Phyllodocidae) are widely distributed in the Atlantic and Pacific. Among spionids, Aurospio dibranchiata Maciolek, from North and South Atlantic basins, also occurs off California. Prionospio delta Hartman, from off NE South America is a dominant species on the lower continental slope off California. The small syllid Anguillosyllis (=Braniella) palpata (Hartman), from Antarctica has been found in slope sediments off the east and west coasts of North America. Another small syllid Parexogone wolfi San Martín is widely distributed in Atlantic abyssal basins. The question of how small infaunal polychaetes can occur over vast geographic areas is a fascinating question. Large areas of the deep sea floor have few geographic barriers to block species migrations. In addition, very cold Antarctic bottom water (0.5–1.5°C) flows northward from the Weddell Sea at abyssal depths into Atlantic and Pacific basins and influences water depths greater than 3000 m in both oceans. The abyssal habitat there- fore has a constant environment and with few barriers to migration and given sufficient time benthic invertebrates should be capable of broad distributions in continental rise and abyssal depths that link the Antarctic, Atlantic, and eastern Pacific basins. [Supported by the National Science Foundation under Grant No. DEB-0118693 (PEET) to James A. Blake, University of Massachusetts, Boston]

Presenter (*) 26 Oral Abstracts

Current status of invasion and distribution of Marenzelleria (Polychaeta: Spionidae) species in the Baltic Sea

Miriam Blank*, Ari O. Laine, Kay Ruttloff, Kerstin Schwandt, Karl Jürss & Ralf Bastrop

University of Rostock, Institute for Biosciences, Albert-Einstein-Strasse 3, 18059 Rostock, Germany

Since 1985, Marenzelleria neglecta (formerly M. cf. viridis, M. type II) is known from the Baltic Sea where it is an important faunistic element of the macrozoobenthic community. Recently, the successful invasion of two other Marenzelleria species, M. viridis and M. arctia, could be detected by using molecular markers. We will summarize investigations on their invasion and present distri- bution, and give a future perspective on the expected distribution of the species in the Baltic Sea. Furthermore, we will introduce a newly developed PCR/RFLP protocol for discrimination between the three species. Studies of Marenzelleria species are often hampered by identification uncertain- ties when using morphological characters only. The protocol is based on PCR amplification of two mitochondrial DNA gene segments (16S, COI) followed by digestion with restriction enzymes and is recommended for large-scale analyses.

Presenter (*) 27 Oral Abstracts

Molecular data support Myzostomida as part of the annelid radiation

Christoph Bleidorn1*, I. Eeckhaut, L. Podsiadlowski, N. Schult, Damhnait. McHugh, Kenneth. M. Halanych, M. C. Milinkovitch & R. Tiedemann

1 University of Potsdam, Institute for Biochemistry and Biology, Unit of Evolutionary Biology/ Systematic Zoology, Karl-Liebknecht-Str. 24-25, Haus 26, D-14476 Potsdam-Golm, Germany

Myzostomida are marine worms that show an enigmatic lophotrochozoan body plan. Their phyloge- netic origins were obscured due to disagreement about which morphological features are evolution- arily conserved, but now most morphological evidence points to annelid origins. In contrast, recent phylogenetic analyses using different molecular markers produced variable results regarding the position of myzostomids, but all suggested these worms are not derived annelids. Here, we show that the molecular data are in agreement with the morphological evidence that myzostomids are part of the annelid radiation. This result is robustly supported by mitochondrial (gene order and sequence data) and nuclear data, as well as by recent ultrastructural investigations. Using Bayes fac- tor comparison, alternative hypotheses are shown to lack support. Thus, myzostomids probably evolved from a segmented ancestor and gained a derived anatomy during their long evolutionary history of echinoderm symbionts.

[After acceptance for an oral presentation, the organizing committee determined that this paper has already been published: Molecular Biology and Evolution, doi:10.1093/molbev/msm086, April 2007.]

Presenter (*) 28 Oral Abstracts

Morphological and molecular development of the gut in the polychaete Capitella sp. I

Michael J. Boyle* & Elaine C. Seaver

University of Hawaii at Manoa, 1176 Alewa Drive, Honolulu, HI 96817, USA

The alimentary canal of Capitella sp. I is subdivided into distinct regions along its length, including a cuticle-lined buccal cavity, pharynx, esophagus, highly coiled midgut, and hindgut. In Capitella sp. I we have made the surprising observation of the presence of a dorsal pharynx, a type previously known only to occur in oligochaetes and one terrestrial polychaete species. Our evidence includes a thickened epithelium along the pharynx roof, a broad, dorsal ciliated pad surrounded by a cuticular fold, dorsally positioned pharyngeal gland-like structures, and dorsal proboscis retractor muscles. The presence of a dorsal pharynx in Capitella sp. I may have new and important phylogenetic impli- cations for polychaete taxonomy. We also describe the development of the foregut. To begin to investigate the molecular development of the Capitella sp. I gut, we report the characterization and expression of Fox and Gata family members, transcription factors that have conserved functions in patterning the gut across bilaterian phyla. Consistent with a putative role in gut patterning and mor- phogenesis, whole-mount in situ hybridization shows expression from both gene families associated with the developing gut of Capitella sp. I. Not only is each gene expressed in a subregion of the ali- mentary canal, there are boundaries of expression for several of these genes along the gut that corre- late with putative boundaries between ectoderm and endoderm. Collectively, the foxA and gata genes show patterns of expression that together span almost the entire length of the alimentary canal.

Presenter (*) 29 Oral Abstracts

Comparative neurogenesis of brooded and free-swimming polychaete larvae

Nora Brinkmann* & Andreas Wanninger

University of Copenhagen, Institute of Biology, Department of Cell Biology and Comparative Zoology, Universitetsparken 15, DK-2100 Copenhagen Ø, Denmark

In order to assess the ground pattern of the larval neuroanatomy of polychaete annelids, we com- pared neurogenesis in larvae of Sabellaria alveolata (Sabellaridae) and Spirorbis sp. (Sabellidae). Both species exhibit a planktonic larval phase. In the brooding species Spirorbis this phase is rather short, with the lecithotrophic larvae settling a few hours after hatching and undergoing subsequent metamorphosis, whereas in Sabellaria the planktotrophic trochophore larvae remain in the water col- umn for several weeks. It has been shown that variation in life history strategies may be directly linked to differences in morphology and timing during the developmental process. Therefore, we traced the neuronal development using fluorescence-coupled antibodies directed against the neuro- transmitters serotonin and FMR Famide. The staining was analyzed with confocal laser scanning microscopy and reconstructed using 3D visualization software. We found that in both species (1) neuronal differentiation of the first three commissures associated with the larval segments follows a strictly anterior to posterior pattern and (2) the two ventral nerve cords consist of a varying number of immuno-reactive axons. The main difference in neurogenesis appears to be the timing as to when adult features develop. In embryos of Spirorbis the anlagen of the adult cerebral ganglion and the ventral nerve cords are formed prior to the typical larval features such as the prototroch nerve ring, while the planktotrophic larvae of Sabellaria exhibit the expected chronology of neurogenesis, i.e., formation of the larval neural body plan, followed by the adult cerebral and ventral nervous system. Interestingly, the larvae of Sabellaria show a larval apical nerve ring instead of an apical organ, which consists of a neuropile and immunoreactive cell bodies, a feature found in most other Spiralia.

Presenter (*) 30 Oral Abstracts

Phylogeny of the Diopatra complex (Polychaeta, Onuphidae) based on morphological data

Nataliya Budaeva1* & Kristian Fauchald2

1 P.P. Shirshov Institute of Oceanology Russian Academy of Sciences, Nakhimovsky pr. 36, Moscow 117997, Russia 2 Department of Invertebrate Zoology, NMNH, MRC 0163, Smithsonian Institution, P.O. Box 37012, Washington, DC 20013-7012, USA

The Diopatra-complex including the genera Diopatra Audoin & Milne-Edwards, 1833, Paradiopatra Ehlers, 1887 and Epidiopatra Augener, 1918 was established by Paxton (1986) based on presence of such characters as branchiae limited to anterior region of the body, lateral projections on ceratophores, and long pointed hoods in anterior falcigers. None of the characters are present in all species of any of the genera. We tested the hypothesis of monophyly for this group. The study included 27 species of Paradiopatra, 12 species of Diopatra and 4 species of Epidiopatra; 11 species from 9 other onuphid genera were included in the analysis to test of the monophyly of the Diopatra complex per se and of its three genera. Eunice valens (Chamberlin, 1919) was chosen as outgroup taxon. Two different methods of character coding: composite and reductive (Strong & Lipscomb, 2005) were applied. Respectively, 49 and 57 multistate unordered and equally weighted characters were applied. The parsimony analysis demonstrated the monophyly of the Diopatra complex, but with the addition of the genus Notonuphis Kucheruk, 1978. Within the complex the genera Diopatra and Epidiopatra form a monophyletic group indicated by the spirally arranged branchial filaments. Epidiopatra is paraphyletic, possibly a pedomorphic taxon, and should be synonymized with Diopatra. Paradiopatra and Notonuphis appear to be paraphyletic taxa. One species, Paradiopatra willemoesii (Mcintosh, 1885) demonstrated several plesiomorphic characters and always joined the outgroup taxa; it probably should be considered as the type of a new monotypic genus.

Presenter (*) 31 Oral Abstracts

Phylogeny of Sabellidae (Polychaeta), inferred from morphology and multiple genes.

Maria Capa1*, P.A. Hutchings2 & N. Bott1

1 Guatemala 8 6A, Madrid 28016, Spain 2 Marine Invertebrates, Australian Museum, 6 College Street, Sydney NSW 2010, Australia

Phylogenetic analyses using parsimony were performed based on both morphological and molecular data to test the relationship among families previously considered among Sabellida and the generic relationships within Sabellidae. A total of 33 terminal taxa of Sabellidae together with members of Serpulidae, Sabellaridae, Siboglinidae, Oweniidae, Terebellidae and Cirratulidae were included in the analyses. Morphological data was obtained from literature and material examined, adding new taxa, characters and states to previous studies. Molecular data were based on partial 18s rDNA, 28s rDNA, 16s rDNA and COI sequences with most sequences newly sequenced and the rest were obtained form Genbank. We will discuss our findings and compare them with the currently accepted classification.

Presenter (*) 32 Oral Abstracts

Ship–Worms: Global Humans and Global Polychaetes

James T. Carlton

Maritime Studies Program, Williams College-Mystic Seaport, P.O. Box 6000, Mystic, CT 06355, USA

Despite the commencement of the global dispersal of polychaete worms by ships sailing the world’s oceans in the 1500s, few invasions of non-native polychaetes are recognized prior to the 1900s, or 400 years after the human-mediated global bioflow of ship-associated marine life began to homoge- nize the world’s oceans. Many species are reported as “cosmopolitan,” a situation that can result from three phenomena: a cosmotaxon may be, 1) two or more morphospecies or genospecies, 2) a naturally widely-occurring species, which has failed to speciate despite apparent long isolation and thus lack of gene flow, or 3) one species carried around the world by ships and other human-medi- ated means. We explore the ramifications of the third possibility, in terms of what the world of worms may have been like, only half-a-millennium ago.

Presenter (*) 33 Oral Abstracts

Evolution of Ophryotrocha in marine chemosynthetic environments

Thomas G Dahlgren1*, Helena Wiklund1, Craig R Smith2 & Adrian Glover3

1 Göteborg University, Department of Zoology, Box 463, 40530 Göteborg, Sweden 2 University of Hawaii at Manoa, 1000 Pope Rd., Marine Sciences Building, Honolulu, HI 96822, USA 3 Zoology Department, The Natural History Museum, Cromwell Rd, London SW7 5BD, UK

Annelids of the genus Ophryotrocha are among the most common organisms in deep-sea reducing habitats such as hydrothermal vents, cold seeps and large organic remains. While littoral representa- tives of the group has been used as a model for a variety of biological research, including eco-toxi- cology, behavior, ecology, sex determination, ontogeny and phylogeny, virtually no work addresses sub-littoral species. In this study we present phylogenetic, behavioral and life history data from four new species of Ophryotrocha collected at an experimentally implanted whale carcass at 125 m depth in the North Atlantic. The new data suggest that 1) the new species are grazers on sulphur oxidizing bacterial mat, 2) they are gonochoristic and 3) they are closely related to littoral Ophryotrocha.

Presenter (*) 34 Oral Abstracts

Analyses of Biocements from Pectinaria gouldii and Phragmatopoma lapidosa

Maria Dean* & Thomas Tauer

Department of Chemistry, Coe College, 1220 First Ave NE, Cedar Rapids, IA 52402, USA

Pectinaria gouldii and Phragmatopoma lapidosa are marine annelids that reside in protective struc- tures built from sand granules bound together using proteinaceous cement secreted from specialized glands. P. gouldii constructs an ice cream cone structure. The smaller, gregarious P. lapidosa forms a large, reef-like mound. The surface structures and composition of hydrated and dehydrated cement were analyzed using: Atomic Force Microscopy (AFM), Raman Spectroscopy, Scanning Electron Microscopy (SEM), and Electron Dispersive Spectroscopy (EDS). The protein composition of the cement was elucidated using amino acid analysis. Calcium binding proteins were identified using Stains-all after polyacrylamide gel electrophoresis. We also report the analysis of extracted bioce- ment proteins using Surface Enhanced Raman Spectroscopy (SERS). Atomic force analyses indicate that [in their native states] the surface roughness of P. gouldii cement is more pronounced including additional surface features than P. lapidosa. The surface of P. gouldii resembled “cottage cheese.” SEM reveals fibrous structures that become obvious in the dehydrated state and “popped bubble” features that indicate a foam-like material in its native state for both cements. EDS confirms the presence of calcium, magnesium, and phosphorous in both cements, with varying amounts of these three elements at different locations on the same sample. Raman studies, SERS, and total amino acid analysis indicate similarities in amino acid composition of the two cements. High serine con- tent and staining with Stains-all indicate the presence of phosphorylated proteins that may be involved in calcium binding in forming the cements. Comparison of our data with that from litera- ture will be made.

Presenter (*) 35 Oral Abstracts

Polychaete fauna in the vicinity of bleufin tuna sea-cages in Ensenada, Baja California, Mexico.

Victoria Díaz-Castañeda

CICESE, Km. 107 Carretera Tijuana-Ensenada, 22800 Ensenada, B.C., México.

Sea-cage farming results in a constant rain of organic waste onto the surrounding benthos. There is growing concern over the effects of sea-cages on the local environment: sediment chemistry and benthic communities. Samples were taken with a Van veen grab (0.1 m2) in 2003 and 2004. Organisms belonging to 7 Phyla were collected: Polychaeta, Mollusca, Crustacea, Echinodermata, Cnidaria, Sipuncula and Bryozoa. Polychaetes accounted for 61% of the benthic macrofauna. 5,720 polychaetes were collected in 18 stations, representing 34 families. Best represented families in 2003 and 2004 were Paraonidae, Cirratulidae, Spionidae, Capitellidae and Syllidae. Redox poten- tial was measured in the field, in 2003 Eh values ranged between -115 and -200 mV, while in 2004 they oscillated between -110 and -302. In the northwest section of the bay we found in 2004 the highest value of organic C (2.53%), west of the tuna pens. Recent data (2006) show values of total C up to 5.3% south and west of tuna pens. The most abundant species were Aphelochaeta multifilis, Mediomastus ambiseta, Prionospio steenstrupi Spiophanes bombyx, Apoprionospio pygnaea, Paraonella sp, Monticellina sp, Aricidea (Allia) ramosa, Spiophanes bombyx and Levinsenia gra- cilis. The dominant trophic group was deposit-feeders.

The diversity (Shannon index) at family level ranged between 1.80 to 2.35 in 2003 and between 1.90 and 2.63 in 2004. The stress-predictability method (Alcolado, 1982) characterized 61% of Bahía Salsipuedes as slightly disturbed. Non-metric multidimensional scaling (MDS) separated sta- tions depending of the distance to the tuna pens.

Presenter (*) 36 Oral Abstracts

Challenging the paradigms of proboscis eversion in genus Nephtys

R.R. John Dinley1*, L.E.H. Hawkins, Gordon Paterson2 & A. Ball

1 National Oceanography Centre, Southampton University, 21 Ashwood Drive, Broadstone, Dorset, BH18 8LN, UK 2 Department of Zoology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK

It is widely accepted that an increase in coelomic pressure that is the primary mover in the eversion of the proboscis in most polychaetes with a “simple” axial pharynx. However, our observations of Nephtys caeca and N. hombergi have lead us to question the accepted view and postulate that mus- cular function may be the primary instigator of pharyngeal extrusion and that increases in coelomic pressure are consequent to these changes. The unique shape, structure, and muscular attachments of the Nephtys pharynx together with a similarly unique muscle structure containing large quantities of calcium phosphate granules in the sarcoplasmic cores of the striated muscles, all contribute to the evidence for this hypothesis. There is also new evidence that a pair of muscles extending inferiorly and posteriorly from the Nephtys pharynx have several roles and not just those of “retensor” func- tion. They appear, not only play a significant role in pharyngeal extrusion and stability, but also a major protective role for both the intestine specifically and the whole anterior 45 segments of worm generally generally. In view of the newly identified extended function and importance of these mus- cles which has come about from the micro-dissection of over 150 specimens of Nephtys caeca and N. hombergi we have provisionally named these muscles as the ventral coelomic muscles. (VCM).

Presenter (*) 37 Oral Abstracts

Density and depth gradient patterns in deep-sea polychaetes: Implications for species diversi- ty estimates

Stacy A. Doner* & James A. Blake

ENSR Marine & Coastal Center, 89 Water Street, Woods Hole, MA 02543 USA.

Polychaetes of the Cirratulidae, Paraonidae, and Spionidae are among the most speciose families in continental slope and rise sediments off the coast of California. The benthic infauna in slope sedi- ments off California is shown to be zoned by depth with well-defined assemblages in upper, middle, and lower slope depths. Lower slope depths (2200–3200 m) have been extensively monitored in recent years; recently additional samples have been obtained from depths of 3600-4100 m. The objective of this study is to analyze the bathymetric distribution of selected species of Cirratulidae, Paraonidae, and Spionidae in order to identify zonation gradients of individual species. These results are used to test the source-sink hypothesis. We hypothesize that the continental margin and abyss of the eastern Pacific do not constitute a source-sink system for polychaetes and that individ- ual species will have a specific depth range within which reproduction and major recruitment take place, regardless of whether one considers slope, rise, or abyssal depths. We believe there is a true abyssal polychaete fauna across the Pacific Ocean. Species abundance is plotted along depth gradi- ents to identify optimal depths of occupancy for each species examined as well as a range symme- try/asymmetry. Evidence of sexual maturity and presence of gametes together with presence of juveniles along depth gradients for each species will be discussed. [This study was supported by the National Science Foundation under Grant No. DEB-0118693 (PEET) to James A. Blake, University of Massachusetts, Boston.]

Presenter (*) 38 Oral Abstracts

Burrowing by crack propagation: why worms are wedges

Kelly M. Dorgan* & Peter A. Jumars

Darling Marine Center, University of Maine, 193 Clarks Cove Road, Walpole, ME 04573, USA

Marine muds are elastic solids through which animals move by propagating a crack-shaped burrow. Dilations previously considered anchors serve to exert radial compressive stress that, through elastic behavior of the medium, focuses axial tensile stresses strongly at the tip of the burrow. This focused stress breaks adhesive bonds, propagating a crack for the animal to follow. This mechanism of bur- rowing by fracture is consistent with descriptions of burrowing across phyla and helps explain long- puzzling anatomies and behaviors of burrowing animals. For example, lateral head movement while burrowing, previously described as a mechanism to decrease the viscosity of mud to ease penetration, actually extends the crack-shaped burrow laterally, reducing the internal pressure need- ed to maintain the worm‚ body shape in mud, which is an elastic solid, not a fluid. Muscular anteri- or regions (e.g., cirratulids) and rigid wedge-shaped anteriors (e.g., the trichobranchid, Artacamella hancocki) have a similar function‚and exert a dorso-ventral force to extend the crack while burrow- ing. Crack propagation also gives insight into the general body plan of many polychaetes (e.g., Scalibregma) that tends toward bilateral symmetry in the anterior where crack propagation and entry is the major issue and the posterior, where resisting elastic rebound of the sediment is a priori- ty and radial symmetry dominates. Understanding of this mechanism raises questions about the reputed high energetic cost of burrowing; feeding guild classifications‚specifically surface deposit feeders‚and identifies some potential artifacts in benthic studies of chemistry and bioturbation.

Presenter (*) 39 Oral Abstracts

Highly diverse assemblages of dorvilleid polychaetes in two methane seep areas of the north- east Pacific

Brigitte Ebbe1*, Kenneth Halanych2 & Guillermo Mendoza3

1 Forschungsinstitut Senckenberg, DZMB, c/o Forschungsmuseum König, Adenauerallee 160, D- 53113 Bonn, Germany 2 101 Life Sciences Building, Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA 3 Scripps Institution of Oceanography, 9500 Gilman Drive, La Jolla, CA 92093, USA

During a cruise to two cold seep areas off Oregon and California in October 2006, numerous speci- mens of dorvilleid polychaetes were collected with the help of the submersible Alvin. While super- ficially similar to dorvilleids from the slope and rise of both the Pacific and Atlantic Oceans and also from hydrothermal vents and whale falls, they appear to represent a unique assemblage of species. Deep-sea dorvilleids are sometimes considered relicts of a very ancient fauna, but the sur- prising diversity in both “normal” and chemosynthetic environments suggests that radiation events may have taken place and that these dorvilleids are highly derived forms. Affinities with assem- blages from other chemosynthetic environments and locations on the continental slope and rise will be discussed, based on morphological and molecular evidence

Presenter (*) 40 Oral Abstracts

Subfamilies of Polynoidae (Annelida: Aciculata)

Kristian Fauchald1* & Robin Wilson2

1 Department of Invertebrate Zoology, NMNH, MRC 0163, Smithsonian Institution, P.O. Box 37012, Washington, DC 20013-7012, USA 2 Museum Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia

Currently 21 subfamilies have been proposed for the polynoid scale worms, varying in scope from a single species (e.g., Gesiellinae, Uncopolynoinae) to several hundred species (e.g., Polynoinae). Most subfamilies have been defined on a single obvious feature or on a combination of a few obvi- ous features. A cladistic analysis of the type species for all published genera shows that the situa- tion is rather more complex than the current system allows. The analysis was based on 173 termi- nal taxa, including five outgroup taxa representing the other scale worm families, scored for a total of 200 mostly multistate characters. The characters includes the traditionally recognized features such as numbers of pairs of elytrae, kinds of chaetae present and the shape and position of the ante- rior appendages. We added consideration of additional features, such as the facial tubercle, jaws, pharyngeal papillae and especially the pygidium and modifications of posterior chaetigers. To avoid problems with misidentifications, this primary characterization is based mainly on examina- tion of type specimens and review of original descriptions; this precludes consideration of age (size) related variability as well as individual variation which may even further complicate interpretation of the phylogeny. However, the analysis demonstrates that especially the smaller subfamilies can be easily submerged without loss of information.

Presenter (*) 41 Oral Abstracts

Species of Harmothoe (Polychaeta: Polynoidae) associated with Lophelia reefs in the NE Atlantic and in the Mediterranean

Dieter Fiege* & Ruth Barnich

Sektion Marine Evertebraten II, Forschungsinstitut und Naturmuseum Senckenberg, Senckenberganlage 25, D-60325 Frankfurt, Germany

Deep-water reefs formed by cold-water corals, e.g. Lophelia pertusa, occur in all oceans. They are widely distributed over the NE Atlantic and are also found in the Mediterranean. Although the ecol- ogy of these reefs is still poorly understood they are known to support a diverse invertebrate fauna including various polychaete species and potentially act as nursery areas, e.g. for commercial fish species. Among the scale worms of the family Polynoidae to be found on these reefs are Harmothoe oculinarum (Storm, 1879) and Harmothoe vesiculosa Ditlevsen, 1917, both representing poorly known species. Until recent collecting in deep water reefs off N Norway, in the Bay of Biscay and off Cape Santa Maria di Leuca (Italy) no confirmed records existed of these two species besides their original descriptions. The find off Cape Santa Maria di Leuca extends the distributional range of H. vesiculosa into the Mediterranean. Based on our material both species are redefined and a lec- totype for H. vesiculosa is designated.

Presenter (*) 42 Oral Abstracts

Cell lineage and the origin of the body regions in nereidid development revisited

Albrecht Fischer* & C. Ackermann

Zoological Institute, University of Mainz, Stuettgerhofweg 4c, D-50858 Koeln, Germany

The description of early development of Nereis by E. B. Wilson (1892) has become a very influen- tial case study of embryogenesis in a spiralian. However, these results have not been corroborated nor refined ever since because the technical approach could neither be improved in nereidids nor in any other polychaete. In Platynereis dumerilii, we succeeded in labeling single cleavage cells (blas- tomeres) by softening the egg envelope and injecting fluorescent dye. We have analyzed their histo- genetic fates as expressed in the three-segmented early worm. Its body is subdivided into a stereo- typic pattern of blastomere-specific clones that mostly conform in extent and tissue quality to Wilson’s analysis. It is shown how asymmetry in the cleavage cell pattern in the early embryo is transformed into bilateral symmetry in the early worm. The process of symmetrization takes differ- ent courses in the head and the trunk, respectively, and is in part determined by the spiralian mode of cleavage. Embryological evidence is lacking for the existence of a “peristomium” region sensu Hatschek (a cylindrical region intercalated between head and segmented trunk, bearing the mouth opening and a priori lacking extremities). Instead, the nereidid “peristomium” including the peristo- mial tentacles is generated by offspring of the blastomeres 2d and 4d, the founder cells of the whole trunk ectoderm and mesoderm, indicating its original nature as part of the segmented trunk.

Presenter (*) 43 Oral Abstracts

The Big Chill: spatial variability of population structure and reproductive features of some polychaetes in the soft bottoms of Terra Nova Bay (Ross Sea, Antartica).

Mariamichea Cigliano, Anita Apicella & Maria Cristina Gambi*

Stazione Zoologica Anton Dohrn, Laboratorio di Ecologia del Benthos, Pta S. Pietro, 1 80077 Ischia (Naples), Italy

The polychaetes are an important component of Antarctic benthos, however despite their high diver- sity and abundance, life cycle and autoecology of most species are still quite scarce. We studied the population structure and reproductive status of nine abundant species of polychaetes and their spa- tial variability in selected depths and sites of the soft bottoms off Terra Nova Bay (Ross Sea, Antarctica). In each selected sites, at Faraglione, Adelie Cove, two fixed stations were sampled: shallow at about 50–60 m; and deep at about 120–150 m. In each station quantitative samples were take with a Van Veen grab (three replicates) during the austral summers 1989-90, 1993–94, and 2000–01. The more abundant species studied were Tharyx cincinnatus, Axiothella antarctica, Maldane sarsi, Aglaophamus trissophyllus, Leitoscoloplos mawsoni, Perkinsiana milae, Spiophanes tcherniai, Laonice weddellia, and Myriochele wilsoni. Only A. trissophyllus was more abundant in the shallow stations, while the other species were distributed mainly in the deep ones. Mean sizes of L. mawsoni, A. antarctica, M. sarsi, and P. milae, were significantly lower in the deep station of Adelie Cove, and probably related to the presence in this area of “sponge spicule-mat‚” and more heterogeneous sediment. Ovigerous females occurred in various species and their proportion was higher in the shallow station of Faraglione, while only P. milae showed asexual reproduction. The highest variability in space, and among different study periods, was observed for the small-sized species T. cincinnatus, L. mawsoni and P. milae and were likely related to their small size, relatively short life-span and probably rapid response to local environmental features.

Presenter (*) 44 Oral Abstracts

Why whale bones on the seafloor can be both stepping-stones for vent species and sources of remarkable adaptive radiation in polychaetes

Adrian G. Glover1*, Craig R. Smith2, Kirsty M. Kemp,1 & Thomas G. Dahlgren3

1 Zoology Department, the Natural History Museum, Cromwell Rd, London SW7 5BD, UK 2 University of Hawaii at Manoa, 1000 Pope Rd., Marine Sciences Building, Honolulu, HI 96822, USA 3 Göteborg University, Department of Zoology, Box 463, 40530 Göteborg, Sweden

When whales die, they sink to the seafloor and provide an enormous point-source of organic enrich- ment. Recent studies of both naturally-found and experimentally-implanted whale remains have shown how a reducing environment dominated by sulfur-oxidizing bacteria and associated meta- zoans can form at these environments, and remain active for up to 100 years. Our studies of whale- falls in the deep Pacific Ocean and shallow north Atlantic have shown how a remarkable diversity of polychaete fauna may form in these habitats. These include polynoid species which are also known from hydrothermal vents, as well as the whale-fall specialist Osedax, the bone-eating worm. Using a combined morphological and molecular genetic approach, we have been investigating the ability of these organisms to disperse (over both ecological and evolutionary time-scales) between these isolated and apparently ephemeral habitats. Our studies suggest that while whale-falls may offer habitat conditions suitable for some vent or seep species, they have also presented an opportu- nity for an adaptive radiation event in the Osedax clade, akin to that which has occurred in hydrothermal vent vestimentiferans. These data support the hypothesis that whale-falls, in the form of whale bones on the seafloor, are much more abundant throughout the world’s oceans than previ- ously thought.

Presenter (*) 45 Oral Abstracts

Advances in our understanding of annelid phylogeny

Kenneth M. Halanych1*, Yvone Valles,2 Torsten H. Struck3, Nancy Schult4, Christoph Bleidorn5, J. L. Boore6, Damhnait McHugh4

1 Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA 2 Evolutionary Genomics Program, DOE Joint Genome Institute and Lawrence Berkeley National Laboratory Walnut Creek, CA 94598, USA 3 Universität Osnabrück, FB05 Biologie/Chemie, AG Spezielle Zoologie, Barbarastr. 11, 49069 Osnabrück, Germany 4 Colgate University; Department of Biology; 204 Olin Hall; Hamilton, NY 13346; USA 5 University of Potsdam, Institute for Biochemistry and Biology, Unit of Evolutionary Biology/ Systematic Zoology, Karl-Liebknecht-Str. 24-25, Haus 26, D-14476 Potsdam-Golm, Germany 6 Integrative Biology Department, University of California Berkeley, CA 94720, USA

Understanding the evolutionary relationships of annelid worms has long been a challenge to biolo- gists. Over the past decade, the classical understanding of annelid relationships has been replaced by the framework established in Rouse and Fauchald’s (1997) cladistic analyses of morphological characters. In comparison, results from molecular data have provided incremental changes to our understanding of annelid evolution mainly because of limited phylogenetic signal in the primary source of annelid molecular data, the 18S nuclear ribosomal gene. Recently, several multigene datasets have been released that provide further insights. In particular, combined analysis of 18S, 28S, and EF1? data generally support the Aciculata hypothesis, but fail to support other major clades (e.g., Scoelicida, Canalipalpata) observed in morphological cladistic analyses. Additionally, we report on preliminary results from approximately 30 complete or nearly complete mtDNA genomes. By examining gene arrangement, inferred amino acids, or nucleotides mtDNA data can be useful at different phylogenetic levels. Furthermore, taxon sampling for mtDNA genomes is begin- ning to be robust enough to address some issues of deep-level annelid phylogenetics. For example, as with analyses of combined nuclear gene data, chaetopterids fall near the base of the annelid tree. Herein, we briefly review the sources of molecular data and their utility. Recent results of WormNet group will be presented.

Presenter (*) 46 Oral Abstracts

On the phylogenetic position of Orbiniidae

Harald Hausen*, Sabine Hoffmann & Carsten Koch

Institut für Biologie, Systematik und Evolution der Tiere, Freie Universitaet Berlin, Koenigin- Luisen-Strasse 1-3, 14195 Berlin, Germany

Decreasing support for Scolecida encouraged us to investigate chaetal arrangement and nuchal and dorsal organ ultrastructure of Orbiniidae in comparison to other sedentary polychaetes and to reevaluate traditional views on possible affinities between orbiniids and spionids, apistobranchids and paraonids. As a result Orbiniidae differ markedly from Apistobranchidae, but resemble spi- omorph polychaetes in three characters. The neuropodial chaetal patches in Orbiniidae are com- pletely different organized than those of Apistobranchidae. In addition to a high number of regular transverse rows with a dorsal formative site, the orbiniid patches exhibit a second ventrocaudal formative site, which gives rise to a bent ventral row. A similar second formative site is present in Spionidae, Poecilochaetidae and as well in Paraonidae, but not in numerous other sedentary poly- chaete taxa. The nuchal organs of Scoloplos armiger show the very same apical cover by inflated supportive cell microvilli as present in Spionidae, Poecilochaetidae, Trochochaetidae, Paraonidae, Protodrilida and Capitellidae, but which is not known from other sedentary polychaetes. The seg- mental dorsal ciliary fields in Scoloplos armiger most probably represent metameric repetitions of the nuchal organs. The ultrastructrue is nearly identical. The only other polychaete taxon with known metameric correspondences of nuchal organs is Spionidae. The data do not support Scolecida and favor a closer relationship of Orbiniidae and spiomorph polychaetes.

Presenter (*) 47 Oral Abstracts

Polychaete Community Structure in Tampa Bay, Florida USA.

David. J. Karlen*, Thomas L. Dix., Barbara K. Goetting &, Sara E. Markham

Environmental Protection Commission of Hillsborough County, 3629 Queen Palm Drive, Tampa, FL 33619, USA

The Environmental Protection Commission of Hillsborough County has been conducting benthic monitoring in Tampa Bay since 1993. Samples are collected annually during the late summer using a Young-modified Van Veen grab (sampling area =0.04m2). Over the twelve year period 1993–2004 a total of 1,217 samples were processed and over 1,500 benthic macroinvertebrate taxa were identi- fied. Polychaetes accounted for a third of the overall species richness and abundance with approxi- mately 500 species representing 48 polychaete families and 145,555 individuals. Eight families accounted for 54% of the polychaete species, with Syllidae being the most speciose (79 taxa or 16% of polychaete taxa) followed by Spionidae (40 taxa; 8% of polychaete taxa). Four families made up 55% of the polychaete abundance with Spionidae (23%) being the most abundant family followed by Cirratulidae (15%). Bay-wide, Monticellina cf. dorsobranchialis (Cirratulidae) was the most abundant polychaete accounting for 13% of the abundance. Other abundant taxa included three spi- onids: Prionospio (Minuspio) perkinsi, Carazziella hobsonae, Paraprionospio pinnata and a spiror- bid: Janua (Dexiospira) steueri. Physical factors that most strongly influenced the community structure were depth, salinity and sediment composition (% silt +clay). The sediment composition had the strongest correlation of any single factor. There was a general trend in increasing species richness towards the mouth of the bay which corresponded to increasing salinity and decreasing % silt+clay content. Temporal changes in species composition were correlated with variations in salin- ity and overall diversity was generally lower during periods of reduced salinity.

Presenter (*) 48 Oral Abstracts

Phylogenetic relationships of whale-fall, wood-fall and hydrothermal vent polynoids

Kirsty M. Kemp1*, Erica Goetze, Thomas G. Dahlgren2, Craig R. Smith3, Amy Baco-Taylor4 & Adrian G. Glover5

1 Zoology Department, the Natural History Museum, Cromwell Rd, London SW7 5BD, UK 2 Göteborg University, Department of Zoology, Box 463, 40530 Göteborg, Sweden 2 University of Hawaii at Manoa, 1000 Pope Rd., Marine Sciences Building, Honolulu, HI 96822, USA 4 Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA 5 Zoology Department, The Natural History Museum, Cromwell Rd, London SW7 5BD, UK

Polychaete worms are highly abundant at deep-sea chemosynthetic habitats, such as hydrothermal vents, cold seeps and areas of heavy organic input, such as whale-carcasses or wood-falls. Clarification of the biogeography of these polychaetes, specifically the degree of ecological and evolutionary relatedness between species inhabiting these three different types of chemosynthetic habitat, is the key to understanding the dispersal and colonization processes which have enabled annelid worms to so successfully colonize the deep ocean environment. Here a combined molecular and morphological approach has been utilized to examine the relationship between polynoid poly- chaetes occupying whale, wood and hydrothermal vent habitats at both population and species level. Specimens were collected from wood and whale falls in the Santa Cruz and Santa Catalina Basins (Southern California) at depths of 1200-1600m, and from a whale fall site at 120m depth in Kosterfjord, Sweden.

Presenter (*) 49 Oral Abstracts

Chaetal inversion in Sabellida and Sabellariidae–a disputed character reevaluated

Dominik Kieselbach1* & Harald Hausen

Institut für Biologie, Systematik und Evolution der Tiere, Freie Universitaet Berlin, Koenigin- Luisen-Str. 1-3, 14195 Berlin, Germany

The main morphological character claimed to support a sister group relationship between Sabellida and Sabellariidae is the chaetal inversion. However, a sister group relationship is not supported by molecular studies and even a closer relationship is discussed for years. We thus reinvestigated the chaetal arrangement in sabellids and sabellariids by SEM and serial section based 3D resconstruc- tions. As a result both taxa mainly share plesiomorphic characters, but differ in apomorphic aspects. Both, Sabellidae and Sabellariidae bear strict transverse rows with a dorsal formative site in neu- ropods and a ventral one in notopods like common in sedentary polychaetes. Spiralic and c-shaped rows develop from initial transverse rows in S. pavonina resp. B. Bombyx. Sabellidae but not Sabellariidae show an additional dorsocaudal situated formative site in the thoracic notopods, which forms a distinct single row of so called superior chaetae. The characteristic, nearly mirror symmetri- cal dorsoventral changeover of uncini and capillary chaetae from the last thoracic to the first abdominal setiger‚ the chaetal inversion – is abrupt in Sabellidae and accompanied by a changeover of the whole parapodial morphology. The situation in Sabellariidae is different. Since uncini occur only in the abdomen but are lacking in the thorax and parathorax, the chaetal arrangement is not dorsoventrally inverted. Moreover, the neuropodial chaetal composition changes gradually from parathorax to abdomen. It is concluded that the character chaetal inversion as defined in Sabellida is not present in Sabellariidae. It is less parsimonous to assume a common inheritance than a com- pletely independent evolution of the chaetal arrangement in Sabellidae and Sabellariidae.

Presenter (*) 50 Oral Abstracts

How similar are the polychaete faunas of the Ross and Weddell Sea shelves?

Kerstin Kröger1* & Americo Montiel2

1 National Institute of Water & Atmospheric Research, NIWA, 301 Evans Bay Parade, (Private Bag 14-901), Kilbirnie, Wellington 6021, New Zealand 2 Instituto de la Patagonia, Universidad de Magallanes in Punta Arenas, Chile

A comparative study of benthic polychaete assemblages of two of the largest shelf areas of Antarctica, the Ross Sea and the Weddell Sea, was conducted to seek commonalities and differences between the assemblages in order to elucidate distributional patterns and potential faunistic and zoogeographical links. The analysis is based on data collections from the New Zealand‚ BioRoss‚ expedition to the Northwestern Ross Sea shelf in 2004 and from German expeditions to the Southeastern Weddell Sea shelf in 1998 and 2000. In order to extend the geographical scale of the comparative evaluation, additional data were sourced from the literature. Only benthic data from a depth range of 100–1000 m and with station coordinates were accepted for the analysis. Multivariate statistical techniques utilising similarity measures were used in order to describe and compare the polychaete assemblages and relate distribution patterns. Preliminary results based on qualitative data indicate that Ross and Weddell Sea polychaete faunas - despite a certain degree of overlap - are significantly different in their assemblage composition. The Weddell Sea fauna showed a higher species richness with species belonging to 33 families whereas in the Ross Sea only 29 families occurred. Polynoidae and Terebellidae were the most speciose families in both data sets. Results will be discussed in the light of the question whether a circum-Antarctic distribution pattern exists for polychaetes.

Presenter (*) 51 Oral Abstracts

Are feeding larvae always primitive? What serpulid phylogeny can tell us about metazoan life history evolution.

Elena K. Kupriyanova1* & Greg W. Rouse2

1 School of Earth and Environmental Sciences, Darling Building DP 418, University of Adelaide, Adelaide SA 5005, Australia 2 Marine Biology Research Division 0202, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093, USA

Many marine animals have complex life cycles with alternating pelagic planktotrophic larvae and benthic adults. An enduring theory about metazoan evolution states that such a life history with feeding larvae is primitive and larval feeding is lost but not gained. The planktotrophic trochophore larva of serpulid annelids has often been used as a “model” for the ancestral trochophore state for a large clade of animals, Trochozoa. If serpulid feeding larvae, “the classical trochophores”, were shown to be secondary within the group, this would raise doubts about established theories of life history evolution in animals. We established a detailed morphological and molecular phylogeny for Serpulidae and assessed the evolution of larvae in the group. Although best known as external fertil- izers with feeding larvae, serpulids do show a wide variety of reproductive modes and a surprising range of brooding mechanisms, and lecithotrophic larval forms are common. Our results suggest that the feeding larval form is in fact secondary within Serpulidae and seems to have appeared only once in the group. The implications of this are discussed.

Presenter (*) 52 Oral Abstracts

Evidence for cospeciation events in the host-symbiont system involving myzostomids (Myzostomida) and crinoids (Echinodermata).

Deborah Lanterbecq1*, Greg Rouse2 & Igor Eeckhaut1

1 Marine Biology Laboratory, University of Mons-Hainaut, 6, av. du Champ de Mars, Batiment des Sciences de la vie (Pentagone), 7000 Mons, Belgium 2 Marine Biology Research Division 0202, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093, USA

In the course of evolution, many organisms become associated intimately and acquire gradually a morphology, physiology, and/or behaviour adapted to their symbiotic way of life. This evolutionary process, commonly known as coevolution, was mainly investigated for host-parasite and host-mutu- alist systems. The present work aims at investigating the coevolution between myzostomid and their crinoids hosts, an ideal model of coevolution in a host-commensal system. The cophylogeny was analysed by evaluating the phylogenetic congruence between the two taxa: relationships between sixteen myzostomid species (five genera) were investigated and compared with those of their crinoid hosts (sixteen species; twelve genera). Myzostomid and crinoid phylogenies were estimated (using 18S rDNA, 16S rDNA, and COI sequences for the former and 18S rDNA and COI for the latter) and the host-symbiont cophylogeny was investigated by a Jungle analysis (Charleston and Page, 2002) and a Parafit statistical test (Legendre et al., 2002). Parafit test indicated the presence of a significant cophylogenetic structure between crinoid and myzostomid trees, but only a few sig- nificant cospeciated crinoid-myzostomid associations. Jungle analyses gave several evolutionary scenarios, always suggesting a minimum of 8 cospeciation events. The number of other evolution- ary events was variable and comprised between 1 to 3 symbiont duplications, 4 to 6 host switches and 7 to 16 symbiont sorting events, according to the parameters settled before the analysis. All evolutionary scenarios contained significantly more cospeciation events than it would have been expected due to chance alone.

Presenter (*) 53 Oral Abstracts

Making sense of worm senses: an integrated approach to studying chemoreception in spionid polychaetes

Sara M. Lindsay*, D.L. Forest, T. Riordan & M. Tsie

School of Marine Sciences, 5751 Murray Hall, University of Maine, Orono, ME 04469, USA

Nervous system and sensory structure morphologies provide useful information for reconstructing phylogenetic relationships among the Polychaeta, Annelida and Arthropoda. With the more common use of indirect immuno-cytochemistry and laser scanning confocal microscopy methods, the detailed information available from morphological studies has increased. Despite this wealth of information, developing an integrated understanding of the ecology, physiology, morphology, and molecular mechanisms of sensory systems in the polychaetes remains a challenge. In this presenta- tion I will summarize the results of our integrated study of chemoreception in spionid polychaetes. Because sediment bioturbation rates are influenced by infaunal deposit feeding, we investigated the process of chemoreception and how it coordinates deposit feeding in spionid polychaete worms. We described the ultrastructure and innervation of putative sensory structures on spionid feeding palps using electron and confocal microscopy. To link structures with function, we described the effect of several particle-bound chemical cues on feeding behavior of the spionid Dipolydora quadrilobata, and showed that the same cues activated sensory cells on the feeding palps in activity-dependent cell-labeling studies. Our recent molecular biological results suggest that the chemoreception signal transduction pathway in D. quadrilobata involves G-protein coupled receptors, with g-protein alpha subunit immuno-reactivity localized in the nuchal organs and sensory cilia on the feeding palps.

Presenter (*) 54 Oral Abstracts

Thirty Years of Succession: Changes in Polychaete Dominance in Response to Improving Wastewater Effluent Conditions off Palos Verdes, CA, USA

Lawrence L. Lovell

Marine Biology Laboratory, Los Angeles County Sanitation Districts, 24501 S. Figueroa St., Carson, CA 90743, USA

In anticipation of the Clean Water Act in 1972, the County Sanitation Districts of Los Angeles County implemented a marine monitoring program to collect data and provide long-term monitor- ing of the biological community of the Palos Verdes Shelf in southern California, USA. Initial sam- pling in 1972 revealed a heavily altered benthic infaunal community living in sediments with ele- vated suspended solids, trace contaminants, and high pore water H2S concentrations. Since that time, the Districts‚ have imposed upstream industrial waste source controls, constructed additional treatment infrastructure, and improved treatment processes. These actions significantly reduced the levels of suspended solids, organic loading, and chemical pollutants discharged to the ocean envi- ronment and deposited in nearby sediments. Demonstrated changes in the benthic infaunal commu- nities reflect these improved sediment conditions. Because polychaetes are a major component of the benthic infaunal community they are good indicators of these improved conditions. Literature reports on pollution tolerance, feeding mode, and reproductive strategy for the most dominant poly- chaete taxa are used together with biological data from the Districts, monitoring program to demon- strate a biological basis for the successional changes that have been documented during more than 30 years of monitoring effort. Dominant polychaete taxa addressed include the dorvilleid, Dorvillea (Schistomeringos) longicornis; the capitellids, Capitella capitata complex and Mediomastus spp.; the cirratulids, Aphelochaeta spp. and Monticellina spp.; and the spionids, Spiophanes spp. and Paraprionospio pinnata.

Presenter (*) 55 Oral Abstracts

Evolution of tube coiling direction in the dimorphic Paradexiospira vitrea (Fabricius, 1780) (Sabellida, Spirorbinae)

Tara A. Macdonald

Bamfield Marine Sciences Centre, 100 Pachena Road, Bamfield, BC V0R 1B0, Canada

Although conspicuous bilateral asymmetries are ubiquitous in nature, the inheritance of directional bias is not easily explained: Why should one side be favored over another? The distinctive coiled tubes of spirorbin tubeworms (Sabellida, Spirorbinae) present such a mystery. Most extant species have fixed coiling directions (dextral or sinistral, right- or left-handed). However, some species, such as Paradexiospira vitrea (Fabricius, 1780), are dimorphic. Dextral and sinistral forms of P. vitrea occur in the Northeast Pacific; these are mirror images of each other, but are otherwise mor- phologically identical. Whether this reversal in coiling is the result of developmental plasticity, or is genetic in origin, was the focus of this study. Phylogenetic reconstruction of the evolutionary relationships among dextral and sinistral P. vitrea (based on 400 bp of cytochrome B mitochondrial DNA) revealed sinistral P. vitrea are a distinct clade within dextral P.vitrea. This divergence is cor- roborated by both the 100% heritability of coiling direction, and the ecological segregation of the two forms (sinistral P. vitrea occur in lower densities and are found higher in the intertidal zone). These findings call into question the assumption that coiling direction is often labile in the Spirorbinae, and reports of “situs inversus” may in fact be examples of subspecies divergence.

Presenter (*) 56 Oral Abstracts

Polychaete-Dominated Benthic Infaunal Communities in Massachusetts Bay: Patterns and trends over 15 years of monitoring

Nancy J. Maciolek1* James A. Blake1 & Kenneth Keay2

1 ENSR Marine & Coastal Center, 89 Water Street, Woods Hole, MA 02543 USA 2 Massachusetts Water Resources Authority, Charlestown Navy Yard, 100 First Avenue, Boston, MA 02129, USA

The Massachusetts Water Resources Authority (MWRA) has been discharging treated effluent from the greater Boston, Massachusetts, area into Massachusetts Bay since September 2000. A monitor- ing program was initiated in 1992 to address a series of questions regarding sediment contamination and tracers, and the hard- and soft-bottom benthic communities. An earlier paper (Hilbig and Blake, 2000) discussed the results of the first five years (1992–1996) of baseline data collection on the soft-bottom infaunal benthic communities; this paper considers an additional 10 years of monitoring (1992–2006).

During the baseline period (1992–2000), multivariate analyses of the infauna data suggested that sediment grain size was the dominant factor in structuring the benthic communities. The nearfield stations fall into one of two major sediment regimes: fine sediments characterized by the polychaete annelids Prionospio steenstrupi, Spio limicola, Mediomastus californiensis, and Aricidea catherinae; and sandy sediments characterized by the syllid polychaetes Exogone hebes and E. verugera and the amphipods Crassicorophium crassicorne and Unciola spp. The spionid poly- chaete P. steenstrupi has been the numerical dominant, accounting for as much as 30‚ 59% of the organisms, at medium- and fine-grained stations since 1995, having replaced Spio limicola, which was dominant in 1992–1994.

The farfield stations span a greater depth range (33–89 m) and are geographically more widespread, with sediment types that are generally finer than those in the nearfield. Polychaete worms (e.g., Euchone incolor, Aricidea quadrilobata, and Levinsenia gracilis) are the predominant organisms at most of the stations, although P. steenstrupi is common at some. Another polychaete, Cossura lon- gocirrata, is dominant in Cape Cod Bay, along with E. incolor, which typically indicates the pres- ence of the deep-burrowing holothurian Molpadia oolitica.

Samples collected in 2001–2006, after the outfall went online, have not indicated any discernable impact of the discharge on the infauna. The only change that appears to be directly related to the operation of the outfall is a localized increase in the abundance of the sewage tracer Clostridium perfringens at stations located within 2 km of the discharge. Other changes, such as levels of anthropogenic contaminants and changes in the numbers of certain benthic species, appear to be related to processes such as storm-induced shifts in sediment composition or the natural fluctuations of biological populations.

Presenter (*) 57 Oral Abstracts

Energy maximization strategies of four surface deposit feeding polychaetes: considerations of morphology and function

Heidi K. Mahon* & Daniel M. Dauer

Department of Biological Sciences, Old Dominion University, Norfolk, Virginia 23529, USA

Surface deposit feeders rely on a poor food source and have evolved strategies to maximize net energy gain. This study tested relationship between potential constraints of feeding morphologies and the ability to choose between patches and/or particles of different quality. Two feeding guilds that differed in mobility (potential spatial versus temporal patch selection ability) and particle col- lection morphology (potential particle selection ability within a patch) were studied: a seden- tary/tentaculate guild (the spionid Streblospio benedicti and the terebellid Amphitrite ornata) and a mobile/non-tentaculate guild (the nereidids Neanthes succinea and Laeonereis culveri). We tested two sizes of glass microbeads and two organic coatings. For patch selection, individuals were exposed to homogeneous patches of beads and for particle selection individuals were exposed to a mixture of bead types. Considering patch selection (1) all species selected patches of coated beads over patches of uncoated beads, (2) the sedentary/tentaculate species also selected patches of small beads over patches of large beads, while (3) the mobile/non-tentaculate species showed no size effect between patches. Regarding particle selection (1) Laonereis showed no ability to select parti- cles by coating or size, (2) the other species selected coated beads over uncoated beads, and (3) there were mixed results for particle size with the sedentary/tentaculate species selecting small beads and Neanthes selecting large beads. These results suggest that patch selection (spatio-tempo- ral) is a commonly used strategy among deposit feeders while particle selection may be constrained by particle collection morphology.

Presenter (*) 58 Oral Abstracts

Using nuclear coding genes to tackle difficult problems in annelid phylogeny

Damhnait McHugh1*, N. Schult1, Torsten.H. Struck2, Christoph. Bleidorn3 & Kenneth M. Halanych4

1 Biology Department, Colgate University, 13 Oak Drive, Hamilton, NY 13346, USA 2 Universität Osnabrück, FB05 Biologie/Chemie, AG Spezielle Zoologie, Barbarastr. 11, 49069 Osnabrück, Germany 3 University of Potsdam, Institute for Biochemistry and Biology, Unit of Evolutionary Biology/ Systematic Zoology, Karl-Liebknecht-Str. 24-25, Haus 26, D-14476 Potsdam-Golm, Germany 4 101 Life Sciences Building, Dept. of Biological Sciences, Auburn University, Auburn, AL 36849, USA

A great deal of progress has been made in molecular systematics of polychaetes over the past few years. In particular, combined analyses of genes have been undertaken for comprehensive taxon samples; mitochondrial genomes are being analyzed; and explicit hypothesis testing of sister-group relationships is being used effectively. Monophyly of most families has been upheld, some aberrant taxa have been placed on the annelid tree, and some sister relationships between families have been supported. However, we still lack robust hypotheses for the basal-most extant group on the annelid tree, for the sister group of Annelida, and for relationships among major groups within Annelida. Continued expansion of taxon sampling and further combined investigation of conserved nuclear coding genes, in conjunction with rRNA genes, may help resolve some of these issues. Thus, we are expanding molecular systematic studies of polychaetes to analyses of several nuclear coding genes for comprehensive taxon samples. Specifically, we are collecting and analyzing new sequence data from Elongation Factor-2 (~1400bp), RNA polymerase II (~700bp), Myosin II (~550bp); Clathrin and RRss are also being developed as new data-sets. We are combining our new data with a recent- ly published matrix for Elongation Factor-1?, 18S rRNA and 28S rRNA. We will present the results from analyses of our wide-ranging molecular data sets, focusing on the resolution they bring to deep-level problems in the annelid tree.

Presenter (*) 59 Oral Abstracts

Another one bites the mud: Morphoecological diversification of mandible shape in Pacific methane seep Dorvilleidae

Guillermo F. Mendoza* & L.A. Levin

Scripps Institution of Oceanography, 9500 Gilman Drive, La Jolla, CA 92093, USA

Pacific methane seep sediments host dorvilleid polychaete assemblages that include several unde- scribed species from the genera Ophryotrocha, Parougia, Exallopus and Palpiphitime as well as other previously described species, including the sulfophilic cosmopolitan dorvilleid Ophryotrocha playkephale. Niche partitioning at the microhabitat, environmental (sulfide and oxygen levels) and vertical distribution in the sediment by these dorvilleid assemblages has been studied at the commu- nity, phylogenetic and trophic level. In this study a morphometric approach is explored as a possible method to extract hidden information from the complex variation in dorvilleid jaw structures at the community, population and intra-species level. Two-dimensional outline analysis is used to obtain Fourier coefficients (FC) that act as quantitative proxies of mandible shape. Each shape is com- posed of several FC values that can be used as a multivariate dataset. This data set can be integrated and compared to ecological data such as habitat (microbial mat vs. Calyptogena clam bed), commu- nity composition, and stable isotope signatures (15N and 13C) among others. At the same time the diversification of mandible shape when analyzed using factor analysis can provide information on latent (unmeasured) variables that could be contributing to such diversification.

Presenter (*) 60 Oral Abstracts

Three years seasonal dynamics of the northern Adriatic soft-bottom Polychaete assemblages

Barbara Mikac

Marine Research Centre, Rudjer Boskovic Institute, G. Paliaga 5, 52210 Rovinj, Croatia

Although the taxonomic composition of the northern Adriatic soft-bottom polychaete assemblages is well explored, very little is known about their annual dynamics. Polychaetes were investigated seasonally from March 2003 to December 2006 on three offshore stations in the communities of coastal detritic and muddy coastal detritic bottoms. Sediment samples were collected with 0.1 m2 Van Veen grab and sieved through 2 mm and 1 mm mesh size consequently. Preliminary results of the analyses of 2 mm samples are given—7295 Polychaetes were examined and 141 species belonging to 36 families were identified. This number represents 20% of the known Adriatic Polychaete fauna to date. Comparison with previous investigations indicates relatively rich Polychaete fauna in the research area. Seasonal fluctuation of abundance was different on three sta- tions and did not show periodical pattern but was influenced by the population dynamics of charac- teristic and dominant species. Increase and decrease of abundance was not closely followed by the growth and reduction of species richness. The most abundant species, mutual for three stations, Notomastus latericeus, Owenia fusiformis and Myriochele oculata are characteristic species of detritic and muddy detritic bottoms. Analysis of population dynamics of species Owenia fusiformis and Notomastus latericeus revealed different pattern than in previous research. Reproductive fea- tures of these cosmopolitan species seem to be peculiar to certain population rather then the species itself and depend on different environmental conditions. Low seasonal alterations of structure and dynamics of polychaete assemblages are consistent with the stable environmental conditions during research period.

Presenter (*) 61 Oral Abstracts

Larval development and metamorphic behavior of subtropical spionid Pseudopolydora vexillosa

Flora Mok*, Vengatesen Thiyagarajan & Pei-Yuan Qian

Hong Kong University of Science and Technology, 1/F Coastal Marine Lab, Clear Water Bay, Hong Kong SAR, Guangdong, 852, China

Pseudopolydora vexillosa is one of the conspicuous surface-feeding spioniform polychaetes in sub- tropical waters. This is the first report on the larval growth and metamorphosis of P. vexillosa. Newly hatched larvae of P. vexillosa were able to reach metamorphic competence at 12–17 chaetigers stage when fed with Chaetoceros gracilis or Dunaliella tertiolecta at a concentration of ~104 cells ml-1 for 6 to 8 days at 32 psu and 27oC. Larvae fed with D. tertiolecta or C. gracilis showed no significant difference in percent metamorphosis. On the other hand, larvae fed with I. galbana and 0.22 µm filtered sea water did not reach competence. The effect of organic matter on larval substrate selection was examined using glass beads, manipulated sediments and natural sedi- ments. A significantly higher percentage of larvae metamorphosed on glass beads that has been sub- merged in unfiltered natural sea water for 5 days as compared to the control; when using manipulat- ed sediment as a substratum, a significantly higher percentage of larvae metamorphosed in 100% natural sediment, compared with 0%, 25%, 50%, and 75% natural sediment mixed with different portions of ashed sediment. With natural undisturbed surface sediment as a substratum, which was sampled along a transect perpendicular to a sewage discharge site with a significant decreasing gra- dient of sediment organic carbon and C/N ratio, larvae showed significant preference to organic- poor rather than organic-rich sediments. These bioassays demonstrated that larvae of P. vexillosa are capable of responding to sedimentary cues to find a habitat suitable for metamorphosis and survival.

Presenter (*) 62 Oral Abstracts

The phylogeny of the Terebellidae using morphological data

João Miguel de Matos Nogueira1* & Pat Hutchings2

1 Departamento de Zoologia, Instituto de Biociencias – USP, R. do Matão, travessa 14, n. 101, São Paulo, SP, Brazil 2 Marine Invertebrates, Australian Museum, 6 College Street, Sydney NSW 2010, Australia

The Terebellidae is one of the largest polychaete families with over 60 described genera and over 450 species described, and traditionally has been divided into three sub families. Recent studies using only a suite of species and both molecular and morphological data have only provided limited support for these subfamilies, and the relationships to other families within the Terebelliformia are unclear. In this study we attempted to code the type species of all known genera by examining type material and in some large genera more than a single species has been. For the ingroup, we used four genera and seven species of Polycirrinae, seven genera and 12 species of Thelepodinae, and 41 genera and 42 species of Terebellinae. As outgroups, we included one species of Pectinariidae, two species of Ampharetidae, two species of Alvinellidae and five species of Trichobranchidae. Using an extensive list of 71 characters, including many newly defined ones, we have undertaken cladistic analyses. Although still very preliminary, our results show that Trichobranchidae is paraphyletic with the exclusion of Terebellidae, and the latter is paraphyletic with the exclusion of Alvinellidae and Ampharetidae, which are sister taxa. The clade Terebellidae-Ampharetidae-Alvinellidae is defined by the presence of thoracic avicular uncini. Within this clade, relationships are still unclear, resulting in a big polytomy, with most groups monotypic, a few small subclades, one of which con- taining the Alvinellidae-Ampharetidae clade, and two large monophyletic clades, one of which con- taining the Polycirrinae and the other, the Terebellinae with distally serrated notochaetae, independ- ent on the type of distally serrated notochaetae. The study will proceed, trying to find additional characters, especially in regards to the types of distally smooth notochaetae, as an attempt to get a better resolution. We will discuss these results and compare them with previous classifications.

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Presenter (*) 63 Oral Abstracts

Comparison of morphology and molecular analyses of diversity in abyssal polychaetes from the Central Pacific manganese province

Gordon Paterson1*, Iris Altamira2, Craig Smith2, Pat Dyal, Joelle Galeron3, Lenaick Menoit3, Markus Böggemann4, Robin Floyd5, Alex Rogers6 and Adrian Glover1

1 Department of Zoology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK 2 University of Hawaii at Manoa, 1000 Pope Rd., Marine Sciences Building, Honolulu, HI 96822, USA 3 IFREMER, Brest, France 4 Universität of Osnabrück, FB 5 Zoologie, Barbarastrasse 11, D-49069 Osnabrück, Germany 5 British Antarctic Survey, Cambridge UK 6 School of Electronics and Computer Science, University of Southampton, Southampton, SO17 1BJ, United Kingdom

The polychaete assemblages of the manganese nodule province of the Clipperton–Clarion Fracture Zone (CCFZ) were studied as part of a large-scale biodiversity assessment. The aim of the study was to determine distribution patterns and scales of endemism within the province. The information generated will be used to assist with the development of sustainable management plans for the International Seabed Authority. Both morphological and molecular methods were used to assess numbers of species across a number of sites within the CCFZ. Families studied were the Lumbrinereidae, Glyceridae, Syllidae Spionidae and Cirratulidae. These families also cover a range of trophic groups. Initial results suggest that many species are morphologically similar over dis- tances >500 km but molecular analyses point to cryptic speciation within a range of families. The implications of these findings in terms of the evolution of abyssal fauna and for sustainable man- agement will be discussed.

Presenter (*) 64 Oral Abstracts

Phylogeny of Eunicida based on morphology of jaws

Hannelore Paxton

Department of Biological Sciences, Macquarie University, Sydney NSW 2109, Australia

Eunicida have a complex jaw apparatus with a fossil record dating to late Cambrian. Traditionally, Eunicidae, Onuphidae and Lumbrineridae were considered closely related families having labidog- nath maxillae, whereas Oenonidae with prionognath type maxillae were thought derived. A recent molecular phylogeny of Eunicida placed Oenonidae with Eunicidae (incl. Onuphidae), while Lumbrineridae was considered the most basal taxon (Struck et al. 2006). Morphological evidence is presented to support a sister group relationship between Eunicidae/Onuphidae and Oenonidae. Although Lumbrineridae share some characteristics with Eunicidae/Onuphidae, they are not of the labidognath type. Homologies of jaw elements and considerations of functional aspects of the jaw apparatus of extinct and extant representatives are explored to present a hypothesis of the phylogeny of Eunicida. The earliest fossils are of the placognath and ctenognath types, lacking maxillary carri- ers. While the former are extinct, the latter are represented by Dorvilleidae. The evolution of carri- ers provided areas for muscle attachment and allowed eunicidans to attain more efficient mobility and coordination of the jaw apparatus. A small jaw element, the basal plate, provides a clue to the evolutionary history of the three derived lines. The Lumbrineridae lost the basal plate and are now characterized by paired elements. The Oenonidae and Eunicidae/Onuphidae sister group acquired an additional unpaired element (left MIII) and retained or fused the basal plate with the right forceps (MI). The prionognath oenonid jaw apparatus is functionally simpler, while that of the labidognath eunicid/onuphid type with its additional articulation structures is the most efficient type.

Presenter (*) 65 Oral Abstracts

Cosmopolitan species: Facts, artifacts, or both?

Mary E. Petersen

Darling Marine Center, University of Maine, 193 Clarks Cove Road, Walpole, ME 04573, USA

A 1974 oil spill in West Falmouth, SW Cape Cod, proved to be a death blow to the concept of cos- mopolitan species. Up to 1976, when Grassle & Grassle published their now classical paper (Science 192: 567–569) on recolonization after this spill Capitella capitata (Fabricius, 1780) was believed to be a well known marine pollution indicator “found in every part of the world where marine benthic studies have been conducted” (Grassle & Grassle 1976). The oil-spill study changed that belief. Instead of one species, they found six, similar but differing in morphology, life history, reproductive mode, and electrophoretic patterns for eight enzymes. Only one of the six species was described. Since then, closer examination of other purportedly cosmopolitan species, e.g., Terebellides stroemii Sars, 1835 and Chaetopterus variopedatus (Renier, 1804), has shown similar results. This has obvious consequences for biodiversity, which has been underestimated, and sug- gests that truly cosmopolitan species may not exist. Some species still considered cosmopolitan are presented in hopes that persons with access to live material will take a closer look at the species. Features shared by many “cosmopolitan” species are mentioned. Some simple nonpermanent stains that enhance details, thus enabling more accurate descriptions and comparisons, are described, and for existing or new cosmopolitan species, three routes to achieving this status are suggested. Finally, “cosmopolitan” has become a word with no precise meaning and not differing from “widespread”. Agreement on a minimum presence in XX major bodies of water would mean that we could com- municate more precisely.

Presenter (*) 66 Oral Abstracts

Morphology of elytra as luminescent organs in scale worms (Polychaeta, Polynoidae)

Maria Plyuscheva1*, Mikhail Vyssokikh2 & Daniel Martin1

1 Centre d’Estudis Avançats de Blanes (CEAB-CSIC), c/ Accés a la Cala Sant Francesc 14, 17300 Blanes Girona, Spain 2 Lomonosov Moscow State University, Leninskie Gori, 1-40, Moscow 119992, Russia

Polynoid polychaetes are common marine invertebrates worldwide, from Antarctic to Arctic, from intertidal to deep waters (i.e. abyssal and hadal depths), and from soft to hard bottoms. They are characterized by bearing series of paired elytra attached to dorsal prominences (the elytrophores) arising from the notopodia, which dorsal surface is usually ornamented with different papillae (usu- ally thought to be sensory organs).

Upon stimulation, some species of the sub-family Polynoinae are able to emit light flashes from the ventral epithelium of the elytra. This bioluminescence originates in a protein called polynoidin, and seems to be induced by the destruction of the electrochemical coupling between body and elytra when the latter are detached. Although it was suggested that the signal could be a warning or anti- predator mechanism, its real behavioral or ecological function remains unknown. Moreover, the ely- tral structure, as well as the function of the papillae and tubercles in relation to the biolumescence is poorly known.

The elytral morphology of four “luminescent” and two “non-luminescent” (Nicol, 1953) species from the White and Mediterranean Seas has been studied. In both polynoid types, the elytral tuber- cles are formed by a layer of hard, non-organized, autofluorescent tissue, apparently filled by expansions protruding from cells forming a distinct subjacent layer. Therefore, we suggest that the luminescent protein is located in the cells of the basal layer, while the tubercles may act as lenses helping in the light flash transfer towards the exterior. The reasons why some species are biolumi- nescent and some not are discussed.

Presenter (*) 67 Oral Abstracts

Evolution of reproduction in Spionidae (Annelida)

Vasily I. Radashevsky

Russian Academy of Sciences, Institute of Marine Biology, Palchevsky Str. 17, Vladivostok 690041, Russia

Two opposed hypotheses have been provided on the evolution of reproduction in Spionidae. One of them considers oocytes with thin and smooth envelope as a plesiomorphic character shared by Spioninae members and many other polychaetes, and the oocytes with thick sculptured envelope as a derived character evolved within Spionidae (Söderström, 1920). Another hypothesis suggests that thick-envelope oocytes evolved in a primary spionid and thin-envelope oocytes evolved in Spioninae due to the reduction of the original thick envelope in connection with the evolution of brooding (Hannerz, 1956). A cladistic analysis of morphological, ecological and reproductive char- acteristics of Spionidae rooted with the paraonid Aricidea antennata was performed to establish a hypothesis of the evolution of reproduction in Spionidae. The results of the analysis suggest that the first spionid was a free-living in sediment and gonochoristic polychaete that had branchiae on most segments, cirri-form pygidium and uniform metanephridial segmental organs distributed throughout body, except the first three segments. These worms produced oocytes with thick sculptured enve- lope and ect-aquasperm with subspherical acrosome, spherical nucleus, and four external spherical mitochondria. They released gametes into water where fertilization and entirely planktotrophic lar- val development occurred. The oocytes with thin and smooth envelope and brooding evolved not in the nearest ancestor of Spioninae but in an ancestor of a clade that includes Rhynchospio and Spioninae. Similar mode of reproduction evolved independently in an ancestor of Streblospio, thus thin-envelope oocytes and brooding are homoplasious characteristics resulted in a parallel evolution in two different clades of Spionidae.

Presenter (*) 68 Oral Abstracts

Reproductive Longevity in Two Species of Polychaetous Annelids

Donald J. Reish*, Karin DeCallibus, Jessica Dewar & Cheryl Bube

Department of Biological Sciences, California State University, Long Beach, Long Beach, CA 90840, USA

Polychaetes reproduce in a wide variety of methods. Some species reproduce once then die. Others produce stolons which disperse gametes in the water column with the parent surviving. Others reproduce asexually. Regardless of the method of reproduction very little is known on how long an individual, which reproduces multiple time, can live. In attempt to answer this question two species of laboratory reared polychaetes, Dinophilus gyrociliatus and Neanthes arenaceodentata, were selected for this study. Dinophilus gyrociliatus is a minute species which lays two sizes of eggs within a capsule. The smaller egg develops into a male and fertilizes the larger sized female egg within the capsule then dies. The experiment was initiated as soon as the hermaphroditic worms emerged from the capsule at 4 days. Initial capsules and eggs, generally numbering 3-5 larger and 1-2 smaller, were laid five days later. The maximum number of capsules and eggs occurred during the first three egg laying periods then decreased thereafter. The oldest worm lived 69 days. The female N. arenaceodentata lays her eggs then dies. The male incubates the embryos for 21-25 days and is capable of reproducing again. One male reproduced nine times, but the eggs were not fertil- ized the eighth or ninth time. He died shortly afterwards having lived 13 months. Dinophilus was capable of reproducing successfully up to death, but apparently Neanthes males live beyond their ability to fertilize eggs.

Presenter (*) 69 Oral Abstracts

The cosmopolitan species, Polydora cornuta (Polychaeta: Spionidae) is composed of at least three genetically distinct and reproductively isolated lineages in North America.

Stanley A. Rice* & Stephen Karl

University of Tampa, 401 W. Kennedy Blvd., Tampa, FL 33606, USA

Three geographically separated populations of Polydora cornuta Bosc 1802 were raised in the labo- ratory and assessed for reproductive compatibility, genetic similarity, gamete characteristics, and developmental rates. P. cornuta were collected from Florida, California, and Maine. Reproductive crosses between each combination of sex and population revealed variable levels of hybridization at fertilization. Percent fertilization in each inter-population cross was found to be very low (0–7%) with the exception of California females crossed with Florida males (42%). In this cross and all other inter-population crosses, no viable larvae were produced and fertilized eggs arrested in cleavage. Among ten reproductive characteristics assessed, Florida worms were significantly different from California worms in seven characters and Florida differed significantly from Maine in five character- istics. California and Maine were significantly different in five of ten parameters measured. Florida worms were significantly different from California and Maine in the location of the first gamete- bearing segment in both males and females, and in the length of the mature sperm. Mitochondrial cytochrome oxidase subunit I (CO1) sequences revealed large differences between Florida and California worms with a maximum likelihood genetic distance of d = 0.860, while Florida and Maine worms were d = 0.806, and California and Maine d = 0.156. A sample of preserved P. cornuta speci- mens from New Zealand was found to be very similar to the sequences from California worms (d = 0.010). The collective data strongly suggests that Polydora cornuta in North America is actually a cryptic species complex composed of at least three phylogenetically separate lineages.

Presenter (*) 70 Oral Abstracts

Phylogeny and systematics of Histriobdellidae (Eunicida, Annelida)

Greg Rouse

Marine Biology Research Division 0202, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093, USA

Histriobdellidae is a small taxon in the annelid clade Eunicida, with 12 described species, most of them from freshwater. The presence of palps and antennae and distinctive jaws clearly places histri- obdellids as part of Eunicida, but their precise location is unresolved. Histriobdellids have a fasci- nating geographical distribution, mainly in the southern hemisphere, and all are symbionts with crustaceans, mainly freshwater decapods, though one is associated with a marine intertidal isopod. Currently there is one marine species placed in Histriobdella, while 10 freshwater species are in Stratiodrilus. One marine species, Stratiodrilus haswelli, was recently transferred from Stratiodrilus to a new genus, Dayus, which is unfortunately a junior homonym. Various freshwater Stratiodrilus species were collected from Australia, Madagascar and South America. Histriobdella homari speci- mens were obtained from American and European specimens of Homarus and the marine Stratiodrilus haswelli was collected from intertidal isopods in South Africa. A dataset based on mor- phology and nuclear and mitochondrial DNA was analyzed using maximum parsimony and Bayesian methods. The analyses support a single colonization event to freshwater in Histriobdellidae and hence that the freshwater Stratiodrilus species form a clade. The removal of Stratiodrilus haswelli to a new genus is supported and the erection of new species in Stratiodrilus and Histriobdella is warranted. The historical biogeography of histriobdellids, as well as the co-evo- lution with their crustacean hosts is also discussed.

Presenter (*) 71 Oral Abstracts

Phylogeny of Terebelliformia and the evolution of key features

Vincent Rousset1*, Fredrik Pleijel2 & Greg Rouse1

1 Marine Biology Research Division 0202, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093, USA 2 Göteborg University, Tjärnö Marine Biological Laboratory, SE-452 96 Strömstad, Sweden

Terebelliformia is a group of annelids with multiple grooved palps that is currently comprised of the following family-ranked taxa: Alvinellidae, Ampharetidae, Pectinariidae, Terebellidae and Trichobranchidae. The group contains taxa with fixed segment numbers (e.g. Pectinariidae) or fixed numbers of segments in certain areas (e.g. the thorax). There have been several investigations in recent years into the overall phylogeny of Terebelliformia. These have used various combinations of molecular and/ or morphological data and the results have been somewhat conflicting. To further assess the phylogeny of Terebelliformia and to investigate the evolution of features such as segmen- tation patterns, we assembled an extensive set of exemplars of tebelliforms. We then used parsimo- ny, maximum likelihood and Bayesian inference approaches to reconstruct Terebelliformia phyloge- ny using morphological and DNA sequence data from two nuclear ribosomal genes (18S rDNA and the D1 region of 28S rDNA), one nuclear protein-coding gene (Histone H3) and two mitochondrial loci, one protein-coding (cytochrome c oxidase I) and one ribosomal (16S rRNA). The status of the five family-ranked taxa and their subfamilies (where relevant) is discussed, as well as the evolution of various key morphological characters. A resolution of the conflicting terminology for the thoracic and abdominal regions is proposed.

Presenter (*) 72 Oral Abstracts

Submarine canyons as habitats for speciation: some ecological remarks

Rafael Sarda*, João Gil, Sergi Taboada & Josep Maria Gili

Centre d’Estudis Avançats de Blanes (CEAB-CSIC), c/ Accés a la Cala Sant Francesc 14, 17300 Blanes Girona, Spain

Sediment traps were placed in the water column both inside and in the vicinity of the Planier and Lacaze-Duthiers (France) and Foix (Spain) submarine canyons. Polychaetes were obtained frequent- ly at all sample stations but they were much more frequent inside the canyons than in the vicinity of them. The rich collection of polychaetes obtained in the traps lead us to postulate that those ani- mals were supported by a continuous flux of organic matter and they were adapted to the strong physical conditions that may occur inside canyons. Presence in the traps peaked in March and mir- rors the seasonal presence of Ophelina margaleffi. When Ophelina margaleffi was not considered, a mayor presence of polychaetes was detected in fall.

In very active and energetic systems such as exist near the sediment surface layers; physical and ecological conditions can create special habitats where the relationships between particle flux and species are constant. Materials in the canyons can be transported by resuspension associated with strong high-velocity bottom currents and violent episodic events, then, some endo- and epi-benthic species can be easily mobilized into the water column, together with benthopelagic and even plank- tonic species, producing what could be considered as a sediment-water soup. These conditions could have forced species to evolve in a way to improve their adaptation to the particular conditions of such habitats. This is probably an extremely interesting little-studied habitat. Habitats inside sub- marine canyons are also isolated from deep open-water and hence could enhance speciation of organisms that inhabit their near-bottom layers.

Presenter (*) 73 Oral Abstracts

Polydorid species (Polychaeta, Spionidae) in southwestern Australian waters

Waka Sato-Okoshi1*, Kenji Okoshi1 and Jeremy Shaw2

1 Tohoku University, 1-13-1-501, Kitane, Aoba-ku, Sendai 981-8555, Japan 2 Murdoch University, Perth, Western Australia

Eight species of polydorid polychaetes were found to bore into molluscan shells from southwestern Australian waters. Numerous polydorids were extracted from the shells of both land based cultured abalones and natural subtidal abalone and other gastropods. Shells of the oyster cultured in sea based systems were infested by polydorids in these waters. Biology of these polydorids are dis- cussed. This study suggests that further monitoring of polydorid species is needed not only from the viewpoint of marine biology but also to survey the risk invasive species pose to commercially important molluscs in this region and worldwide.

Presenter (*) 74 Oral Abstracts

The Petrosia syllid: a new shallow water species of branching polychaete with polymorphic segments

Paul C. Schroeder1* & Christopher J. Glasby2

1 School of Biological Sciences, Washington State University, Pullman, WA 99164, USA 2 Museum & Art Gallery of the Northern Territory, GPO BOX 4646, Darwin NT 0801, Australia

A branching syllid has been recovered from specimens of Petrosia sp. in Darwin Harbor, NT, Australia. These haplosclerid demosponges occur from the low intertidal to at least 30 m.; the syl- lids branch extensively through the canal system of the sponge and many posterior ends are visible and active on the surface of intact sponges. Dissection of preserved sponges revealed that the poste- rior ends occur as tufts of distinctive, pigmented posterior segments, connected by elongate, color- less segments and segments of intermediate morphology. Many stolons are produced on short seg- mental “stalks” produced by branching. Most are female and lack capillary chaetae. Male stolons have not been positively identified. Comparison of the Petrosia syllids with Japanese specimens of Syllis ramosa from a hexactinellid sponge collected from Sagami Bay, Japan, and with the original Challenger specimens (McIntosh, 1885) showed that they differ significantly. The new worm lacks the compound or pseudocompound chaetae characteristic of the genus Syllis; they are instead sim- ple, with two laterally directed fangs, resembling more those of Haplosyllis. The dorsal cirri are shorter and have fewer articulations than those of S. ramosa. Japanese specimens of S. ramosa are rose-red in life Imajima (1966); the Petrosia syllid has unpigmented interior segments; the posterior dorsal cirri are maroon, but white on the most posterior external segments. McIntosh (1885) illus- trated stolons of both sexes of S. ramosa, both of which included capillary chaetae. Although the complex branching morphology and form of the chaetae suggest that the Petrosia syllid is parasitic, the morphology of the head with three antennae, 2 pairs of eyes, medially separated palps and 2 pairs of tentacular cirri resembles that of free living forms. Further studies of this fascinating poly- chaete are in progress.

Presenter (*) 75 Oral Abstracts

Biodiversity and composition of polychaetes from the Atlantic sector of the deep Southern Ocean- results from the expeditions ANDEEP I-III (austral summer 2002 and 2005)

Myriam Schüller* & Brigitte Ebbe

ZFMK Bonn, Spezielle Zoologie, Ruhr Universität, Universitätsstr. 150, 44801 Bochum, Germany

During the course of two expeditions to the Atlantic sector of the Southern Ocean 29 epibenthic sled (EBS) samples were taken from sites near Cape Town, South Africa along a transect across the Weddell Sea, and around the Antarctic Peninsula and the South Sandwich Trench. Within these samples over 14,000 polychaete specimens were found belonging to 47 different families. During an extensive morphological study over 6,000 polychaete specimens from 13 families were identified to species level. The resulting data provided a detailed assessment of the polychaete composition of the sampled sites. Almost 50% of all species identified were new to science pointing out that, despite recent efforts, the deep sea is still a strongly undersampled part of the Southern Ocean. Different biodiversity measures were applied supporting the hypothesis that the deep Southern Ocean hosts a highly diverse polychaete fauna. Local differences in community structure between the sites could be discovered resulting from different depths and environmental factors.

Presenter (*) 76 Oral Abstracts

Developmental mechanisms of segment formation

Elaine C. Seaver* & Katrin Thamm

Kewalo Marine Lab, University of Hawaii, 41 Ahui Street, Honolulu, HI 96813, USA

Among the major segmented clades of animals, the Chordata, Arthropoda and Annelida, annelids exhibit the most extensive variability in segment formation across species. This variability includes differences in number of segments, segment fusion, and the ability to generate segments at multiple life history stages. For example, many polychaetes can continually add segments during adult life, regenerate lost segments, and some species have undergone segment loss. We are investigating the developmental mechanisms by which segments are generated in these different contexts, with the goal of making inter-taxonomic comparisons to understand the evolution of segment formation in the Bilateria. To date, we have primarily focused on the generation of larval segments in Hydroides elegans, Chaetopterus sp., Platynereis dumerilii and Capitella sp. I, and have investigated whether the molecular mechanisms utilized in segment formation in chordates and arthropods are involved in annelid segment formation. We have performed a more detailed study in Capitella sp. I, whose genome has been completely sequenced (JGI, DOE). Cumulative evidence from our work and oth- ers does not support the presence of a common genetic network regulating segmentation between annelids and arthropods, although historically annelids and arthropods were thought to share a com- mon segmented ancestor. In contrast, our results are suggestive that the mechanisms utilized in for- mation of vertebrate somites may be involved in segment formation from the posterior growth zone in Capitella sp. I juveniles. The evolutionary implications of our findings will be discussed.

Presenter (*) 77 Oral Abstracts

Temporal variability in polychaete assemblages of the abyssal NE Atlantic Ocean

Eulogio Soto1,2*, Gordon Paterson3, David Billett2, Lawrence Hawkins2, Joelle Galeron4 & Myriam Sibuet4.

1 University of Valparaiso, Avenida Borgoño 16344 Montemar Reñaca, Viña del Mar, Valparaiso, Casilla 5080 Reñaca, Chile, 2 National Oceanography Centre, Southampton University, 21 Ashwood Drive, Broadstone, Dorset, BH18 8LN, UK 3 Department of Zoology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK 4 IFREMER, Brest, France

Temporal variability in deep-sea polychaete assemblages was assessed over a 9-year period between August 1989 and September 1998 from Porcupine Abyssal Plain, NE Atlantic Ocean. The poly- chaete communities were characterized by high abundance and high family richness. The most abundant families were the Cirratulidae, Spionidae, Opheliidae and Paraonidae. Surface deposit- feeders were the dominant trophic group (67.4% of total abundance). Significant temporal variabili- ty was evident in polychaete abundance with significant differences in polychaete abundance between cruises (p<0.01). There was a stepwise increase of abundance in September 1996 and March 1997 coinciding with similar increases in abundance in large invertebrates (megafauna) in the same area. A similar trend was observed for densities within different layers of the sediment, main families and trophic groups with statistical analyses showing significant differences between cruises (p<0.05). Not all elements of the polychaete community showed a response. Numbers with- in the deeper layers, 3-5cm and in some families such as the Paraonidae did not show significant difference either between cruises. This points to the polychaete response being lead by a particular element of the fauna, primarily the surface deposit feeders. Further analyses of the species level response will be presented. The temporal variability observed in this grouping of the polychaete communities is likely to be related to seasonal and interannual variability in organic matter input. Greater food supply in some years allowed for the growth and development of abundant deposit- feeding polychaete populations.

Presenter (*) 78 Oral Abstracts

Evolutionary history of dorvilleid annelids associated with methane seep environments

Daniel J. Thornhill1*, Torsten H. Struck2, Brigitte Ebbe3, Guillermo F. Mendoza4, Lisa A. Levin4 & Kenneth M. Halanych1

1 101 Life Sciences Building, Department of Biological Sciences, Auburn University, AL 36849, USA 2 Universität Osnabrück, FB05 Biologie/Chemie, AG Spezielle Zoologie, Barbarastrasse. 11, 49069 Osnabrück, Germany 3 Forschungsinstitut Senckenberg, DZMB, c/o Forschungsmuseum König, Adenauerallee 160, D- 53113 Bonn, Germany 4 Scripps Institution of Oceanography, 9500 Gilman Drive, La Jolla, CA 92093, USA

Along the Oregon and California margins, methane seeps have low oxygen levels and very high hydrogen sulfide levels. Although such conditions render these environments inhospitable to most animal life, dorvilleid annelids thrive there. Observations at Eel River, California and Hydrate Ridge, Oregon methane seeps have numerous species of dorvilleids, including Ophryotrocha, Parougia and Exallopus species, associated with bacterial mats and Calyptogena clam beds. The sympatric presence of many closely related taxa indicates that these dorvilleid lineages may have experienced diversification at methane seeps. To address the recent evolutionary history of these annelids, we have undertaken a molecular phylogenetic study employing the mitochondrial 16S rDNA and cytochrome b genes. Our results indicate that more dorvilleid diversity exists than is currently recognized by morphology. Some reconstructed clades indicate fidelity between lineages and habitat, sediment depth, and/or geography; this partitioning may help to explain the diversity of confamilial taxa present at these methane seeps. In contrast, other clades are composed of individu- als from multiple habitats across the region, suggesting that some lineages of these small infaunal organisms are generalists with good dispersal capabilities. Larger implications for the evolutionary history of this group, including the evolution of sexual strategies and the evolutionary plasticity of inhabiting methane seep environments, are also discussed.

Presenter (*) 79 Oral Abstracts

Transformations of axial non-muscular pharynx in Polychaeta

Alexander B. Tzetlin* & Anna E. Zhadan

Moscow State University, Biological Faculty, Leninskie Gory, 1-12, Moscow 119992, Russia

Non-muscular axial pharynx is characteristic for several polychaete taxa now referred to Scolecida clade Capitellidae, Arenicolidae, Maldanidae, Opheliidae, Scalibregmatidae, Paraonidae and Orbiniidae. According to the traditional view to the construction of the organ it is represented by an axial soft sac-like structure adopted mainly for ingestion of the sediment. In the same time, in the family Opheliidae, some aberrant cases of soft axial proboscis are known, like the tongue-like or tentacular structures (some species of the Ophelininae). Pharyngeal structures of 17 species from Opheliidae, Scalibregmatidae and Orbiniidae were studied using SEM and light microscopy. It was found that all studied representatives of Orbiniidae, Scalibregmatidae and subfamilies Opheliinae and Travisiinae have true soft axial pharynx, covered by ciliated epithelium. In all studied Ophelininae the pharynx is assymetrical. Only the dorsal part of the pharynx is eversible, so the digestive tract goes ventrally from it.

In Ohelina acuminata, O. nematoides, Armandia brevis, Polyophthalmus pictus the pharynx is transformed to the dorsal ciliated tongue-like organ. In Armandia maculata pharynx also changed and form about 15 dorsally rooted ciliated tentacles. Tentacular pharyngeal structures were described for few more species of Ophelininae. Dorsal ciliated tentacles are known in Cossuridae – another family referred to Scolecida. Possibly, the tentacular pharyngeal organ in Cossuridae evolved from the non muscular axial pharynx typical for other families still referred to Scolecida. Evolutional pathways of the soft axial pharynx in Polychaeta are discussed.

Presenter (*) 80 Oral Abstracts

Using molecular data to interpret ecological gradients: an interface between genetics and ecology

Katerina Vasileiadou*, E. Sarropoulou, K. Tsigenopoulos, S. Reizopoulou, A. Nikolaidou, S. Orfanidis, M. Simboura, G. Kotoulas & C. Arvanitidis, C.

HCMR-IMBG, P.O.Box 2214, Heraklion, Crete 71003, Greece

Lagoons are shallow water bodies, semi- or completely isolated from the sea by sediment barriers, strongly influenced by adjacent sea, rivers and coast. Their small depth seems to be an important factor for temperature and salinity temporal and spatial variations, which are responsible for popula- tion fluctuation. Macrobenthic communities, show low species diversity, a result of the response (/adaptation) of a few species to severe and highly variable conditions. Therefore, lagoons are a tempting field for the study of genetic adaptations and community behavior to extreme environmen- tal conditions. Polychaetes, is the most important macrobenthic taxon in terms of diversity and abundance, in the lagoons of Amvrakikos Gulf (NW Greece). Additionally, they are considered as well studied and they provide a good estimate of the benthic community showing similar trends to those produced by the total macrobenthic fauna. Until recently, faunal taxa were studied separately by ecologists and population geneticists. However, using molecular data deriving from multispecies assemblages in order to test ecological theory has only recently been proposed in the scientific liter- ature. As a first step, a comparison of the faunal patterns deriving from polychaete lagoonal taxo- communities to those deriving from molecular data from those species is attempted in the course of this study. For this reason, mtDNA of the most abundant polychaetes from the Amvrakikos Gulf lagoons were used. Non-metric multidimensional scale (MDS) analysis was used to represent species and genetic diversity patterns, while 2nd stage MDS analysis was used for the comparison of the aforementioned patterns.

Presenter (*) 81 Oral Abstracts

Biomineralization and evolution of calcareous tubes in polychaetes

Olev Vinn1* & Harry A. ten Hove2

1 Geoloogis Instituut, University of Tartu, Vanemuise 46, Tartu, Estonia 2 Zoological Museum Amsterdam, University of Amsterdam, P.O.B. 94766, 1090 GT Amsterdam, Netherlands

Calcareous tubes occur in the polychaete families Serpulidae, Sabellidae and Cirratulidae. Only ser- pulids exclusively have calcareous tubes. According to the traditional palaeontological view the ear- liest polychaetes with calcareous tubes were serpulids, appearing already in the early Paleozoic (~460 Mya). In contrast to this traditional view, we support a geologically much younger Mesozoic age for the serpulids. Studies of fossil and recent tube ultrastructure of various worm-like groups make us believe that the first serpulids appeared in the Early Mesozoic (Vinn et al., in press), older worm-like fossils belong to for instance the Microconchida (Lophophorata). Most likely calcareous tubes evolved at least three times independently in polychaetes: first in serpulids (in the Triassic, ~240 Mya), then in sabellids (Jurassic, ~180 Mya) and most recently in cirratulids (Oligocene, ~30Mya).

Polychaete biomineralization systems support both CaCO3 polymorphs- aragonite and calcite. Serpulids of mixed composition are very common. Most single layered serpulid tubes are also bimineral, with the exception of completely calcitic prismatic tubes of Placostegus tridentatus and Vitreotubus digeronimoi. Calcareous tubes of sabellids and cirratulids are presumably exclusively aragonitic.

Complex tube structures have evolved exclusively in serpulids. In this respect they are more similar to the molluscs than to the cirratulids and sabellids. In contrast, sabellids and cirratulids have very simple aragonitic spherulitic prismatic tube ultrastructures which have remained unchanged form the Jurassic and the Oligocene respectively.

Presenter (*) 82 Oral Abstracts

Influence of host presence on the palp growth of the commensal worm Dipolydora commen- salis (Polychaeta: Spionidae)

Jason D. Williams*& Lara D. Luzak

Hofstra University, Department of Biology, Hempstead, NY 11549, USA

Dipolydora commensalis (Andrews, 1891) is an obligate commensal of hermit crabs. The species bores into gastropod shells occupied by hermit crabs, forming a burrow that extends from an open- ing on the columella toward the apex. The feeding biology of D. commensalis is not fully under- stood but the worm is known to feed on suspended particles and food particles dropped by the host hermit crab. Interestingly, although D. commensalis attains large sizes, the species has very short palps (generally <1.0 mm) as compared to other members of the genus Dipolydora with palps up to >8 mm. The morphology of the palps was compared between two groups of D. commensalis col- lected from Long Island, NY: specimens that were fixed immediately upon removal from hermit crab shells collected in the field and specimens that were isolated in glass capillary tubes and main- tained in the laboratory for >60 days. Mean palp lengths of specimens isolated from hermit crabs increased 71.5% from 1.0 mm ± 0.5 (n=39) to 1.7 mm ± 0.7 (n=29). Palp length relative to body length at 14 days after isolation was significantly different from initial palp to body length ratios. Examination by scanning electron microscopy showed signs of abrasion on both female and male worms fixed upon removal from the shell. This research suggests that contact between D. commen- salis and its hermit crab host is the mechanism responsible for the short palps of the worms.

Presenter (*) 83 Oral Abstracts

Biogeographic patterns among Nereididae (Polychaeta) in Australia

Robin Wilson1* & Chris Glasby2

1 Museum Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia 2 Museum & Art Gallery of the Northern Territory, GPO BOX 4646, Darwin NT 0801, Australia

The Nereididae is perhaps the most suited of all polychaete families for analysis of biogeographic patterns in Australian waters. Nereidids occur in marine, estuarine and freshwater habitats; they are often the most conspicuous, diverse and widespread polychaetes. The Nereididae fauna of shelf and inshore waters of Australia is well known and comprises about 160 described species which we now know from over 7,500 point distribution records. Recent phylogenetic studies are used to construct a meta-tree which we present as the best available hypothesis of phylogenetic relationships within the Nereididae. Quantitative biogeographic methods are used to analyse and describe biogeographic pat- terns for Australian Nereididae and propose historical explanations for those patterns. The Simplisetia group, which is confined to estuaries and to embayments that were estuarine within the last 8,000 years, is apparently a local radiation. A clade containing Ceratonereis, Cheilonereis, Leonnates and Solomononereis probably has tethyan origins and represents a post gondwanan addi- tion to the Australian nereidid fauna. Collections from depths exceeding 200 m contain only 3 nerei- did clades: Neanthes kerguelensis and relatives; Nicon spp.; and Ceratocephale spp. Australian Nereididae reach their greatest species richness in southern inshore waters on hard substrates, where at least 5 distinct clades contain multiple species: (Platynereis; Nereis; Neanthes vaalii and relatives; Perinereis vallata and relatives; Perinereis amblyodonta and relatives). The monophyly of these taxa, and phylogenetic relationships within them, remain unclear. We cannot yet say whether these clades contain mostly local radiations or species with sister taxa on other continents.

Presenter (*) 84 Oral Abstracts

Arenicolid Behavior and Impact: Arenicola marina versus Abarenicola pacifica

Sarah Ann Woodin* & David S. Wethey

Dept. of Biological Sciences, University of South Carolina, 715 Sumter Street, Columbia, SC 29208, USA

The arenicolid polychaetes Arenicola marina and Abarenicola pacifica are dominant ecosystem engineers of shallow sedimentary environments of the north Atlantic and north Pacific respectively. They alter habitats by subduction of surface material to depth, turnover of sediments, and increase in porewater flux rates. Their life habits appear to be very similar with regard to burrow type, feed- ing, etc. although Arenicola marina is a much larger animal. To ask whether their behavioral reper- toires in the sense of frequency, magnitude, and sphere of influence are similar, we analyzed their behaviors both in the field and in the laboratory using pressure sensors and video. In general the similarities are more striking than the differences.

Presenter (*) 85 Oral Abstracts

Muscle and nervous system of the meiofaunal Diurodrilus (Diurodrilidae, Annelida): recon- structed by phalloidin- and immunostainings, CLSM, and TEM.

Katrine Worsaae1* & Greg W. Rouse2

1 Marine Biological Laboritory, University of Copenhagen, Strandpromenaden 5, DK-3000 Helsingør, Denmark Marine Biology Research Division 0202, 2 Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093, USA

Diurodrilus Remane includes six species described from tidal to subtidal sand bottom in the North Atlantic, the Mediterranean, and the North Pacific. They are all meiofaunal (length up to 450um), hyaline, dorso-ventrally flattened, slightly elongated, acoelomate metazoan inhabitants of the inter- stitial marine environment between sandgrains.

Diurodrilus minimus Remane was originally assigned to Dinophilidae within the so called “Archiannelida.” Diurodrilidae and Dinophilidae are presently considered to be highly derived, sec- ondarily reduced, annelid families, or even to lie within Dorvilleidae. However, Diurodrilus lacks all major annelid characteristics such as chaetae, appendages, parapodia, and nuchal organs as well as paedomorphic characters. Diurodrilids even lack a midventral ciliary band, characteristic of inter- stitial annelids such as Dinophilidae. Diurodrilus instead possess unique specializations of cilio- phores, duo-glands and spermatozoa.

In the present study muscle and nervous system of three species of Diurodrilus were stained with phalloidin and antisera directed against serotonin (5-HT), FMRF-amid, and acetylated ? tubulin and investigated with confocal laser scanning microscopy, as well as transmission electron microscopy. Diurodrilus holds a bowl-shaped ventral pharyngeal apparatus, lacking a muscular bulbus, but showing an exclusive composition of glands and muscles. The nervous system shows no signs of segmentation and includes two supra-oesophageal ganglia in addition to specialized nerves inner- vating the ventral ciliophores. The total lack of annelid synapomorphies and larval features except for minute size, contraindicates with a progenetic origin for Diurodrilus. It is therefore here rejected that Diurodrilus occupies a derived position within Annelida.

Presenter (*) 86 Oral Abstracts

Polychaetes consumption by the marine fishes in the Eastern Bering Sea and Gulf of Alaska

Mei-Sun Yang*, Geoff Lang, Angie Greig & Kerim Aydin

Alaska Fisheries Science Center, NOAA, 7600 Sand Point Way NE, Seattle, WA 98105, USA

This study reviews the consumption of polychaetes by marine fishes in the eastern Bering Sea and Gulf of Alaska. Data from the years 1982 to 2006 in the eastern Bering Sea and data from 1984 to 2005 in the Gulf of Alaska are used.

The main fish predators of polychaetes included Alaska plaice (Pleuronectes quadrituberculatus), northern rock sole (Lepidopsetta polyxystra), Yellowfin sole (Pleuronectes asper), Dover sole (Microstomus pacificus), rex sole (Errex zachirus) and flathead sole (Hippoglossoides elassodon). The geographic distributions of polychaetes in the stomach contents of different predators were described.

Indices of polychaetes abundance (expressed as percentage of total stomach contents weight) by sub-region were estimated to show the relative abundance of polychaetes consumed each year by ground fish in both the eastern Bering Sea and Gulf of Alaska. Polychaetes abundance ranged between 71% of Alaska place stomach contents and 1% of flathead sole stomach contents in the eastern Bering Sea. In the Gulf of Alaska, polychaetes abundance ranged from 1% of flathead sole stomach contents to 57% of sole stomach contents.

Estimates of the total amount of polychaetes consumed by the ground fish population during each summer feeding season of each year ranged from 93,100 metric tons (t) in 1999 and 27, 700 t in 1990 for the Gulf of Alaska. In the eastern Bering Sea, the estimate was between 2,632,000 t in 1994 and 914,400 t in 1985.

Presenter (*) 87 Oral Abstracts

Phylogeny of Eunicidae (Annelida) based on 16S, COI and 18S sequences

Joana Zanol1*, Kenneth M. Halanych2 & Kristian Fauchald3

1 George Washington University, 2023 G St. NW, Suite 340, Washington, DC 20052, USA 2 101 Life Sciences Building, Dept. of Biological Sciences, Auburn University, Auburn, AL 36849, USA 3 Department of Invertebrate Zoology, NMNH, MRC 0163, Smithsonian Institution, P.O. Box 37012, Washington, DC20013-7012, USA

Eunicid polychaetes (10genera/~326spp.) have worldwide distribution and include many active large species. Some of these are important in fishing bait industries or as cultural food. Despite the importance of the group, the monophyly of Eunicidae is uncertain. Definitive synapomorphies are lacking and exclusively plesiomorphic and homoplastic morphological characters group its species. Furthermore many molecular analyses do not support its monophyly. The type genus, Eunice, is paraphyletic in a morphological analysis and the main diagnostic characters of other genera vary during ontogeny and regeneration. Here we tested the monophyly of Eunicidae and its genera using molecular data. 16S, COI and 18S sequences (~4,100bp) were examined for 53 Eunicidae species, representing the six most species-rich genera. Eight species of Onuphidae were used to assess their position relative to Eunicidae and species of other Eunicida families, Amphinomidae and Glyceridae were used as outgroups. All sequences were combined in a single matrix and analyzed under parsimony, maximum likelihood and Bayesian inference. A poorly supported monophyletic Eunicidae was sister to Onuphidae in all analyses. Eunice paraphyly was recovered, with species in at least three clades, however only two were consistent in all analyses. The basal clade within the family groups Eunice species with yellow bi- and tridentate subacicular hooks. The second clade groups Nicidion-like species and two Marphysa-like species, making Marphysa paraphyletic. The placement of Eunice roussaei- the species most similar to the type species of Eunice included in the analyses- is uncertain, making it impossible to delimit Eunice sensu stricto. Marphysa sensu stricto, including Marphysa sanguinea, forms a sister clade to the Nicidion clade; Lysidice is also para- phyletic, with Nematonereis nested within it; Palola is monophyletic, sister to the clade (Euniphysa (Lysidice, Nematonereis)).

Presenter (*) 88 Oral Abstracts

Investigations on the morphology and anatomy of Travisia forbesii Johnston, 1840 (Annelida, Polychaeta)

Anna E. Zhadan*, A.B. Tzetlin & S.S. Vodopianov

Moscow State University, Biological Faculty, Leninskie Gory, 1-12, Moscow 119992, Russia

Travisia traditionally referred to Opheliidae was transferred to Scalibregmatidae on basis of molec- ular data (Bleidorn et al, 2003; Hall at al, 2004; Persson, Pleijel, 2005). But recent study (Rousset et al, 2007) provides strong support for the monophyly of the traditional Opheliidae with Travisia included. At the same time, anatomy of Travisia is still poorly known.The anatomy and morpholo- gy of Travisia forbesii Johnston, 1840 was studied using SEM, histological methods and light microscopy with special emphasis on the integument, intestinal tract, musculature and circulatory system. The results show that: All chaetae are covered by secondary filaments very similar with the same in scalibregmatids. Nuchal organs are small ciliated invaginations situated on lateral sides of prostomium. Epithelium is pseudo-stratified: small basal parts of cells contain nuclei whereas prominent distal parts are filled with dark granules, probably bacteria. Between two layers homoge- nous fibrous lamella is situated. On the outside integument consists of large polygonal cells. Structure of epithelium differs from epidermis in both scalibregmatids and opheliids. Body cavity divided by four septae in anterior part and several septae in posterior. Segmental organs are four metanephridia with nephropores on VI or IX setigers. Their funnels are closely associated with seg- mental blood vessels. Intestinal tract includes eversible ciliated soft axial pharynx, oesophagus with two voluminous sac-like glands, looped and strongly folded gut. Ring muscles cover the ventral nerve cord. Longitudinal muscles arranged in one dorsolateral and two ventral strands. Numerous oblique muscles extend from the ventral nerve cord to body wall beneath parapodia. Circulatory system represented by a peri-intestinal blood sinus, anterior dorsal vessel (heart) without heart body and segmental vessels with blind projections in anterior segments. Our study does not allow making unambiguous decision on position of Travisia within Opheliidae or Scalibregmatidae.

Presenter (*) 89 Poster Abstracts

Some unusual genera of Syllidae (Phyllodocida: Annelida)

Aguado, M. Teresa* & Guillermo San Martin

Universidad Autónoma de Madrid, Madrid, Spain

Several genera have been assigned to the family Syllidae because of the presence of a clear and well defined proventricle. However, their relationships with the rest of syllids were difficult to elu- cidate since they show a combination of characters which does not fit the diagnosis of any of the traditionally recognized subfamilies. Given that most of these taxa were poorly known, their type species have been examined in order to re-describe them, when necessary, and to discuss their pos- sible evolutionary relationships. New diagnoses are provided for the following genera: Anguillosyllis Day, 1963, Clavisyllis Knox, 1957, Lamellisyllis Day, 1960 and Nuchalosyllis Rullier & Amoreux, 1979. Brachysyllis Imajima & Hartman, 1964, previously synonymized with Dioplosyllis Gidholm, 1962, is considered a valid taxon. Three more genera are considered non- valid taxa: Braniella Hartman, 1964, synonym of Anguillosyllis; Alluaudella Gravier, 1905, syn- onym of Odontosyllis Claparède, 1863 and Exogonella Hartmann, 1961, synonym of Paraexogone Mesnil & Caullery, 1918. Exogonoides Day, 1963 is considered nomina dubia since its relationship with syllids could not be established. Other recently described genera, also difficult to assign to any subfamily, are included in the discussion.

Presenter (*) 90 Poster Abstracts

Paragnath atlas for nereidid polychaetes (Polychaeta, Nereididae)

Bakken, Torkild,1* Christopher J. Glasby2 & Robin S. Wilson3

1 Norwegian University of Science and Technology, Trondheim, Norway 2 Museum & Art Gallery of the Northern Territory, Darwin, Australia 3 Museum Victoria, Melbourne, Australia

Scleroprotein paragnaths on the pharynx have for 150 years been used as a principle system of char- acters to distinguish species and other taxonomic ranks in the polychaete family Nereididae. Recent studies have shown that phylogenetic relationships based solely on paragnaths are in conflict with relationships inferred from other characters. Furthermore, recent species descriptions continue to increase the range of known paragnath forms. No comprehensive overview of these important mor- phological characters has ever been published. It is now timely to provide such a review, which will enable more accurate character descriptions and encourage more consistent observation by use of a standardized terminology in species descriptions. Detailed illustrated descriptions and definitions of all known paragnath types are presented and compared. A classification scheme and terminology is introduced to aid description of paragnath types. In a phylogenetic sense, more detailed character knowledge is especially important in relation to recognizing homologous features. Explicit hypothe- ses are proposed for homology between different paragnaths types, and between scleroprotein paragnaths and pharyngeal soft papillae in Nereididae.

Presenter (*) 91 Poster Abstracts

Distribution of Idanthyrus cretus (Sabellaridae:Polychaeta) in the tropical eastern Pacific and application of PCR-RAPD’s tools for population analysis

Barrios, L.M., S. J. Chambers,1* N. Ismail, J.M. Mair & H. Guzman

1 National Museums of Scotland, Edinburgh, Scotland

Sabellariid polychaetes, commonly known as honeycomb worms, can form large reef-like aggrega- tions in many parts of the world. One species, Idanthyrsus cretus Chamberlain, 1919, has recently been found in several localities during surveys of the Las Perlas Archipelago, in the Tropical East Pacific (TEP) of Panama. Large sabellarid colonies were found only in the southwestern area of the archipelago in areas of high exposure. The distribution patterns were examined and mapped with the aid of GIS. Large reefs of this species have not been recorded elsewhere for the TEP. Preliminary PCR-RAPD analysis of 12 stations (4 replicates per station) show that the reef corre- sponds to more than one colonization event. The TEP current patterns show that the populations in Las Perlas Archipelago probably originated from further south in Pacific America (Colombia or Ecuador). To confirm the reef origin, it would be necessary to analyze samples from those countries using the same techniques.

Presenter (*) 92 Poster Abstracts

A comparison of some Salmacina populations (Serpulidae) from different biogeographic regions

Ben-Eliahu, Nechama1* & Harry A. ten Hove2

1 Hebrew University of Jerusalem, Jerusalem, Israel 2 Zoologisch Museum Amsterdam, Amsterdam, Netherlands

When Salmacina dysteri, type locality Carmarthen Bay, Wales, was reported by F.A. Potts (1927) from the Suez Canal and Gulf of Suez, he invoked the frequently used, controversial term “cos- mopolitan.” Salmacina dysteri is presently mentioned among the alien ship-dispersed invasive species in Hawaii. The possible dispersal by ship complicates analysis of the biogeography of this genus. In order to evaluate the distribution of Salmacina dysteri, Salmacina populations from dif- ferent biogeographic regions including the Mediterranean, Suez Canal and Gulf of Aqaba (Red Sea), are being compared with Salmacina dysteri from the type locality. Easily studied is the pres- ence or absence of prostomial ocelli. Clearly visible in live Salmacina specimens from the Gulf of Aqaba, residues were still observed in alcohol-preserved specimens five years later, though not in specimens collected 30 years earlier. In preserved material, the character, “presence or absence of prostomial ocelli,” should not be considered as robust. Presumably much more robust characters are the structure of the chaetae and the uncini. In view of their minute size, proper analysis of their structure dictates resorting to the Scanning Electron Microscope. As this was not widely used until some years ago, it follows that earlier records must be re-examined. Preliminary results show con- siderable variability in structure of fin-and-blade collar chaetae even within a single fascicle. The variability in characters within the different populations will be documented. Further complicating interpretation of the results is variability within asexually reproducing taxa such as Salmacina. Ultimately material from these localities should be compared using genetic techniques.

Presenter (*) 93 Poster Abstracts

A new genus, species and records of polynoids from Southern California whale and wood- falls, including relationships to hydrothermal vent species

Benn, A., K. Kemp,1* T.G. Dahlgren2, C.R. Smith3, A. Baco-Taylor & A.G. Glover1

1 The Natural History Museum, London, UK 2 Göteborg University, Göteborg, Sweden 3 University of Hawai’i at Manoa, Honolulu, Hawai’i

Polychaetes within the family Polynoidae are abundant and diverse at deep-sea reducing habitats such as hydrothermal vents, cold seeps, and large organic falls. Whilst the vent fauna is compara- tively well described, few taxonomic studies have been undertaken of material from whale or wood- falls, which are now known to be commonly encountered reducing habitats on the deep-sea floor. Here we report on the discovery of a new genus and species of polynoid polychaete from a whale fall in the Santa Catalina Basin, California. The specimens were found commensal with hydroids attached to whale bones and are thought to represent a new genus of polynoid. We discuss the pos- sibility of whale and wood-falls acting as stepping-stones for the dispersal of polynoids over both ecological and evolutionary time.

Presenter (*) 94 Poster Abstracts

Tube decoration may not be cryptic for Diopatra cuprea (Polychaeta: Onuphidae)

Berke, Sarah* & Sarah Woodin

University of South Carolina, Columbia, South Carolina, USA

Diopatra cuprea Bosc is a conspicuous tube-dwelling polychaete that dominates sedimentary sys- tems from Cape Cod, Massachusetts, USA, through Brazil. Other Diopatra species are similarly dominant in tropical and temperate sediments worldwide. Like many Diopatra species, D. cuprea’s deep vertical tube terminates in a tube-cap that extends 2–4 cm above the sediment surface; this tube-cap is characteristically decorated with debris including shell hash and algal or plant frag- ments. Several adaptive functions have been suggested for tube-cap decoration. We tested the hypothesis that decoration provides crypsis. A series of field experiments quantified predation-relat- ed damage done to tube-caps that were (1) devoid of decoration, (2) decorated with algae, and (3) decorated with shell fragments. If decoration provides crypsis, then undecorated tube-caps should experience more damage than decorated tube-caps; this pattern was not observed. Decoration may still reduce predation rates by means other than crypsis, but these results strongly suggest that tube decoration does not interfere with predator recognition of D. cuprea tube-caps and that crypsis is consequently not important in this system.

Presenter (*) 95 Poster Abstracts

Capitella capitata (Fabricius) from West Greenland: redescribed and compared with the Grassle culture of Capitella sp. I

Blake, James A.,1* Judith P. Grassle2 & Kevin J. Eckelbarger3

1 ENSR Marine & Coastal Center, Woods Hole, Massachusetts, USA 2 Rutgers University, New Brunswick, New Jersey, USA 3 University of Maine, Walpole, Maine, USA

Capitella capitata was originally described by Otto Fabricius in 1782 as Lumbricus capitatus from the SW coast of Greenland, believed to be near the town of Paamiut, formerly Frederickshaab. There is no type material, but collections of C. capitata from along the W and SW coasts of Greenland were reported by Wesenberg-Lund (1950) and Curtis (1977). These collections are in the Zoological Museum, University of Copenhagen. A representative collection was made available to the first author by Dr. Eibye-Jacobsen and provides the basis for a redescription and reconsideration of the type-species of Capitella. A redescription of C. capitata is necessary because numerous genetically distinct, yet morphologically similar species of Capitella are now known. Biological studies have demonstrated differences in chromosomes, gametogenesis, morphology of larvae and type of larval development, together with limited adult morphological considerations. Here, we present a redescription of the adult morphology of C. capitata from W Greenland together with lim- ited observations on reproduction and brooding. At the same time, we present comparative obser- vations on Capitella sp. I and provide a name to replace the provisional species designation. Morphology that differs between C. capitata and C. sp. I includes the form of the prostomium, size and shape of the thoracic region, degree of modification of setigers 8–9, setal details, and methyl green staining reactions. The type-species appears to be hermaphroditic because specimens with genital spines have been found with eggs in the coelom; others were found with eggs and embryos in their tubes. [Supported by the National Science Foundation under Grant No. DEB-0118693 (PEET) to James A. Blake, University of Massachusetts, Boston]

Presenter (*) 96 Poster Abstracts

Polychaete Diversity in Deep-Sea Infaunal Assemblages: Western North Atlantic, Eastern Pacific, and the Weddell and Scotia Seas, Antarctica

Blake, James A.1*, Stacy A. Doner1, Nancy J. Maciolek1 & Bhavani E. Naranaswamy2

1 ENSR Marine & Coastal Center, Woods Hole, Massachusetts, USA 2 Scottish Association for Marine Science, Dunstaffnage Marine Laboratory, Oban, UK

Extensive investigations of benthic infauna collected from box core and multicore samples from continental slope and abyssal habitats have produced a harvest of new taxa previously unsuspected that add significantly to global biodiversity estimates. Collections of benthic infauna from continen- tal slope and abyssal depths of the Western North Atlantic, Eastern Pacific, and more recently in the Weddell and Scotia Seas of Antarctica reveals consistent global patterns in deep-sea polychaete bio- diversity. A total of 692 species of polychaetes were collected from 554 benthic box cores from the U.S. Atlantic continental slope and rise as part of the ACSAR program (1983–1986) in depths of 500–3500 m; of these, 290 species or 42% were believed to be new to science. During baseline studies off northern California (1990–1991) intended to identify a deep-water dredged-material dis- posal site (500–3000 m), 368 species of polychaetes were identified from 64 box core samples of which 162 species or 42% were new to science. A follow-on program to monitor dredged material disposal was conducted from 1996 to 2004 from which 345 species of polychaetes were collected from a relatively small geographic area (2400–3200, and 3600–3800 m). Of these polychaetes, 220 species or 64% were new to science. Samples from ANDEEP II and III (1000–6000 m) in Antarctica yielded a total of 170 species of polychaetes, of which 108 species or 64% were new to science. Despite the great geographic separation encompassed in these programs, several consistent trends are apparent. The families Paraonidae and Cirratulidae are by far the most speciose in all three areas with perhaps hundreds of new taxa; the Spionidae are typically also among these domi- nant families but are replaced to some extent by Sabellidae in Antarctica. The dominance of Paraonidae and Cirratulidae in deep-sea sediments is consistent in all three areas and reflects consis- tent global biodiversity patterns in deep-sea benthic infaunal communities from deep bathyal and abyssal habitats. [Supported by the National Science Foundation under Polar Division Grant No. OPP-0086655 and Grant No. DEB-0118693 (PEET) to James A. Blake, University of Massachusetts, Boston]

Presenter (*) 97 Poster Abstracts

Glyceriformia Fauchald, 1977 (Annelida: Polychaeta) from the SW Atlantic Shelf, between 30º and 45º S

Böggemann, Markus1* & José María (Lobo) Orensanz2

1 University of Osnabrück, Osnabrück, Germany 2 Centro Nacional Patagonico (CENPAT), Chubut, Argentina

We document the presence of 16 species of Glyceriformia: Glyceridae: Glycera americana, G. capi- tata, G. lapidum, G. oxycephala, G. sp. A, Hemipodia californiensis, H. pustatula, H. simplex and Goniadidae: Glycinde armata, G. multidens, G. sp. A, Goniada crudelis, G. echinulata, G. gigantea, G. virgini, G. vorax) in the transitional zone between warm and cold temperate domains of the southwestern Atlantic (30º–45º S). This more than doubles the number of species known to occur in the region and upgrades previous records, many of them unreliable. Ten of the species are primarily associated with warm-temperate, and only two with cold or cold-temperate waters; the remaining four are eclectically distributed in temperate waters. Twelve of the species are present in the north- western and southwestern Atlantic, sometimes with an apparent distributional gap in the tropics, consistently with what has been observed in other groups of marine organisms.

Presenter (*) 98 Poster Abstracts

Polychaeta diversity in the continental shelf off the Orinoco`s River Delta, Venezuela

Bone, David*, Carmen Rodriguez & Iliana Chollet

Universidad Simón Bolívar, Caracas Venezuela

In recent years Venezuela has undergone off-shore gas exploration activities on the continental shelf off the Orinoco River delta. This effort has allowed multidisciplinary baseline studies of a region largely unexplored, characterized by a heavy influence of the Orinoco’s continental waters (0.25 to 36.92‰). We report on polychaetes associated with these bottoms along a depth gradient, which was divided into zones: from 0 to 60 m (1), from 60 to 200 m (2), and from 200 to 1500 m (3). A total of 2,452 individuals were collected, belonging to 43 families, showing a high biodiversity, with Spionidae, Pilargidae and Paraonidae as the most important ones; the rest represented less than 7%. At a species level, we have identified 82 species: 18 species in zone 1, 69 in zone 2, and 21 in zone 3. The most important ones in zone 1 are: Cossura delta, Dipolydora socialis, Prionospio delta and Scoletoma verrilli; Spiophanes duplex, P. delta, Monticellina annulosus, Terebellides stroemi and Aglaophamus verrilli in zone 2; and Levinsenia gracilis, Cirrophorus lyra, S. duplex, P. delta and Tharyx acutus in zone 3. As a general pattern we observed that the average density values are low compared to other areas in Venezuela, ranging from 15.62 ind/m2 in zone 1 to 36.34 ind/m2 in zone 3, but species richness is high, which are characteristic tendencies of deep water benthic communities. No significant correlations were found with depth gradient or other environmental variables, except salinity (p<0,02), suggesting a clear influence of the Orinoco River in the shallow continental shelf zone.

Presenter (*) 99 Poster Abstracts

A new species of Poecilochaetus (Polychaeta, Poecilochaetidae) from coastal waters off Southern California, USA

Brantley, Cheryl A.*

County Sanitation Districts of Los Angeles County, Carson, California, USA

A new species of Poecilochaetus (Polychaeta, Poecilochaetidae) is described from coastal waters off southern California. The material was collected as part of the benthic infaunal survey work required under the Clean Water Act’s NPDES permit program and conducted by the County Sanitation Districts of Los Angeles as part of its ocean monitoring program. The distinct characters of this new species were first noted three decades ago but a formal description was never published. It has been reported frequently in survey data under a provisional name of Poecilochaetus sp. A. The new species is unique in the number of branchial filaments and the location of these filaments along the body. This new species also has interramal cirri on the branchiate setigers, a character often undescribed by previous authors of Poecilochaetus. Several specimens of this new species have been collected throughout the Southern California Bight during regional surveys in 1994, 1998 and 2003. This new species is compared to other branchiate species in the genus.

Presenter (*) 100 Poster Abstracts

Deep-sea polychaetes associated with coral banks of Campos Basin: first records for the Brazilian continental margin, Southwest Atlantic

Brasil, Ana Claudia dos Santos*, P.C. Paiva, G. H. Cavalcanti & M. P. Curbelo Fernandez

Universidade Federal Fluminense, Rio de Janeiro, Brazil

Deep-sea ecosystems in the SW Atlantic are poorly known. However, in recent years some Brazilian initiatives have improved the knowledge of the area. The Campos Basin Deep-Sea Coral Assessment Project is one of these initiatives, conducted by the Brazilian Energy Company- PETROBRAS. The main aim of this project has been to assess coral banks and associated fauna in the southern part of Campos Basin using images recorded with remotely operated vehicles and physical samples. The surveyed area is located in the northern part of Rio de Janeiro State, off Macaé City (23º30’S). Images and samples were obtained from coral banks in depths ranging from 700 to 1100 m. No images of polychaetes were captured in 48 hours of images, probably due to the size of the organisms. The polychaete samples consisted of four individuals of Eunice cf. norvegica (Linnaeus, 1767) (Eunicidae) and two individuals of the polynoid Lagisca floecosa unidentata Augener, 1906. Several authors have confirmed the beneficial relationship between E. norvegica and the deep-water reef-forming coral Lophelia pertusa, but the eunicid in this study did not match completely with this description. Both Polynoidae were found inside the poriferan Euplectella sp.

Presenter (*) 101 Poster Abstracts

Phylogeny of Magelonidae Cunningham & Ramage, 1888 (Polychaeta: Spionida) based on external morphology

Brasil, Ana Claudia dos Santos,1* W. Boeger & Paulo C. Lana2

1 Universidade Federal Fluminense, Rio de Janeiro, Brazil 2 Universidade Federal do Paraná, Centro de Estudos do Mar, Pontal do Sul, Brazil

The present study presents a phylogenetic hypothesis of relationships among members of the Magelonidae, based on 61 external morphological characters, including several new features. Two phylogenetic analyses were performed. The first was based on direct examinations of members of 53 species, and the second included all 76 valid species, based on additional data from the litera- ture. All characters were treated as unordered and weighted equally. Matrices were analyzed using PAUP 4 with heuristic searches, random addition sequences with 1000 replicates, and tree bisection- reconnection. The first analysis yielded nine minimum-length trees, each 288 steps. The monophyly of Magelonidae is supported by three characters: the shovel-shaped prostomium, palps with papil- lae, and palps inserted ventrally. Eight major clades in the strict consensus tree are apparent, though the analysis suggests that Meredithia and Octomagelona are paraphyletic. The complexity of the second analysis generated a memory overflow. Nevertheless, Magelonidae remains monophyletic, supported by the same characters. All results suggest that position and shape of notopodial and neu- ropodial lateral lamellae, and the differentiation of the thorax are the features that better split species within the family. The present study suggests that thorax differentiation, and positions and shapes of the lateral lamellae need to be carefully described for future studies on the evolution of the group.

Presenter (*) 102 Poster Abstracts

Ultrastructure of nuchal organs and larval photoreceptors in Cirratulidae and its phylogenet- ic significance

Brauer, Saskia* & Harald Hausen

Free University Berlin, Berlin, Germany

The composition and systematic position of Cirratulidae is discussed. In order to test the traditional view of a close relationship between cirratulids and spiomorphic polychaetes, we investigated the ultrastructure of nuchal organs and larval light-sensitive organs in Cirriformia tentaculata and Aphelochaeta marioni. The nuchal organs show a common structure as seen in most polychaetes. However, the organs lack the paving-stone-like cover by inflated supportive cellular microvilli, which is characteristic for spiomorph polychaetes. Cirratulid microvilli are slender and resemble those of adjacent epidermis cells as often seen in many polychaete taxa. The planktonic larvae of C. tentaculata possess only one pair of light-sensitive organs with a very peculiar ultrastructure. This organ is composed of two receptor cells and one pigment cell. The cells bear both microvilli and a long, slightly branching cilium. The microvilli enter a small pigment cup, which is not sealed from the subcuticular extracellular space by any cell contacts. The organs differ considerably from the typical few-celled larval rhabdomeric ocelli of other polychaetes in receptor cell orientation, branching pattern of the microvilli and the open pigment cup. The receptor cilia do not enter the pigment cup, but run directly underneath the cuticle, as compared to the presumably light-sensitive organs of larvae of Spionidae and relatives, where the cilia enter a large, sealed cavity formed by an unpigmented receptor cell. A close relationship between Cirratulidae and spiomorphic polychaetes is thus not supported neither by nuchal organ nor by larval light sensitive organ structure.

Presenter (*) 103 Poster Abstracts

A new species of the genus Diopatra Audouin & Milne-Edwards, 1833 (Polychaeta, Onuphidae) from Belize

Budaeva, Nataliay1* & Kristian Fauchald2

1 Russian Academy of Sciences, Moscow, Russia 2 Smithsonian Institution, Washington, D.C., USA

More than 80 specimens of a new onuphid species of the genus Diopatra Audouin & Milne- Edwards, 1833 have been collected at the intertidal zone in the vicinity of Smithsonian field marine station (Carrie Bow Cay, Belize) from 1976 until 2006. The genus Diopatra includes more than 40 valid species but of these only four, D. dubia Day, 1960, D. papillata, Fauchald, 1968, D. angolen- sis, Kirkegaard, 1988, and D. sp. nov have lateral projections on the ceratophores. Since most Diopatra species have a wide range of intraspecific variability, the type specimens of D. dubia and D. angolensis and the original description of D. papillata were carefully analyzed in order to com- pare described species with the new one. The new species can be characterized by a combination of features such as the presence of large projections on both palpophores and antennophores, bidentate pseudocompound falcigers with moderately pointed hoods in the first five setigers, eyespots on prostomium, nuchal organs almost forming a circle and very large sensorial buds on antennostyles and frontal lips. Five 28-setiger juveniles were found inside the parental tube of one specimen. Formal description of adults and juveniles with comments on patterns of anterior region regenera- tion, drawings and SEM photographs are provided.

Presenter (*) 104 Poster Abstracts

Spatial changes of continental shelf zoobenthic communities in the Gulf of Noto (eastern Sicily, Ionian Sea), with special attention to the polychaete fauna

Cantone, Grazia* & Daniela Iraci Sareri

Università di Catania, Cantania, Italy

Few studies have investigated the macrofaunal assemblages of the southernmost part of Sicily. The present study investigates the biocenoses of the continental shelf of the Gulf of Noto (Ionian Sea) from 3 to 200 m. Polychaetes were the dominant taxon, followed by molluscs and crustaceans. Polychaete families and functional groups differed between the various habitats that were investi- gated and were correlated with bathymetrical and small-scale physical and environmental factors. A similarity analysis shows that differences in polychaete assemblages and macrofaunal density did differ greatly in homogenous subareas differently influenced by anthropomorphic activities. Environmental factors are thought to be responsible for the large variation in polychaete assemblage structure within habitats. The present study builds on earlier work in the region and provides pur- pose-collected data which will enable small and broad-scale comparison of benthic biodiversity of the eastern coast of Sicily.

Presenter (*) 105 Poster Abstracts

Comparative internal structure of dorsal lips and radiolar appendages in Sabellinae (Sabellidae, Polychaeta) and phylogenetic implications.

Capa, Maria,1* Maíra C. Silva Rossi2 & João M. de Matos Nogueira2

1 Australian Museum, Sydney, Australia 2 Universidade de São Paulo, São Paulo, Brazil

Dorsal lips in sabellids are paired, erect, ciliated structures, located dorsally to the mouth, within the branchial lobes. Fabricinae and some Sabellinae have short and rounded dorsal lips or narrow ridges but most sabellins have long, distally tapering dorsal lips due to the presence of an appendage and paired lateral lamellae on each lip. Dorsal radiolar appendages are homologous to the radioles as both structures share the presence of a main longitudinal blood vessel, two longitudinal nerves and, in some taxa, a longitudinal row of vacuolated cells (chondrocytes), surrounded by a hyaline carti- lage matrix. There have been several studies dealing with the internal structure of the dorsal lips and dorsal radiolar appendages, including implications in the phylogeny of the family, but the pres- ent study is more comprehensive as more taxa are added to the data set and other interpretations of the observations are given and discussed in comparison with previous studies. Dorsal lips and radio- lar appendages of several species and genera of sabellins were dehydratated, sectioned and stained with Mallory’s Triple Stain for the study of the presence and arrangement of the different tissues within these structures. For the phylogenetic analysis (maximum parsimony), species of Sabellinae constituted the ingroup and Fabricinae were outgroups. Results are discussed and compared with previous phylogenetic hypotheses.

Presenter (*) 106 Poster Abstracts

A new genus of sabellid polychaete (Polychaeta: Sabellidae)

Cappellani Silva Rossi,Maíra1, João Miguel de Matos Nogueira1* & Kirk Fitzhugh2

1 Universidade de São Paulo, São Paulo, Brazil 2 Natural History Museum of Los Angeles County, Los Angeles, California, USA

Specimens belonging to a new genus of sabellid polychaete were collected from algae, sponges, ascidians, and similar substrates on a rocky shore along São Sebastião, State of São Paulo, Brazil. Specimens were examined alive using stereomicroscopy, relaxed in menthol solution, then fixed in 4% sea-water formalin, then washed and preserved in 70% ethanol. Specimens were subsequently studied using light microscopy and SEM. In life, members of this new genus have small interramal eyespots, as well as several characters common to Bispira Kroyer, 1856, such as a short palmate membrane, presence of radiolar flanges, thoracic neuropodia bearing companion chaetae, and abdominal notochaetae in a partially spiralled arrangement. Specimens differ from members of Bispira in having 4–5 thoracic chaetigers; small, unpaired, irregularly-spaced radiolar eye spots, and different morphologies for companion chaetae and inferior thoracic notochaetae. However, the spec- imens lost pigmentation, including the interramal eyespots, shortly after preservation, giving an appearance very similar to that of Perkinsiana minuta (Treadwell, 1941), also described from São Sebastião. Members of P. minuta have a similar body length, number of thoracic chaetigers, collar morphology, chaetae, and uncini. According to the redescription by Knight-Jones (1983), P. minuta, known only from the holotype, has small brown spots on the radioles, which correspond to the radi- olar eye spots. Therefore, we transfer P. minuta to the new genus herein described.

Presenter (*) 107 Poster Abstracts

Four new species of sabellid polychaetes (Polychaeta: Sabellidae) from rocky shores off the State of São Paulo, southeastern Brazil

Cappellani Silva Rossi, Maíra & João Miguel de Matos Nogueira*

Universidade de São Paulo, São Paulo, Brazil

In a study on polychaetes living at the intertidal zone on rocky shores along the State of São Paulo, new species and new occurrences of sabellids for Brazilian waters were found. We herein describe four new species, one of which, a fabriciine belonging to the genus Fabriciola Friedrich, 1939, is the first record for this genus in Brazil. All other species are sabellins, belonging to the genera Amphicorina Quatrefages, 1850, Notaulax Tauber, 1879, and Pseudopotamilla Bush, 1905. Material was collected by scraping rocks to extract small tufts of algae, sponges, ascidians, and similar sub- strates. Material was examined alive under a stereomicroscope; polychaetes were sorted, relaxed in menthol solution, fixed in 4% formaldehyde, then washed and stored in 70% ethanol. The speci- mens were studied under stereomicroscope, light microscope, and SEM. Fabriciola sp. nov. is simi- lar to F. tonerella Banse, 1959 in body length, presence of red ocelli and morphology of chaetae. However, the original description of that species does not provide information on the morphology of the uncini and, considering its type locality is in the Red Sea, it is unlikely the same species occurs in Brazil. Amphicorina sp. n. has 3 pairs of radioles and 6–10 abdominal chaetigers. It is close to A. bichaeta Capa and López, 2004, but differs in the morphology of the notochaetae and abdominal uncini. Notaulax sp. n. has collar chaetae arranged in two rows, dark red to purple radio- lar crown and few eyespots, arranged in irregular rows. It differs from all congeners in having collar chaetae arranged in two rows. Pseudopotamilla sp. n. has a fan-shaped radiolar crown, with radioles progressively longer ventralwards, 1–3 red to orange compound eyes per radiole, on the dorsal half of crown, and a low collar, not covering anterior peristomial ring dorsally and laterally. The shape of the collar distinguishes this species from all congeners.

Presenter (*) 108 Poster Abstracts

Deep and long reductions of the polychaeta fauna coincide with the cold phase of the El Niño: southern oscillation event at the bottom of Bahía de Concepción, Chile

Carrasco, Franklin D.* & Rodrigo A. Moreno

Universidad de Concepción, Concepción, Chile

Deep and long reductions of the numerical abundance of the Bahía de Concepción sublittoral macroinfauna (>0.5 mm), have been observed during monitoring cruises conducted in the area from March 1988 to January 1991. The samples were collected at two fixed stations, one nearby to Talcahuano’s Port (7 m depth) and other in the center of the bay (22 m depth). Samples were col- lected bimonthly using a 0.1-m2 Smith-McIntyre benthic grab, with three replicates at each station. The benthic macrofauna was clearly dominated by polychaete worms, both in the numbers (> 97%) and biomass (> 96%). The numerical abundance was dominated by the polychaetes Carazziella car- rascoi (36%), Rhynchospio glutaea (26%) and Capitella capitata (22%) at Talcahuano bottoms. At the bottom of the center of the bay, the polychaetes Paraprionospio pinnata (77%), Cossura chilen- sis (13%) and Aricidea pigmentata (4%) were the most abundant. In the analysis of the numerical abundance dynamics, wide or extensive reductions of the polychaete numbers in both localities were observed from March 1989 to May 1990. In general these remarkable reductions in abundance were coincident with the cold phase of the El Niño-Southern Oscillation (ENSO), known “La Niña,” event, which developed and reached its highest expression between June 1988 and October 1989. The most impacted forms were in Talcahuano (C. carrascoi and R. glutaea) and, very remarkably, P. pinnata and also A. pigmentata at the bottom of the center of the bay.

Presenter (*) 109 Poster Abstracts

Abyssal bitentaculate cirratulids: unifying the species concept

Chambers, Susan1*, Stacy Doner2, Gordon Paterson3, Eulogio Soto Oyarzun4 & James A. Blake2

1 National Museums of Scotland, Edinburgh, Scotland 2 ENSR Marine & Coastal Center, Woods Hole, Massachusetts, USA 3The Natural History Museum, London, UK 4 University of Valparaiso, Valparaiso, Chile

In January 2007, the Abyssal Polychaete Intercalibration Project (APIP) workshop was held at the Natural History Museum (NHM) in London. The aim of this workshop was to discuss strategies to overcome the “taxonomic impediment” in the study of abyssal (>3000 m) polychaetes as well as to undertake trial taxonomic synthesis studies. Taxonomists and abyssal samples from multiple geo- graphic regions were brought together in order to produce guidelines for a future, larger study. The Cirratulidae are highly diverse in abyssal sediments with large numbers of undescribed species, consequently they were one of the families chosen for special attention. The aim of this presentation is to illustrate what was learnt during the APIP workshop as well as to develop plans for dealing with large numbers of undescribed species. Bitentaculate cirratulid characters required for compari- son of widely separated abyssal locations were compiled from data collected from the Pacific, Atlantic and Antarctic abyssal plains and basins. The computer program DELTA (DEscription Language for TAxonomy) was selected as a means of compiling morphological data. A set of mor- phological characters and states were established and entered into DELTA together with illustrations of these to ensure a common language among the taxonomists involved. Once this database is popu- lated, specimens from various projects and localities will be compared in order to determine simi- larities and differences.

Presenter (*) 110 Poster Abstracts

An unexpected reef-building worm in Mar del Plata, Argentina (SW Atlantic)

Chiaradia, N., C. Marchesi, D. Azone, A. San Martín, D. Giberto, C. Bremec & R. Elías*

Universidad Nacional de Mar del Plata, Buenos Aires, Argentina

This contribution reports the presence of coastal reefs built by the sabellariid Sabellaria wilsoni Lana & Gruet, 1989, in Mar del Plata (38º S). Benthic studies developed in the rocky littoral of the study area do not report the presence of polychaete reefs. The species is known from different local- ities in the SW Atlantic: Paraná State in Brazil (25º30’ S), Mar Chiquita (37º S) and Monte Hermoso (39º S) in Argentina, and probably French Guiana, between 6 and 16.5 m depth. All records correspond to shallow depths in coastal environments; it was never recorded in shelf areas intensively sampled in the Argentine Biogeographical Province. S. wilsoni reefs are composed of sandy straight tubes and vary between 20–30 cm and nearly 100 cm in diameter; they are located in different pools at the upper rocky intertidal zone, largely extended in the study area. We present information about size distribution patterns of the population and the composition of the associated fauna from samples obtained in June and October 2006 during low tides. The presence and reef- building capacity of the species, not recorded previously, in an intertidal exposed zone strongly influenced by tides indicates its adaptation to highly variable environments.

Presenter (*) 111 Poster Abstracts

Redescription of Cirratulus dollfusi Fauvel, with proposal of a new genus and discussion of the affinities of the species

Melih Ertan Çinar1 & Mary E. Petersen2

1 Faculty of Fisheries, Ege University, Izmir, Turkey 2 Darling Marine Center, University of Maine, Walpole, Maine, USA

Cirratulus dollfusi Fauvel, 1928 is redescribed from the holotype and non-type material from muddy substrate at 449 m in the Sea of Marmara. The type locality is “Vanneau” station 108, off the coast of Morocco. The species is a multitentaculate and multibranchiate cirratulid; it differs from all other known cirratulid genera in its types of chaetae and the way the multiple branchial fil- aments arise from the notopodia. Chaetae are of two types: numerous long, fine capillaries in both rami throughout, and from chaetiger 13 in our material, also 2-4 shorter, wider, finely tapering spines in noto- and neuropodia. There are no slightly flattened sigmoid spines, typical of most Cirratulus. Very short, slender grooved tentacles arise in a small circular group on either side of chaetiger 1, with about 25 in each group. Branchial filaments are multiple vs. single; they arise as 1-2 filaments from each of 4-8 raised notopodial lobes on parapodia of anterior and middle seg- ments, with lobes fading out and branchiae fewer (holotype) or absent (our material) posteriorly. Multiple branchiae are found in several other multitentaculate species, but do not arise from multi- ple raised notopodial lobes. There are also major differences in the chaetae; no other cirratulid gen- era appear to have straight, tapering spines plus so many fine capillaries. We propose that a new genus be established for this species. The largest specimen (110 mm long) seen by us had eggs (diameter: 58-80 µm) in its coelomic cavity. The species seems most closely related to Cirratulus hedgpethi Hartman, 1951, from the northern Gulf of Mexico, still only known from the incomplete original description. Features of some cirratulid genera are compared and the use of multiple branchiae as a generic character is discussed.

Presenter (*) 112 Poster Abstracts

Morphometric differences of Polydora neocaeca (Polychaeta: Spionidae) living on shells and inside mud-blisters of Mytella charruana (Mollusca: Bivalvia)

Rachel Furioso Daolio, Fabio Sá MacCord, & Antonia Cecilia Zacagnini Amaral

Depto. de Zoologia, Instituto de Biologia, Universidade Estadual de Campinas, Caixa Postal 6109, Barão Geraldo, Campinas, São Paulo 13083-970, Brasil

Some species of polydorids bore into calcareous substrates such as corals or mollusk shells. They also live on the surface of these substrates. The aim of this study was to determine which relative growth model (linear, quadratic, or cubic) best explains the pattern of body increase of Polydora neocaeca, and also the possible differences between the patterns of the animals collected on the shells of the bivalve Mytella charruana from those collected from inner shell layers, within mud- blisters covered by the nacreous layer. Fifty individuals living on the shells, and 30 from inside mud-blisters were sampled. Intact worms were analyzed, and 16 variables were related to total body length. For individuals found on the shells, the variables most related to total length were the num- ber of setigers (R≤=0.890; p<0.05), volume (R≤=0.776; p<0.05) and width (R≤=0.767; p<0.05) of setiger 3; the linear model best explained the growth pattern of these relationships. For individuals from mud-blisters, the best-related variables were the area of setiger 7 (R≤=0.857; p<0.05), length of the prostomium (R≤=0.778; p<0.05), and volume of setiger 5 (R≤=0.755; p<0.05). The model that best suited the first two relationships was the cubic one, and the last relationship best fit the lin- ear model. These significant differences between the relative growth of individuals collected in the two different conditions suggest a strong influence of the microhabitat on their pattern of body increase. [Support: FAEPX/Unicamp, CNPq, CNPq/PIBIC, FAPESP]

Presenter (*) 113 Poster Abstracts

An interesting new species of Diplocirrus from the southern Irish Sea

Darbyshire, T.* & A.S.Y. Mackie

National Museum Wales, Cardiff, Wales, UK

There are currently six species assigned to Diplocirrus worldwide. Within UK waters, only Diplocirrus glaucus (Malmgren, 1867) is common. Recent studies in the southern Irish Sea have revealed a new species of Diplocirrus. The new species is found only in coarse sediments, unlike D. glaucus which occurs in finer sediments. The new species can be immediately distinguished from D. glaucus by an absence of any encrusting sand grains, a body wall covered in large, globular papillae and the absence of a cephalic cage. The new species appears closest to D. capensis Day, 1961 from South Africa, differing mostly in the form of the epithelial papillae. The morphological characters of the genus are examined and discussed.

Presenter (*) 114 Poster Abstracts

Pattern of polychaetes diversity around an oil well on the southern Brazilian shelf de Almeida, Tito César M., Maikon Di Domenico* & Thiago Emílio Rohr

Universidade do Vale do Universidade do Vale do Itajaí, Itajaí, Brazil

Polychaete diversity was analyzed around an oil well placed at the shelf break at 190 m depth six months after its start-up. Sediment samples were collected during an oceanography survey with a 50 x 50 box core thrown three times at eight stations placed in a sequence of 250, 500, 1000 and 3000 m from the well. Two subsamples for faunal analyses were taken from each box with a 10-cm- diameter plastic tube and an additional sample for sediment grain composition. The polychaete associations around the oil well were analyzed according to total density, number of species, Shannon index, species composition, rarefaction, and species dominance curves. The sediments up to 500 m were best-sorted and presented higher mean grain size than at 1000 and 3000 m. A total of 73 species were identified, with Sigambra grubei, Paradiopatra hartmanae, Typosyllis variegata, Schistomeringos rudolphi and Linopherus ambigua the most abundant. Total density, number of species and Shannon index showed the same pattern, where the smallest values were detected at 250 m, the highest at 500 m and intermediate values at 1000 m and 3000 m. Distances of 250 and 500 m, showed higher dominance than at 1000 and 3000 m. The similarity analyses showed signifi- cant differences between the distances. Polychaete diversity distribution around the oil well showed that the highest values were found at the intermediate distance (500 m). Our result is in accordance with the intermediate disturbance hypothesis that says the highest values of richness and abundance were found in areas with intermediate intensity of disturbance.

Presenter (*) 115 Poster Abstracts

Monticellina (Cirratulidae) species from Costa Rica with a morphologically-based phylogenet- ic analysis of the genus.

Dean, Harlan1* & James A. Blake2

1 Museum of Comparative Zoology, Harvard University, Massachusetts, USA 2 ENSR Marine & Coastal Center, Woods Hole, Massachusetts, USA

In this study we describe eight species in the genus Monticellina collected from intertidal and shal- low-water sites on the Pacific coast of Costa Rica. The ranges of M. cryptica Blake, 1996, previous- ly reported from shelf depths off California, and M. tesselata (Hartman, 1960), previously recorded from shelf and slope depths off California, are extended to shallow waters in the tropical eastern Pacific. Six species are new to science. A review of characters assigned to species of Monticellina suggests that there is considerable variation in morphology among these species and others reported from the literature. Morphological variation is evident in the form of the peristomium, origin of the tentacles and branchiae, and details of the serrated setae. A review of the 17 known species of Monticellina, based upon morphological characters, was conducted.

Presenter (*) 116 Poster Abstracts

A new species of Australonuphis (Polychaeta: Onuphidae) from eastern Pacific de León-González, J.A.*, H. Cornejo & S. Degraer

Universidad Autónoma de Nuevo León, Nuevo León, México

A new species of Australonuphis Paxton 1979 from the Ecuadorian coast, eastern Pacific, is described. This constitutes the fourth record of the genus Australonuphis along the eastern Pacific. This genus currently consist of six species, four American and two Australian: A. beltrani de León- González and Góngora-Garza 1993 from México; A. casamiquelorum (Orensanz 1974) from Brazil and Argentina; A. hartmanae (Friedrish 1956) from El Salvador; A. parateres Paxton 1979 and A. teres (Ehlers 1868) both from Australia; and A. violacea Rozbaczylo and Castilla 1981 from Chile. The new species is characterized by seven modified parapodia directed anterolaterally, cirriform ventral cirri on the anterior 16 to 18 chaetigers, and subacicular hooks from chaetiger 43 to 50. This species belongs to the species group with unidentate pseudocompound hooks. Other species of this group are A. beltrani, A. hartmanae, A. teres and A. parateres.

Presenter (*) 117 Poster Abstracts

Redescription of Dipolydora armata (Largerhans, 1880) (Polychaeta: Spionidae) and a new species of Dipolydora from the Grand Caribbean region

Delgado-Blas, Víctor Hugo

Universidad de Quintana Roo, Quintana Roo, México

In this study Dipolydora armata (Langerhans, 1880) is redescribed based on paratypes in the Naturhistorisches Museum Vienna, Austria (NHMW). Main characteristics of this species are a bilobed prostomium; branchiae from setiger 7, numbering 4-6 pairs, flat, basally fused to notopodial lamellae; posterior segments with long acicular spines, each bundle of spines arranged in a spiral, major spines with two teeth connected by flange on one side, without bristles; hooks bidentate, with slightly curved shaft without constriction from setiger 7; and a glandular, cup-shaped pygidium, with slight ventral notch and dorsal medial gap. Material earlier recorded from the Grand Caribbean region as D. armata was reexamined and described as a new species.

Presenter (*) 118 Poster Abstracts

Distribution patterns of interstitial polychaetes in sandy beaches of southern Brazil

Di Domenico, Maikon,1* Paulo da Cunha Lana2 & André R. S. Garraffoni3

1 Universidade do Vale do Universidade do Vale do Itajaí, Itajaí, Brazil 2 Universidade Federal do Paraná, Centro de Estudos do Mar, Pontal do Sul, Brazil 3 Universidade Estadual de Campinas, São Paulo, Brazil

The present study analyzes the distribution patterns of interstitial polychaetes along a morphody- namic gradient made up by six exposed sandy beaches in the States of Santa Catarina and Paraná (S Brazil), in winter and summer conditions. In each of three random transects at each beach two points were determined, one at the swash and the other at the surf zone. At each point six sediment replicates were collected with a 4.6 cm internal diameter corer buried 10 cm into the sediment. Polychaete composition and abundance were correlated with environmental variables by a Canonical Correspondence Analysis (CCA). The factorial ANOVA showed that taxa richness (F=30,2; p<0,001), average abundances (F=54,85; p<0,001) and Shannon diversity (F=23,85; p<0,001) were significantly higher in reflective beaches in both hydrodynamic zones (swash and surf zone) and time of the year. The composition of interstitial polychaete associations was signifi- cantly correlated with the beach morphodynamics (p<0,01). Protodrilus spp., Saccocirrus spp., Hesionides sp., Hesionura sp. and Polygordius sp. abundances were related with higher breaking waves, higher slope of beach face and coarser sand. Protodriloides sp. 1, and Protodriloides sp. 2 were correlated with higher carbonate and chlorophyll a concentrations. Dinophilus sp. was corre- lated with dissipative surf zone and higher temperatures. Protodriloides sp. 1, Protodriloides sp. 2, and Dinophilus sp. also were correlated with fine sand. Polychaete associations from reflective beaches were more diverse than other beach types. Intermediate beaches can sustain more diverse associations, due to the seasonality of morphodynamic patterns. Conversely, extremely dissipative beaches with compacted sediment seem to disfavor the occurrence of interstitial polychaetes.

Presenter (*) 119 Poster Abstracts

The Nephtys pharynx: a unique food processor!

Dinley, R.R.L., 1* L.E.H. Hawkins, G.L.J. Patterson2 & A. Ball

1 National Oceanography Centre, Southampton University, Dorset, UK 2 The Natural History Museum, London, UK

Many authors over the past century have observed that the intestinal tracts of most wild-caught Nephtys have been found to be empty. This was thought to be accounted for in part, by their pre- sumed carnivorous feeding. However, even an easily digestible carnivorous diet would be expected to contain some refractile material that might be expected to traverse the gut. The answer to this rid- dle may lay in its unique pharyngeal design and muscle function. Its striated muscles are not only unique in containing large quantities of calcium phosphate granules in their sarcoplasmic cores, but in their special construction and layout shown in SEM and confocal microscope pictures. These reveal that the Nephtys pharynx functions rather like an “automobile crusher,” in that after ingesting its prey, it contracts and transforms itself from a circular to a cruciform cross section thus complete- ly filling the lumen and crushing it contents. Once crushed, the nutrient-rich liquids extracted from prey item pass into the gut via a short valvular esophagus with a narrow aperture where they are rapidly digested leaving no refractile material. Large fragments cannot pass beyond this point and are egested. The poster demonstrates this in a photographic series and the muscle formations in 3D.

Presenter (*) 120 Poster Abstracts

Polychaete community structure of three artificial reefs in Tampa Bay, Florida, USA

Dix, Thomas L.*, David J. Karlen & Thomas M. Ash

Environmental Protection Commission of Hillsborough County, Tampa, Florida

The Environmental Protection Commission of Hillsborough County’s Artificial Reef program was started in 1986 to promote habitat diversity and recreational fishing in Tampa Bay. Community structure and seasonality of polychaetes for the artificial reefs in Tampa Bay has never been studied. Three artificial reefs were chosen for this study: Old Tampa Bay, Middle Tampa Bay, and Lower Tampa Bay. Ten samples (16 cm x 16 cm area) were collected by SCUBA divers from each reef from March through April 2004 (dry season) and again in August 2004 (wet season) for a total of 60 samples. Sample sites on the reef were randomly selected for one of three different reef levels: top, middle, and bottom, and one of three surface orientations: horizontal, inverted, or vertical. A total of 20,778 polychaetes representing over 117 species from 29 families were identified from the 60 sites. Five families comprised 52% of the overall species richness (Syllidae 18%, Spionidae 10%, Terebellidae 10%, Sabellidae 8%, and Cirratulidae 6%). Three families comprised 85% of the overall abundance (Syllidae 39%, Spionidae 35% and Cirratulidae 11%). Dominant species that were common to all reefs and seasons were Polydora websteri, Dipolydora socialis, and Syllis gra- cilis. Variations in polychaete community structure between reefs in different bay segments as well as seasonal differences on individual reefs were apparent. Ordination analysis indicated that the polychaete community structure on the reefs in Middle and Lower Tampa Bay were more similar than the reef in Old Tampa Bay.

Presenter (*) 121 Poster Abstracts

New species of Aphelochaeta (Polychaeta: Cirratulidae) from deep water off northern California

Doner, Stacy A.* & James A. Blake

ENSR Marine & Coastal Center, Woods Hole, Massachusetts, USA

The Cirratulidae is one of the most dominant infaunal polychaete families in continental slope sedi- ments off northern California. As part of an extensive reconnaissance program off San Francisco and vicinity in 1990–1991 to identify potential deep-water disposal sites for dredged material, a total of 25 species of Cirratulidae in five genera were identified. Subsequent monitoring of the San Francisco Deep Ocean Disposal Site (SF-DODS) off the Farallon Islands at a depth of 2400–3775 m has consistently yielded 14–16 cirratulid species in each annual survey. Most of the taxa from these two programs are in the genera Chaetozone (8–10 species) and Aphelochaeta (10–12 species). Among the species of Aphelochaeta, only two species, A. glandaria and A. monilaris, have been described previously. The three most abundant Aphelochaeta species are new to science and are described in this paper. All three of these species are most readily identified by their methyl green staining patterns, which range from speckling to a more distinctive banding pattern along the body. Morphology of the prostomium, peristomium, overall body shape, and degree of inflation of the posterior end further distinguish these species. [This study was supported by the National Science Foundation under Grant No. DEB-0118693 (PEET) to James A. Blake, University of Massachusetts, Boston.]

Presenter (*) 122 Poster Abstracts

The poecilochaetids of western Thailand, with the description of six new species (Polychaeta: Poecilochaetidae)

Eibye-Jacobsen, Danny

Danish Natural History Museum, Zoological Museum, Copenhagen, Denmark

The poecilochaetid polychaetes of the Thai sector of the Andaman Sea are described. A total of 17 species was observed, a considerable number in a family previously known for 27 valid species and 2 unnamed forms. Of the 17 species reported here, seven have previously been named, six are newly described and four represent new forms that cannot be formally named due to the paucity of available material. This new material from Thailand expands the bounds of known morphological variation in this family in several ways. Thus, Poecilochaetus n. sp. 3 is unique in having ampulla- ceous postchaetal lobes (APL) limited to chaetigers 7–9; P. n. sp. 4 has genital pouches similar to those found in spionid genera such as Laonice; P. n. sp. 5 has distinctive postchaetal lobes and a unique distribution of neuropodial hooks on anterior chaetigers; and P. n. sp. 6 is the first named papillate species of the genus with APL limited to chaetigers 7–10. Furthermore, one of the unnamed forms differs from all known species in having well developed dorsal postchaetal lobes on chaetiger 1. Another has a nuchal organ with three elongate lobes, but differs from all previously known species with this type of nuchal organ in having APL limited to chaetigers 7–12. Finally, a third unnamed form is unique among papillate species in likewise having APL on chaetigers 7–12. [Note: In order to avoid future confusion, new taxon names are not provided here.]

Presenter (*) 123 Poster Abstracts

A first look at Cirratulidae (Polychaeta) from Argentine Sea (SW Atlantic), with the descrip- tion of three new species

Elías, Rodolfo* & Maria Silvia Rivero

Universidad Nacional de Mar del Plata, Buenos Aires, Argentina

Cirratulidae off Mar del Plata (38º S, 57º W) were revised and summarized. The area is interesting because it belongs to a warm-temperate region from southern Brazil to northern Argentina. The area is divided by the Rio de la Plata but constitutes a single biogeographical region. The city (more than 600,000 inhabitants) produces sewage discharge continuously (2.5 m3.sec-1) but peaks 60 % greater in summer (when 2 million tourists arrive). The outfall is intertidal and several polychaetes are associated with both intertidal and subtidal communities in organically enriched areas. Five new species of cirratulid polychaetes are fully described, with illustrations and SEM photographs. Two polychaetes belonging to the genus Caulleriella are new species for science, one from intertidal and shallow waters and the other from an aquarium. The genus Protocirrineris is first mentioned for Argentine waters and a new species is described from organically enriched intertidal areas. Live specimens of Protocirrineris sp. nov are under observation in aquaria, and asexual reproduction and high regeneration rates have been observed. On the other hand, the presence of the genus Aphelochaeta and Chaetozone are also new records for argentine waters, in sand bottoms off the outfall; both species are new to science.

Presenter (*) 124 Poster Abstracts

Assessing urban contamination using intertidal polychaetes on sandy beaches in the Patagonia (Puerto Madryn, 42º45' S, 65º02' W), Argentina

Ferrando, Agustina, Jose Luis Esteves & Rodolfo Elías*

Universidad Nacional de Mar del Plata, Buenos Aires, Argentina

Several impacts affect the marine environment, their assessment being one of the major goals in any study. Due to their low mobility, the macrobenthos, and polychaetes in particular, are fundamental tools for assessing environment health. In this study we analyze infaunal organisms at three urban sandy beaches of Puerto Madryn (outfall of a fisheries factory and two pluvial effluents in Moreno and 28 de julio streets) and two control sites. Five replicated cores in the lower and middle intertidal zone, and environmental variables of interstitial water and sediments, were obtained every three months. Preliminary data from November 2005 show anthropogenic-induced disturbance. Highly sig- nificant differences were recorded between S (species number) in levels, while N (mean abundance), H' (Shannon) and J' (Pielou) showed no significant differences. Highly significant differences were detected among sites (mean abundance at the Fisheries site was 3,927 individuals, and 1,033 individ- uals at 28 de julio, but low abundance in Moreno (125 individuals) and in the two control sites at Doradillo 1 y 2 (227 and 198 individuals). Polychaetes are always dominant. High values of ammo- nium, phosphates, nitrites, and organic matter were related to Fisheries and 28 de Julio, as well as Boccardia polybranchia and Capitella “capitata” sp., but high Eh, nitrate, and dissolved oxygen were related to Moreno with Paraonides sp. and in control sites with an unidentified Psammodrilidae (probably a new species, according to Lobo Orensanz). The impact in urban areas in relation to efflu- ents is clear, as is the proper use of polychaetes as indicators of environmental health.

Presenter (*) 125 Poster Abstracts

SEM observations on Archinome (Annelida: Polychaeta) from hydrothermal vents in the Pacific and Atlantic

Fiege, Dieter & Gordon G. Bock*

Forschungsinstitut und Naturmuseum Senckenberg, Frankfurt, Germany

Archinome rosacea (Blake, 1985) is the only species of the Amphinomida known to occur at hydrothermal vents. To date it has been recorded from the East Pacific Rise (Galapagos Rift and Guaymas Basin) but also identified as Archinome sp. aff. rosacea from the Logatchev field on the Mid Atlantic Ridge and as Archinome cf. rosacea from the Kairei field on the Central Indian Ridge. Archinome rosacea was originally referred to the genus Euphrosine (Polychaeta: Euphrosinidae) but later redescribed by Kudenov, who referred it to the newly established genus Archinome for which he erected the new family Archinomidae. SEM investigations on specimens collected during various cruises with RV Sonne and RV Meteor in the Pacific and Atlantic Ocean, revealed morphological differences among populations from different geographical locations (Pacific Antarctic Ridge, North Fiji and Lihir Basin, Mid Atlantic Ridge). Based on our results, it appears likely that at least one additional species of Archinome can be distinguished.

Presenter (*) 126 Poster Abstracts

A new species and a new occurrence of Eusyllis Malmgren, 1867 (Syllidae: Eusyllinae) in Brazil

Fukuda, Marcelo Veronesi & João Miguel de Matos Nogueira*

Universidade de São Paulo, São Paulo, Brazil

Among eusyllines, Eusyllis Malmgren, 1867, is characterized by having pharynx with an incom- plete trepan at the anterior border and with a central anterior tooth. A new species of Eusyllis was found among material collected on rocky shores off the coast of the State of São Paulo, southeast- ern Brazil, by the projects “BIOTA/FAPESP/Benthic Marine Biodiversity” and “Biodiversity of Annelida Polychaeta on Rocky Shores along the State of São Paulo.” Eusyllis sp. n. has dorsal pig- mentation as two transverse dark bars per segment, one close to the anterior border of the segment, the other posteriorly; anterior parapodia with about 9–10 falcigers each, 3–4 falcigers on each pos- terior parapodium; falcigers with unidentate, falcate blades, with inverted dorsoventral gradation in length, blades of dorsal-most chaeta about half as long as ventral-most chaeta and more strongly curved; trepan with eight tiny teeth on dorsal half, ventral half of trepan irregularly serrated; anteri- or border of pharynx surrounded by 10 soft papillae, each with a longitudinal row of cilia; proven- tricle occupying 2.5–3 segments, with about 30 rows of muscle cells. Eusyllis sp. n. resembles E. kupfferi Langerhans, 1879, another species found in this study and a new record for the Brazilian coast, by having falcigers with unidentate blades, but these species are distinguished by the charac- teristic “bayonet-like” dorsal simple chaeta of E. kupfferi, and because E. kupfferi presents a differ- ent pattern of pigmentation, with two reddish-brown dorsal bands per segment, one of which situat- ed dorsolaterally, close to anterior border of the segment, the other situated mid-dorsally, close to the posterior border. In addition, no other currently known species of Eusyllis has inverted gradation in length of the blades of falcigers, as present in our new species.

Presenter (*) 127 Poster Abstracts

Two new occurrences of Erinaceusyllis San Martín, 2005 (Syllidae: Eusyllinae) in Brazil

Fukuda, Marcelo Veronesi & João Miguel de Matos Nogueira*

Universidade de São Paulo, São Paulo, Brazil

Erinaceusyllis San Martín, 2005, is characterized by having a prostomium with three antennae, four eyes and two anterior eyespots; dorsal cirri usually absent on chaetiger 2; antennae and cirri throughout with bulbous base and narrower tip; narrow pharynx, with single anterior tooth, some- times slightly away from the anterior margin; and proventricle long and wide. In the material col- lected on rocky shores by the project “BIOTA/FAPESP/Benthic Marine Biodiversity” (northern coast of the State of São Paulo, Southeastern Brazil), two new occurrences to Brazilian shore were found; these new occurrences are herein described. Erinaceusyllis perkinsi (Riser, 1991) has fal- cigers with unidentate blades, with marked dorsoventral gradation in length, blades measuring 26–120µm on anterior parapodia, 20–130µm from midbody, pygidium with prominent triangular papilla between anal cirri and proventricle extending for 3–4 chaetigers, with about 20 rows of mus- cle cells. Erinaceusyllis belizensis (Russell, 1989) has bidentate blades only on the dorsalmost fal- ciger of each parapodium, remaining blades unidentate, or with a subdistal spine, and proventricle extending through 2–2.5 segments, with 13–15 rows of muscle cells. These two new occurrences bring to seven the number of species of Erinaceusyllis reported for Brazil; previously, E. cryptica (Ben-Eliahu, 1977), E. centroamericana (Hartmann-Schröder, 1959), E. cf. erinaceus (Claparède, 1863), E. mussismiliaicola (Nogueira, San Martín & Amaral, 2001) and E. subterranea (Hartmann- Schröder, 1960) had been recorded for Brazil, all of them occurring in the State of São Paulo.

Presenter (*) 128 Poster Abstracts

Notomastus (Polychaeta: Capitellidae) from the Mexican Pacific

García-Garza, María Elena* & Jesús Angel de León-González

Universidad Autónoma de Nuevo León, Nuevo León, México

The Capitellidae is one of the dominant polychaete families on the Mexican Pacific coast. One of the most important genera is Notomastus; 13 species are known from that area: N. aberans, N. abyssalis, N. americanus, N. angelicae, N. cinctus, N. (Clistomastus) lineatus, N. hemipodus, N. latericeus, N. lobatus, N. magnus, N. sonorae, N. precocis and N. tenuis. However, we infer that some of these species were erroneously identified. We have revised the species reported for the area that are deposited in diverse Mexican collections (Instituto de Ciencias del Mar y Limnología UNAM, Instituto de Ciencias del Mar y Limnología Unidad Mazatlün, El Colegio de la Frontera Sur, Unidad Chetumal, Universidad del Mar, Universidad Autónoma de Nuevo León), as well as the material col- lected in two sampling campaigns in the intertidal of the Mexican Pacific coast in 2005 and 2006. The analyzed specimens were compared with the type material deposited in diverse museums. We used methyl green to obtain the staining pattern of each species, and some were made transparent with Hoyer’s liquid to observe their morphology in more detail. Of the species previously reported for the Mexican Pacific costs, four were erroneously identified (N. aberans, N. americanus, N. (Clistomastus) lineatus and N. latericeus). In this work, 16 species are included, five of which are considered potentially new for science; the range of geographical distribution of N. polydon and N. annulus are also extended, the first described from Vietnam and the second from Australia.

Presenter (*) 129 Poster Abstracts

Ultrastructural observations of an unusual sensory structure in the cerebral ganglion of Owenia fusiformis and Myriochele sp. (Polychaeta: Oweniidae)

Gardiner, Stephen L.*, A. K. Dewan, M. L. Schwartz, J. Cannon & B. F. Dickey

Bryn Mawr College, Bryn Mawr, Pennsylvania, USA

In his monograph on the morphology and development of the mitraria larva of Owenia fusiformis, Wilson illustrated a pair of structures he termed “eyes” associated with the paired lobes of the cere- bral ganglion, but he did not provide any description of their organization. We examined the cere- bral ganglia of the mitraria larvae of Owenia fusiformis and Myriochele sp. by transmission electron microscopy and located a sensory structure of unusual organization that may correspond to the “eye” noted by Wilson. Unlike Wilson’s claim of a pair of “eyes,” we observed only one of these sensory structures in the cerebral ganglia of both owneniid species. The sensory structure consists of a crescent-shaped group of monociliated cells whose cilia are directed into a specialized depres- sion formed by the invagination of the apical plasma membrane of a centrally situated, non-ciliated cell. The cilia and depression extend deeply into this cell, and small microvilli extend from the plas- ma membrane of the depression and interdigitate with the cilia. In the region of its nucleus, the non- ciliated cell sends a process into a closely situated neurite bundle. Ciliary photoreceptors are wide- spread among metazoan groups, and it is possible that this sensory structure represents a spe- cial/unique type of photoreceptor in the oweniids that may assist the larva at time of settlement, ini- tiating negative phototactic behavior. However, other types of sensory receptors utilize cilia. Alternatively, this sensory structure may act as a mechanoreceptor to help the larva maintain its ori- entation within the water column.

Presenter (*) 130 Poster Abstracts

Reproduction and development in Nicolea uspiana (Polychaeta: Terebellidae)

Garraffoni, André Rinaldo Senna * & Antonia Cecilia Zacagnini Amaral

Universidade Estadual de Campinas, São Paulo, Brazil

The reproduction and development of Nicolea uspiana (Nogueira, 2003), a common polychaete of rocky shores in northern São Paulo, Brazil, was studied on the coast at Itararé, São Vicente, by monthly samples over a 12-month period. The maximum length and oocyte diameter of females were measured, and reproductive features were examined by serial sections under light microscopy. Modifications in morphological characteristics during ontogenetic development occurred, including an increasing number of buccal tentacles, eyespots, segments with notopodia (up to 17 pairs), and loss of the first two pairs of noto- and neuropodia. Members of this species are gonochoric and lack clear external sexual dimorphism. The initial gamete stages are produced in a special structure called nephromixia, a complex organ serving excretory and reproduction functions. Oogenesis is extra-ovarian, and the germ cells are solitary without any type of accessory cells, or layers of folli- cle cells around clumps of cells. These cells are ovulated into the coelomic fluid and yolk synthesis occurs in this cavity. The maximum oocyte size found, 225 µm, showed that these eggs fall into the size range for lecithotrophy. Male gonads release germ cells early in development, and sperm matu- ration also occurs in the coelomic fluid. The male gametes consist of flattened plaques of germ cells attached on their anterior part by a cytophore, which does not dissolve during formation of the sper- matozoa, assuming a rosette-like appearance. Following maturation of the male cells, the spermatids produce arrays of stiffly vibratile tails, assuming a morula shape.

Presenter (*) 131 Poster Abstracts

Phylogeny of Terebellidae (Polychaeta) and the problem with low phylogenetic support for the generic Linnean categories

Garraffoni, André Rinaldo Senna1* & Paulo da Cunha Lana2

1 Universidade Estadual de Campinas, São Paulo, Brazil 2 Universidade Federal do Paraná, Centro de Estudos do Mar, Pontal do Sul, Brazil

The phylogenetic relationships of the family Terebellidae (Polychaeta), including an assessment of the current taxonomic status of the Trichobranchinae, were studied through a parsimony analysis of 79 characters of external and internal morphology and ecological features. The ingroup terminals included 96 species of 56 different genera representing the four terebellid subfamilies. The outgroup taxa included three species of Ampharetidae and two of Alvinellidae. The monophyly of the Terebellidae was clearly supported by the presence of prostomium shape as a dorsal ridge-like struc- ture; prostomium with buccal tentacles; ventral glandular area with distinct pads; and buccal tentacles not retractable into the mouth. However, only the subfamilies Polycirrinae and Trichobranchinae appeared as monophyletic after the parsimony test. The absence of any synapomorphy to support the monophyly of the Thelepodinae was notable, as in previous analyses, which supports the idea that this is not a natural taxon. On the other hand, the apparent non-monophyly of Terebellinae can be explained by problems with the coding methods used in the present analysis. The hypothesis that the trichobranchins form a clade within the terebellids is supported and we present evidence to justify their subfamily status under a Linnean classification. Most of the currently recognized genera in the family lack phylogenetic support, because they are defined based on homoplastic or plesiomorphic features. Only five of them can be considered monophyletic because of sharing exclusive synapo- morphies, and these evolutionary novelties are not present in their generic diagnoses. A Linnean re- classification based on autapomorphies of genera is currently needed.

Presenter (*) 132 Poster Abstracts

The Abyssal Polychaete Intercalibration Project (APIP): a CeDAMar project funded by the Census of Marine Life to undertake taxonomic work on abyssal polychaetes

Glover, A.G.1*, G. P. Paterson1, C.R. Smith2 & B. Ebbe3

1 The Natural History Museum, London, UK 2 University of Hawai’i at Manoa, Honolulu, Hawai’i 3 Forschungsinstitut Senckenberg, Bonn, Germany

The abyssal plains of the world’s oceans are thought to harbor a very large proportion of global polychaete diversity. Recent research has suggested that between 60 and 80 percent of species recovered from these areas are new to science. Given that this environment covers almost 50 per- cent of the Earth’s surface, it is perhaps surprising that there are so few polychaete taxonomists in the world, and perhaps even more unfortunate that most of these taxonomists work on shallow- water species. One stumbling block has been that most recent abyssal expeditions have not resulted in published taxonomic names; rather these data have been used for isolated studies of ecological biodiversity from the region of interest using putative morphotyped species (sp. A, B, C etc.). This lack of funding for regional and global taxonomic syntheses has hindered attempts to understand regional and global biodiversity patterns at a time when many areas of the abyss are under threat from human activities such as mineral extraction, oil exploration, and carbon sequestration. We report here on the results of the APIP workshop where these issues were discussed, and participants examined abyssal material from a range of global sites to exchange taxonomic data. We propose a web-based taxonomic exchange system (wiki-style scratchpads), with collaborative authoring, to enable regionally based researchers to intercalibrate their abyssal taxonomic datasets.

Presenter (*) 133 Poster Abstracts

Evidence of sibling species in Lysidice ninetta (Polychaeta, Eunicidae) in the Mediterranean Sea, revealed by molecular and morphological analyses

Iannotta, Maria Alessandra, Maria Cristina Gambi* & Francesco Paolo Patti

Stazione Zoologica Anton Dohrn, Naples, Italy

A previous study on the phylogeography of Lysidice ninetta Audouin & Milne-Edwards (Polychaeta, Eunicidae) in the Mediterranean Sea, and based on the molecular ITS and COI analy- ses, revealed the occurrence of possible sibling species. In the framework of a program aimed at defining the taxonomy, phylogeny, and ecology of species of the genus Lysidice in the Mediterranean and Caribbean Seas, we report further evidence on the occurrence of such sibling species within L. ninetta, revealed by both molecular and morphological analyses. The specimens were collected in a Posidonia oceanica meadow (Cava) off the island of Ischia (Naples, Italy), one of the locations where such putative siblings co-occurred. The molecular marker selected was the conservative mitochondrial gene 16S, which was sequenced in 42 specimens. Two haplotypes were found, a less frequent one (nA) was identical to the sequence reported in the literature (gene bank) for L. ninetta, while a more common one (nB) was unique to the studied “Cava” site. The two hap- lotypes were differentiated by 72 variable sites (13%). A parallel morphological analysis was con- ducted on most of the individuals genetically defined, and on additional material from the same site. A comparison of the two analyses revealed the presence of a morphotype (“dark”) that was charac- terized by a typical dark color pattern on the prostomium and anterior segments, matching well with the description of the best known L. ninetta, and that corresponded to the haplotype nA. The other morphotype (“light”), was characterized by a lighter coloration of the prostomium and anterior seg- ments, and corresponded to the haplotype nB, suggesting the presence of a different species.

Presenter (*) 134 Poster Abstracts

Trends in the polychaete community near a shallow-water hydrothermal vent in Papua New Guinea

Karlen, David J.*, Roy E. Price, Thomas Pichler & James R. Garey

Environmental Protection Commission of Hillsborough County, Tampa, Florida, USA

The infaunal polychaete community was characterized along an environmental gradient from a shal- low-water (depth = 10 m) hydrothermal vent at Tutum Bay, Ambitle Island, Papua New Guinea. Samples were collected at nine sites located from 0 to 300 m from the vent at 30–50 m intervals. Additional samples were collected at a reference site located approximately 1.5 km away. A 1-m2 sampling grid was placed adjacent to the transect line at each site. A sediment core sample (diame- ter = 7.62 cm) was taken randomly within the grid. Sediment and pore water samples were collect- ed within the grid for corresponding physiochemical analysis. The sampling grid was then reposi- tioned and the procedure was repeated for a total of five replicate samples. The core samples were sieved through a 0.5-mm mesh screen. The retained fraction was fixed in 10% buffered formalin. Most polychaete taxa were represented by only a few individuals. The notable exception was Capitella cf. capitata, which was dominant in the immediate vicinity of the vent (mean = 23 indi- viduals per core). Other frequently occurring taxa included Heteropodake sp. A, which was com- mon at most of the transect sites as well as the reference site. There was a general trend of increas- ing diversity relative to distance away from the vent as well as differences in species composition. These results correlated with trends in increasing pH, decreasing temperature, arsenic concentra- tions and changes in sediment composition (increasing median grain size and sediment carbonates) with increasing distance from the vent.

Presenter (*) 135 Poster Abstracts

Taste bad or hide: interactions among defensive and escape strategies in sabellid worms

Kicklighter, C.E.

Goucher College, Baltimore, Maryland, USA

Numerous studies demonstrate how sessile marine organisms utilize chemical, structural, and nutri- tional deterrents to persist in predator-rich environments. Little is known, however, about how mobile, more behaviorally complex species minimize predation by integrating avoidance and deter- rence strategies. To investigate this, eight sabellid worm species from the Caribbean and temperate western Atlantic were examined for their palatability to generalist fish consumers. Chemical and structural traits mediating unpalatability were then elucidated for those species rejected by con- sumers. In addition, predator escape traits, such as tube strength, speed of radiole retraction, com- pleteness of retraction, and sensitivity to a nearby disturbance were measured for all species. All eight species had unpalatable radioles that were chemically or structurally defended, but only two species had unpalatable, chemically defended bodies. Thus, most species allocated defenses to tis- sues most exposed to predation. The two species with defended bodies (Bispira brunnea and B. var- iegata), relied less on behavioral escapes than other species. Their tubes were weak, they did not retract until disturbances were very close, and B. brunnea retracted slowly and incompletely even when touched. Other (more palatable) species generally had stronger tubes and retracted when dis- turbances were farther away. Interestingly, this trade-off between deterrence and escape strategies even occurred within a single species when populations differed in palatability. Thus, when consid- ering how prey may avoid or deter consumption, it cannot be assumed that all members will inte- grate multiple antipredation strategies the same way.

Presenter (*) 136 Poster Abstracts

Settlement and recruitment of dominant polychaetes in the Yellow Sea, Korea: temporal vari- ation of larval, meio/macrobenthic polychaetes in an intertidal and subtidal area

Koh, B.-S.*, O.-I. Choi, Y.-J. Jo, C.-I. Lee & J.-M. Jun

Tidal-flat Research Center, National Fisheries Research and Development Institute, Kunsan, Republic of Korea

Benthic polychaetes might have different periods of reproduction in different oceans, even though they are same species. Temporal variation of polychaete population levels could therefore be inter- preted as a result of differences in the settlement period and density of young stages. In Asian tem- perate waters such as the Yellow Sea, water temperature fluctuates seasonally, so temporal variation of macrobenthic polychaetes could occur. However, the main reproductive (larval appearance) and high settlement periods of polychaetes in the Yellow Sea have not been reported up to now. Quantitative investigations independent of size, including density of larvae, meiofauna on the sur- face of the sediment and macrobenthic polychaetes in the soft bottom, were carried out monthly at two different stations (an intertidal and subtidal station) in the Yellow Sea in 2005. In this study, the important reproductive and main settlement periods were determined, and temporal variation of some dominant polychaetes could be interpreted as a result of the settlement processes of young polychaetes. For some dominant polychaetes, an increase or decrease of the population was corre- lated with settlement periods and densities. Appearance of larval polychaete was influenced by blooming of phytoplankton and zooplankton in the Yellow Sea.

Presenter (*) 137 Poster Abstracts

A new species of Lumbriclymene (Polychaeta: Maldanidae) from the west coast of Norway, with comments on L. cylindricauda M. Sars, in G.O. Sars, 1872

Kongsrud, Jon Anders

Bergen Museum, University of Bergen, Bergen, Norway

A new species of Lumbriclymene has been described from the west coast of Norway, based on material from monitoring investigations. The species is often found together with L. cylindricauda, and the two have previously been confused. Type material of Lumbriclymene cylindricauda has been examined, and a lectotype has been designated. Morphological differences between the two species have been highlighted. A re-examination of the specimens described by Arwidsson (1907) as Lumbriclymene sp. from western Norway proved them to be identical with the new species described herein. Identification of additional material from Greenland, Iceland, and the Faeroe Islands shows that both species are widely distributed in the north Atlantic, in depths between 50 and 400 m.

Presenter (*) 138 Poster Abstracts

TEM and REM studies on the morphology and ultrastructure of the freshwater polychaete Hypania invalida (Grube, 1860) (Polychaeta: Ampharetidae)

Kremer, Philipp1, Dieter Fiege*2, Volker Storch1 & Thomas Wehe1

1 Zoological Institute, University of Heidelberg, Heidelberg, Germany 2 Forschungsinstitut und Naturmuseum Senckenberg, Frankfurt, Germany

Hypania invalida is a recent invader of the Western European river systems. Reported already from the lower and upper Rhine, the species was recently collected by us from a more median part – the so-called ‘Oberrhein-Ebene’ – several kilometers from Heidelberg. Information to be found on this species is for the most part restricted to early anatomic descriptions based on light-microscopy and more recently on the chronology of the invasion of the rivers Main, Rhine, Meuse and others. So far, nothing was known about the ultrastructure of Hypania invalida and comparable studies on other ampharetid species are generally missing. However, knowledge on the structure of different organ systems is seminal, in order to understand the biology, ecology, adaptation to freshwater and especially the dispersal potential of adventive species. In order to contribute basic data to the clari- fication of some of these topics an ultrastructural investigation of Hypania invalida is currently con- ducted and some selected morphological features will be presented.

Presenter (*) 139 Poster Abstracts

Locomotion and fine structure of parapodia in Myzostoma cirriferum (Myzostomida)

Lanterbecq, Deborah,1* Christoph Bleidorn2, Sabine Michel1 & Igor Eeckhaut1

1 University of Mons-Hainaut, Mons, Belgium 2 University of Potsdam, Golm, Germany

Most myzostomids are ectocommensals of crinoids on which they move freely. Their locomotion is ensured by five pairs of parapodia located laterally below their trunk. Each parapodium in Myzostoma cirriferum is a conical structure that includes a hook-like chaeta, replacement chaetae, and an aciculum. Structure and ultrastructure of the myzostomid chaetae are similar to those of poly- chaetes: they are formed by a chaetoblast, which gives rise to microvilli where chaetal material is assembled on the outer surface. M. cirriferum walks on its host. It moves the anterior part, the poste- rior part, or the lateral parts forward but is able to rotate of 180º on itself. Its locomotion relies entire- ly on parapodial motions and not on trunk movements. Three pairs of muscles are involved in para- podial motions: parapodium flexor and parapodium extensor, aciculum protractor and chaeta retrac- tor, and hook protractor with conjonctor. A functional model is proposed for explaining the global motion of a parapodium in M. cirriferum that may be extended to all ectocommensal myzostomids.

Presenter (*) 140 Poster Abstracts

Dredging activities for beach nourishment in the central Thyrrhenian Sea (Italy): effects on polychaete communities

La Porta, Barbara* & Luisa Nicoletti

ICRAM-Central Institute Of Marine Research, Rome, Italy

The aim of this study is to analyze the effects of relict sand dredging activities on polychaete com- munities, in space and time, in an area offshore Montalto di Castro (central Tyrrhenian Sea - Italy). This area is characterized by relict sand deposits (olocenic paleo-beaches) used for beach nourish- ment operations along the Latium coasts.

The effects of sand extraction on polychaetes communities were investigated before, during and after dredging activities that were carriedpresented out in two different periods (July 2004 and September 2005), using an anchornot dredge and a trailer dredge, respectively. The studied sites were located both in the dredged areas (inside stations) and in the neighboring non-dredged areas (outside stations). Results showed that the impact of sand extraction was confined to a narrow area close to the dredg- ing site. Two months after the first dredging, the polychaete communities of the inside stations were already at an advanced stage of recolonization and the community structure and composition were comparable to those of the pre-dredging period and neighboring non-dredged areas. After the sec- ond dredging, the inside stations were characterized by a different development of the recoloniza- tion process, showing an high variability of community structure, especially in species richness, abundance, and dominant species. The results obtained suggested that changes of sediment charac- teristics (due to sand extraction), biological cycles, ecological characteristics of different species and also seasonal environmental variations are the main factors significantly influencing the recolo- nization process of the impacted areas.

Presenter (*) 141 Poster Abstracts

Sabellaria alveolata (Linnaeus) reefs in the central Tyrrhenian Sea and associated polychaete fauna

La Porta Barbara*, Carla Chimenz Gusso & Luisa Nicoletti

ICRAM-Central Institute Of Marine Research, Rome, Italy

The aim of this research is to analyze the polychaete fauna associated with Sabellaria alveolata reefs in three different Latium coastal areas (Tyrrhenian Sea, Italy) at different depths (between -1 and -2.5 m) and in three periods of the year (winter, spring, and summer). In this study, we try to assess the relationship between the physical structure of the reefs and the associated fauna in order to define assemblages and also understand if the polychaete community structure is related to the reef evolution, in space and time. The polychaetes sampled were identified according to species and their assem- blages were studied using community indexes, multivariate and univariate analysis, and examining the trophic categories. In addition, the density of S. alveolata was analyzed, and reefs were morphologi- cally described. The results have allowed classifying three different states of the reef, which are linked to the respective phase of their life cycle. Moreover, the structure of associated polychaete com- munities differs according to the relative state of the reef’s development. In fact, species richness is very high in degraded reefs and decreases with the recovering state of the reefs. The analysis of poly- chaetes’ feeding guilds underlines that the biodiversity increases in the reef’s degraded phase. In the reef’s growth phase, suspension feeders, mainly S. alveolata, represents most of the polychaetes taxo- coenosis and the remaining categories are reduced in species number and abundance.

Presenter (*) 142 Poster Abstracts

Morphological variability of the Haplosyllis (Syllidae: Polychaeta) species-complex in Australian seas

Lattig, Patricia, Daniel Martin* & Guillermo San Martin

Centre d’Estudis Avancats de Blanes (CSIC), Blanes, Girona, Spain

Large collections of Haplosyllis (Syllidae: Polychaeta), extracted from sponges deposited at the Australian Museum (Sydney), and coming mainly from Western Australia, Tasmania, and Papua New Guinea, have been carefully examined. Haplosyllis basticola Sardá, Avila & Paul 2002, H. crassicirrata Aguado, San Martín & Nishi 2007 and H. (Syllis) violaceo-flava (Grube 1878) were the only three previously known species. In addition, ten different morphotypes have been identified and classified into four groups, according to body size and chaetal features: (1) small specimens with long spines in the serration on the main fang; (2) small specimens without serration on the main fang; (3) medium-sized specimens, with chaetae of different shapes and sizes on each para- podium; and (4) robust specimens with highly variable chaetal features. The sample collection was not specifically designed to address biogeographical issues, and all morphotypes tended to show wide distributions. The same basic problem applies to the assessment of their host specificity, a very interesting question that would certainly require further investigations. The present results demon- strate a high variability of spongicola-like morphotypes within the Haplosyllis Australian seas, con- firming that the genus actually consists of a large complex of cryptic species (most of them new), which show enough taxonomically robust differences to be formally described, as postulated by Martin et al. (2003).

Presenter (*) 143 Poster Abstracts

Niche partitioning by Dorvilleidae at Pacific methane seeps

Levin, L.A.1, W. Ziebis, G.F. Mendoza1*, B. Ebbe2, T. Washington & A.R. Thurber

1 Scripps Institution of Oceanography, La Jolla, California, USA 2 Forschungsinstitut Senckenberg, DZMB, Bonn, Germany

High sulfide concentrations (often 2–20 mM) make methane seep sediments one of the most toxic environments on earth. Dorvilleid polychaetes have a predilection for sulfidic settings and multiple species co-occur at methane seeps off Oregon (OR) and California (CA). Dorvilleid abundance and distribution data, stable isotope signatures (δ13C, δ15N), and environmental sulfide measurements are combined to examine partitioning of species based on geography, water depth, habitat (clam bed, microbial mat), diet, and sulfide tolerance. CA and OR seeps support distinct dorvilleid assem- blages, but with some overlap in species. Certain species appear to specialize on a specific concen- tration of sulfide, or to exhibit broad tolerances (eurysulfidic: 0.05 to >10 mM). Most dorvilleid species exhibit isotope signatures distinct from those of co-occurring dorvilleid species (average δ13C values range from –24 to –46), indicating divergent diets; however, within species signatures vary with location. Settlement preferences, determined from short-term colonization tray deploy- ments with manipulated sulfide levels, reveal some mechanisms for the observed patterns. Colonization patterns reflect local habitat composition, but some species exhibit greater degrees of opportunistic behavior, high sulfide tolerance, or apparent inability to colonize disturbed sediments from the water.

Presenter (*) 144 Poster Abstracts

Sexual dimorphism of a new species of Polydora (Polychaeta: Spionidae) associated with her- mit crabs from Jamaica, West Indies

Luzak, Lara D.* & Jason D.Williams

Hofstra University, Hempstead, New York, USA

A new species of Polydora was found associated with hermit crabs from shallow subtidal coral reefs of Jamaica, West Indies, during 2005-2006. The species bores into approximately 20% of gas- tropod shells inhabited by hermit crabs and exhibits a unique type of sexual dimorphism. One large female (up to 70 setigers) is found in the apex of shells with up to four smaller males (<30 setigers). The males create burrows within the detrital matrix of the female’s tube. Females can be distin- guished from other members of the genus by the morphology of the major spines of the fifth setiger. In addition to a horizontal row of major spines with two lateral teeth, companion setae and ventral capillaries, the fifth setiger contains a group of superior accessory spines. The group of accessory spines consists of one large falcate spine with a channel extending down into the shaft, one spine with a low, rounded tooth and one companion seta. The large falcate spines are similar in morpholo- gy to those found in juvenile Polydora heterochaeta Rioja, 1939 and other polydorids; however, in the Jamaican species the spines are retained in adult females. The small males lack both noto- and neurosetae on segment one and lack the accessory spines of setiger 5. Such sexual dimorphism has not been previously observed in the Spionidae. Results of SEM studies comparing the morphology of male and female worms will be presented. This species is the fourth known obligate commensal polydorid of hermit crabs.

Presenter (*) 145 Poster Abstracts

Postlarval development of Sclerobregma branchiatum Hartman, 1965 (Polychaeta: Scalibregmatidae) and implications for scalibregmatid taxonomy

Luzak, Lara D.* & James A. Blake

ENSR Marine & Coastal Center, Woods Hole, Massachusetts, USA

Scalibregmatids were collected in box-core samples from the Atlantic continental slope and rise during a four-year study from 1983-1986. Specimens originally thought to be a new species of Oligobregma due to lack of branchiae upon closer examination were determined to be juvenile Sclerobregma branchiatum. Specimens ranged from 19 to 52 setigers; prostomial and branchial development were studied. At 19 setigers, the prostomium of S. branchiatum consists of two small lateral lobes with a bulbous anterior region; as worms grow to approximately 43 setigers, the lobes grow to form the characteristic T-shaped prostomium with distinct lateral projections. Branchiae begin as small lobate projections on setigers 3–4 and subsequently develop into well-developed multilobate structures; this process begins at approximately 33 setigers with branchiae being fully formed at approximately 47 setigers. These results indicate that Oligobregma should be syn- onymized with Sclerobregma. They also confirm the difficulty that exists in describing and classi- fying this family of polychaetes at both the generic and specific level. [This study was supported by the National Science Foundation under Grant No. DEB-0118693 (PEET) to James A. Blake, University of Massachusetts, Boston.]

Presenter (*) 146 Poster Abstracts

A comparison of benthic polychaete diversity in tropical, subtropical, and temperate locations

Mackie, A.S.Y.*, T. Darbyshire & K. Mortimer

National Museum Wales, Cardiff, Wales, UK

Despite various literature sources indicating that enhanced diversity occurs in tropical regions, there are relatively few supporting studies for the benthic macroinfauna. Our own quantitative studies of benthic habitats in the Seychelles, Hong Kong, and Wales (UK) have yielded directly comparable datasets of the polychaete assemblages. These are analysed and compared using a variety of uni- variate diversity indices. In addition, taxonomic distinctiveness measures are employed to investi- gate whether any differences in taxonomic composition exist between the assemblages of the three geographic regions. The available literature on benthic polychaete diversity is reviewed.

Presenter (*) 147 Poster Abstracts

Ontogenetic jaw development in two species of Dorvilleidae (Annelida, Polychaeta)

Macnaughton, Martin O.

Zoological Museum, University of Copenhagen, Copenhagen, Denmark

The presence of a jaw apparatus is central in defining the extant Eunicimorph polychaetes, includ- ing Dorvilleidae, where the detailed jaw morphology is of significant systematic importance. The external dorvilleid morphology is highly heterogenous with several minute and interstitial taxa that have been proposed to be neotenic/progenetic due to their resemblance to juveniles of macrofaunal forms. As the dorvilleid jaw apparatus undergoes an ontogenetic transformation, study of the replacement series can be used to compare the jaws of juvenile macrofaunal species and adult minute species, as well as for diagnostic purposes. Previous studies of the ctenognath dorvilleid jaw apparatus have been conducted in detail for some taxa, but the jaws are most often viewed in situ through KOH-cleared specimens or in squash preparations. This study looks at creating ontoge- netic series of jaw development for both Ophryotrocha alborana and Dorvillea albamaculata by SEM of the exposed jaw elements. This approach involves extraction of the jaw apparatus and cleansing it with soft-tissue-digesting enzymes and sodium hypochlorite. The study is hoped to yield new phylogenetic characters as well as insights into the possible neotenic/progenetic develop- ment of some of the interstitial taxa.

Presenter (*) 148 Poster Abstracts

Molecular differentiation of three morphologically similar spionid polychaetes using cytochrome c oxidase subunit I (COI).

Mahon, A. R.,1* D. M. Dauer,2 H. K. Mahon2 & K. M. Halanych1

1 Auburn University, Auburn, Alabama, USA 2 Old Dominion University, Norfolk, Virginia, USA

Spionid polychaetes are a dominant component of benthic assemblages in marine and estuarine habitats and are important in assessing ecological function and integrity. Ecological and biogeo- graphic studies rely upon the ability to distinguish between morphologically similar species as well as knowledge of the evolutionary relationships between species. Distinguishing between congener- ic species can be challenging, for example, within the spionid genus Streblopsio. Streblospio bene- dicti inhabits marine and estuarine sediments throughout the world whereas S. shrubsolii is reported from the Mediterranean Sea, the European Atlantic coasts, and the Baltic Sea. Palp morphology of both S. benedicti and S. shrubsolii are similar, although the two differ in the distribution of prosto- mial papillae, the structure of the branchiae on the first setiger and in reproductive strategies. Another spionid, S. gynobranchiata, is found only in the eastern portion of the Gulf of Mexico and is distinguished from S. benedicti based on its reproductive incompatability and branchiate brood pooches. The goal of this study was to test the limits of these three morphologically similar species utilizing molecular tools, approximately 500 bases of the mitochondrial cytochrome c oxidase sub- unit 1 gene (COI). COI has previously been used to distinguish between Streblospio species; how- ever these studies did not include European populations of S. shrubsolii. The results indicate all three Streblospio species are reciprocally monophyletic with S. shrubsolii basal to a well-supported clade containing S. gynobranchiata and S. benedicti. These data provide molecular evidence distin- guishing species boundaries for three closely related, morphologically similar, but geographically diverse, species of polychaetes.

Presenter (*) 149 Poster Abstracts

Distribution and habitat preference of Pilargidae from Northern Australian waters

Marks, S.A.1* & C. J. Glasby2

1 GHD, Brisbane, Australia 2 Museum & Art Gallery of the Northern Territory, Darwin, Australia

Pilargids are free-living sediment dwellers, found throughout the oceans from abyssal plains to inshore shelf waters, estuaries, and lagoons. The biogeography and habitat preference of pilargids is poorly known and especially within the Australasian region there is lack of published records on the group, even though pilargids are regularly collected in benthic samples. In this study we have iden- tified over 500 lots of pilargids from four separate bioregions in northern Australia. We analyse the taxonomic data against site, depth, and sediment type. Preliminary results show that the pilargid fauna of northern Australia comprises 13 species in seven genera (Ancistrosyllis, Cabira, Litocorsa, Loandalia, Pilargis, Sigambra, and Synelmis). Although all four regions have a similar diversity of species (6–7 species each), the species composition differs between each region. In general, the pilargid fauna could be partitioned into two components: an offshore, fine sediment component characteristic of the Arafura and Carpentaria regions, and an inshore, sandy sediment/seagrass com- ponent characteristic of the Groote and Pellew regions. Two species, Cabira sp. 1 and Sigambra cf. tentaculata appear to be generalists occurring in both biotypes. The pilargid species composition in northern Australia is also compared to neighbouring Indo-West Pacific regions.

Presenter (*) 150 Poster Abstracts

Inermonephtys n. sp. (Polychaeta: Nephtyidae) from SE Brazil, with comments on the known species of the genus

Martin, Daniel,1* João Gil1 & Paulo da Cunha Lana2

1 Centre d’Estudis Avancats de Blanes (CSIC), Blanes, Girona, Spain 2 Universidade Federal do Paraná, Centro de Estudos do Mar, Pontal do Sul, Brazil

The genus Inermonephtys (Polychaeta, Nephtyidae) was first reported for the SW Atlantic by Lana (1986). He referred a number of specimens collected on the continental shelf off São Paulo and Paraná States (SE Brazil) to I. palpata Paxton, 1974, based upon the presence of lateral bifid anten- nae (antenas laterais bifidas, page 142) and barred pre-acicular chaetae with rows of denticles. This identification was erroneous and access to the type material of I. palpata Paxton, 1974, enabled the re-examination of both taxa. As a consequence, the original description of I. palpata is complement- ed with new data and iconography, and the Brazilian material is described as Inermonephtys n. sp.

In addition to I. palpata, the new species is compared with the other five known species of the genus, based on a selection of morphological characters extracted from the original descriptions. Inermonephtys n. sp. is thus characterized by inter-ramal branchiae starting from chaetiger three and basal papillae starting on chaetiger six, as well as by having two kinds of lyrate chaetae. Lyrate chaetae occur in very small numbers as a post-acicular bundle both in noto- and neuropodia all along the body. The arms of a given lyrate chaeta are always similar in length, varying from very short to very long. The later are the most common, while the former are more difficult to distin- guish and may be absent in some parapodia.

REFERENCES Lana, P C (1986) Nerítica 1(1), 135:54 Paxton, H (1974) Rec. Aust. Mus. 29(7): 197–208

Presenter (*) 151 Poster Abstracts

Temporal evolution (1981–2001) of a polychaete community

Marzialetti S.*, L. Nicoletti & G.D. Ardizzone

Università degli Studi di Camerino, Camerino, Italy

Aim: The development of an artificial reef’s polychaete community has been studied since its first settlement in order to examine long-term community dynamics and verify increase in biodiversity.

Location: Fregene, Tyrrhenian Sea. The reef was placed in 1981 at 12–14m depth on a sand-silty bottom in, 9 km north of the outlet of the Tiber River (Latium, Italy).

Methods: Benthic samplings were carried out from May 1981 to December 2001. At each sampling, two standard surfaces of 400 cm2 were scraped from the vertical walls of the same block. Temporal changes and main steps of the temporal evolution of the polychaete community were detected by computing univariate (S, N, d, H’) and multivariate (cluster, MDS) analysis of faunal data.

Results: Changes in the community structure were detected by increasing trends in the total number of species, individuals and values of the richness index (d) and the diversity index (H’). Cluster and MDS analyses showed that the 20 years development of the polychaete community is divided into different phases characterized by different benthic assemblages. Four groups of data stand out: the first one corresponds to the pioneer species settlement period (1981–82); the second one to a phase of mussel dominance and regression on the barrier (1983–85); the third one to a phase of mud accu- mulation between dead balanids, with limited presence of bryozoans (1991–92) and the last one corresponds to the data collected in 2001, a bryozoan’s bioconstruction dominance phase.

Conclusions: The increase in volume and heterogeneity of substrata can explain the increase in the total number of species and individuals and the different composition of the polychaete community of the artificial reef. The data collected support the hypothesis that the assemblage may not have reached steady-state equilibrium.

Presenter (*) 152 Poster Abstracts

The ontogeny of parapodia and setae in Laeonereis culveri (Nereididae)

Mazurkiewicz, Michael

University of Southern Maine, Portland, Maine, USA

A study on the development of parapodia and setae in Laeonereis culveri has disclosed marked differ- ences in the morphology of these taxonomically important structures between larvae, postlarval juve- niles, and adults. These differences result from alterations in the forms of the ligules and successional replacements of setae during the course of ontogeny. Further, it has been revealed that the posterodor- sal tentacular cirri originate from medial notopodial ligules of the first pair of larval parapodia.

Presenter (*) 153 Poster Abstracts

Prediction of the potential distribution of Magelona species in the German Bight (North Sea): a modelling approach

Meissner, Karin

Forschungsinstitut Senckenberg DZMB, Hamburg, Germany

The distribution of three Magelona species (M. filiformis, M. alleni, and M. johnstoni) was mod- elled for the southern part of the German Bight from abiotic parameters. Species distribution data used for analysis were abundance data converted to presence/absence data. Statistical modelling techniques, namely generalized linear models (GLM) and multivariate adaptive regression splines (MARS), were used to investigate responses of the three species to the environmental parameters silt content, grain size, organic content, water depth and salinity. Models were fitted individually for each species. Model evaluation was by bootstrapping method (the 0.632+ bootstrap) or, alternative- ly, cross-validation (100 fold). The area under the receiver operating characteristic (ROC) curve was used to evaluate the model’s ability to discriminate between presence and absence sites. Based on the best resulting models maps showing predicted probability of species occurrence in parts of the German Bight were generated. Results are discussed in regard to aspects of the autecology of the different species.

Presenter (*) 154 Poster Abstracts

A review of the cosmopolitan polychaete genus Aurospio Maciolek, 1981 including a new Antarctic species and evidence for ecological and evolutionary links between the shelf and deep sea

Mincks, Sarah L.,1* Adrian G. Glover2 & Craig R. Smith3

1 University of Alaska, Fairbanks, Alaska, USA 2 The Natural History Museum, London, UK 3 University of Hawai’i at Manoa, Honolulu, Hawai’I, USA

Recent concern over potential effects of climate change and concomitant loss of sea ice on high-lat- itude marine communities has stimulated an increasing amount of biodiversity research on polar continental shelves. Such efforts are complicated by the large number of new, undescribed taxa in these areas, such that spatial comparisons of communities at the species level are difficult. The soft- sediment macrofaunal community is poorly known, yet abundances, particularly of the polychaetes, are extremely high. Improved taxonomic and basic ecological information for key species is needed to predict climate change impacts. Here we present the first description of a highly abundant infau- nal polychaete from the West Antarctic Peninsula shelf, Aurospio sp. nov., with observations on its ecology, and evidence of wide-spread distribution on the shelf. This species is morphologically very similar to the cosmopolitan species Aurospio dibranchiata Maciolek 1981, yet slightly contradicts the original generic description. We thus present a revision of the genus based on morphological data, and construct a phylogenetic tree based on analysis of all available 16S and 18S rRNA gene sequences for Spionidae. Interestingly, while the new species alone was found at stations along the West Antarctic Peninsula shelf (500–650 m depth), a transition was observed along shelf-slope tran- sects in the Weddell Sea, with Aurospio sp. nov. abundant at shallower station (< ~2000 m), and replaced at deeper slope and abyssal depths by the congeneric A. dibranchiata, which is thought to be cosmopolitan. We use molecular phylogenetic data to explore long-standing questions regarding the potential relationships between polar shelf and deep-sea taxa.

Presenter (*) 155 Poster Abstracts

Modifications in corallum morphology of black corals in the presence of symbiotic polychaetes

Molodtsova, T. & Nataliya Budaeva*

P.P. Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia

Antipatharians or black corals (Anthozoa: Cnidaria) are a characteristic component of seamount suspension-feeding fauna and they often host abundant associated fauna. Important taxonomic fea- tures in this group are the size and the structure of polyps and morphology of chitinous skeletal axis, including the mode of branching and/or pinnulation and the skeletal spine morphology. We examined antipatharians from oceanic rises of the Indo-Pacific region with a similar brush-like growth form that were hosts to symbiotic polychaetes. Three species of polychaetes were present in the collection: Benhamipolynoe antipathicola (Benham, 1927) (Polynoidae) and Eunice marianae Hartmann-Schröder, 1998, and E. kristiani Hartmann-Schröder, 1998 (Eunicidae). Several species of black corals representing families Myriopathidae and Antipathidae can attain a similar brush-like colony growth form in the presence of same species of symbiotic polychaete. Morphology of the skeletal spines is also influenced. [Supported by RFFI grant 06-04-48764a.]

Presenter (*) 156 Poster Abstracts

Bathymetric gradient of benthic polychaete richness from the southeastern Pacific coast of Chile

Moreno, Rodrigo A.1*, Marcelo M. Rivadeneira2, Nicolas Rozbaczylo3, Franklin D. Carrasco4 & Elie Poulin1

1 Universidad de Chile, Santiago, Chile 2 University of California, San Diego, La Jolla, California, USA 3 Pontificia Universidad Católica de Chile, Santiago, Chile 4 Universidad de Concepción, Concepción, Chile

The bathymetric gradient of species richness for benthic polychaetes was evaluated along the south- eastern Pacific coast of Chile, from the intertidal to the abyssal zone (0–4,700 m depth). Three pos- sible hypotheses were tested to explain the shape of richness gradient established with 498 species: (a) Rapoport’s effect, (b) mid-domain effect (MDE), and (c) the source-sink hypothesis. Rapoport’s effect was evaluated by examining the relationships between the median bathymetric range and depth, and MDE was tested with a Monte Carlo simulation. The source-sink hypothesis was tested through a nested analysis. The species richness showed an exponential and significant decline across the bathymetric gradient. This pattern was characterized by a strong presence of short-range species in the shelf area, while the few species reaching abyssal depths tended to show extremely wide bathymetric ranges. The simulation analyses showed that the pattern is generally robust to sampling artifacts. This pattern cannot be reproduced by the MDE, which predicts a parabolic gradi- ent of richness. Rather, results are in agreement with predictions of Rapoport’s effect. In addition, the dataset is significantly nested at species, genus, and family level, supporting the source-sink hypothesis. The sharp exponential decline in benthic polychaete richness across the bathymetric gradient supports the general idea that abyssal environments should harbor fewer species than shal- lower zones. This pattern may be the result of a colonization-extinction dynamic, characterized by abyssal assemblages acting as “sinks” maintained mainly by shallower “sources.” The predictions of the source-sink hypothesis were also translated in bathymetric ranges of distribution that conform to Rapoport’s effect. The source-sink hypothesis provides a conceptual and methodological frame- work that may shed light on the search of general patterns of diversity across large spatial scales. [Acknowledgments: Institute of Ecology and Biodiversity, ICM P05-002].

Presenter (*) 157 Poster Abstracts

Are there two species identifiable as Magelona alleni Wilson, 1958, in north European waters?

Mortimer, K.* & A.S.Y. Mackie

National Museum Wales, Cardiff, Wales, UK

Magelona alleni is a distinctive species, with a robust body form and dimorphic abdominal lamel- lae. The notopodial lamellae are large and foliaceous, the neuropodial lamellae short and subtrian- gular. These features easily separate the species from all other European species. However, the tubes of specimens from different locations vary from mucous sheaths to papyraceous sleeves. The original description makes no mention of a tube. We investigate variations in the morphological characters of the animals and their habitat to determine the significance (or otherwise) of the observed differences in tube structure.

Presenter (*) 158 Poster Abstracts

Polychaete biodiversity and community structure on the West Antarctic Peninsula continental shelf

Nealova, L., S.L. Mincks,1* C.R. Smith2 & A.G. Glover3

1 University of Alaska, Fairbanks, Alaska, USA 2 University of Hawai’i at Manoa, Honolulu, Hawai’I, USA 3 The Natural History Museum, London, UK

The muddy sediments of the West Antarctic Peninsula continental shelf provide a rich macrofaunal habitat that can support up to 20,000 individuals per square meter when collected using small 300- or 500-µm mesh sieve sizes. Very few previous Antarctic studies have analyzed the biodiversity and community structure of this sediment community, since the majority of sampling on the WAP shelf, Ross Sea, and Weddell Sea has been undertaken using trawls and sledges with larger mesh sizes. As part of the FOODBANCS project investigating the fate of the summer phytoplankton bloom on WAP shelf sediments, we have investigated biodiversity and community structure of this small polychaete size-fraction from a series of megacore samples along a transect crossing the shelf. A significant shift in community structure was detected with distance from the shelf break, and com- positional similarities to deep-sea sites are investigated to test the hypothesis of deep-sea emergence on the Antarctic shelf.

Presenter (*) 159 Poster Abstracts

Fauveliopsidae Hartman, 1971 and Opheliidae Malmgren, 1867 (Annelida: Polychaeta) from the abyssal SE Atlantic Ocean

Nebel, Christian, Daniel Thiel, Markus Böggemann* & Günter Purschke

University of Osnabrück, Osnabruck, Germany

During two DIVA expeditions (Latitudinal Gradients of Deep-Sea BioDIVersity in the Atlantic Ocean) on board the R/V Meteor in 2000 and 2005, specimens inhabiting deep-sea soft bottoms from the southeastern Atlantic Ocean were collected. Samples were taken with epibenthic sledge, box corer (50 ? 50 cm) and multicorer (12 cores of 10 cm diameter), in a depth range from 5022–5672 m. The investigated Cape, Angola, and Guinea Basins are large and homogeneously structured deep-sea basins, which are separated from each other by the Walvis Ridge and the Guinea rise. The general objective of DIVA is to gain a more complete understanding of the benthic organisms and their relationship within these abyssal plains. Furthermore, zoogeographic patterns of single species and examination of speciation with morphological and molecular methods are neces- sary for a better understanding of historical causes and actual ecological factors regulating biodiver- sity. The present study reports on the Fauveliopsidae and Opheliidae in these DIVA collections. Specimens were studied with light and scanning electron microscopy, measured, described, and illustrated in detail. Additionally, molecular data will be used for widely distributed species to eluci- date if they are in fact cosmopolites or only complexes of cryptic or sibling species.

Presenter (*) 160 Poster Abstracts

Three new species of serpulids (Polychaeta: Serpulidae) from Brazil

Nogueira, João Miguel de Matos* & Adriano Abbud

Universidade de São Paulo, São Paulo, Brazil

Three new species of serpulids were found among the material collected by the project REVIZEE/Southern Score/Bentos Marinho, one belonging to Filogranula Langerhans, 1884, the second to Pseudovermilia Bush, 1907, and the third to Vermiliopsis Saint-Joseph, 1894. Of those, Vermiliopsis n. sp. and Filogranula n. sp. (as Omphalopoma sp.) had already been described, but not named, by Zibrowius (1970). The project REVIZEE studied the biodiversity on the Economic Exclusive Zone off the Brazilian coast. It was divided into four areas and we received the material from the southern area, which extends from Cabo de São Tomé, in the State of Rio de Janeiro, to Arroio do Chuí, in the State of Rio Grande do Sul, collected at depths between 50 and 650 m. Filogranula n. sp. has an operculum with a sunken funnel and a slender, sharp spine. It is similar to Filogranula sp. A, from the Gulf of Mexico, but they differ in the extension of thoracic membrane and morphology of chaetae and uncini. Pseudovermilia n. sp. has an operculum with a white, fleshy bulb and horn cap divided into 4–26 annuli, transparent and iridescent to light brown. It is closer to P. conchata ten Hove 1975, P. fuscostriata ten Hove, 1975, and P. holcopleura ten Hove, 1975, but differs from all these species in the morphology of the tube. Vermiliopsis n. sp. is characterized by the operculum with 1–7 flat, concave annuli, progressively shorter towards the tip. It is similar to V. annulata (Schmarda, 1861), but differs from it in the morphology of the operculum.

Presenter (*) 161 Poster Abstracts

A new species of Trypanosyllis Claparède, 1864 (Polychaeta: Syllidae) from southeastern Brazil, together with a redescription of Brazilian material of Trypanosyllis zebra (Grube, 1860)

Nogueira, João Miguel de Matos* & Marcelo Veronesi Fukuda

Universidade de São Paulo, São Paulo, Brazil

A new species of Trypanosyllis was found in a collection of polychaetes living in algae, sponges, sabellariid reefs, and similar substrates in the intertidal zone of a rocky shore at Praia do Guaraú, State of São Paulo, southeastern Brazil, in one of the collections of the project Biodiversity of Polychaetes on Rocky Shores along the State of São Paulo. This new species is herein described, together with a full description of Brazilian specimens of T. zebra (Grube, 1860), a cosmopolitan species which is common in nearby rocky shores along the State of São Paulo. Material was exam- ined alive under a stereomicroscope, relaxed in a menthol solution, fixed in 4% formaldehyde, then washed and stored in 70% ethanol. The specimens were studied under a stereomicroscope, light microscope, and SEM. Trypanosyllis n. sp. is characterized by an orange body in life, with dark red antennae and cirri throughout, more conspicuous on longer dorsal cirri along the body; parapodia throughout with thick, distally sharp, protruding aciculae, 2–3 on each anterior parapodium, 2 on midbody parapodia and 1–2 posteriorly; falcigers with short, sub-bidentate blades; pharynx long, extending for 10–11 segments, with 10 rounded papillae anteriorly and trepan with 10 small, trian- gular teeth; proventricle extending for 7–8 segments, with around 28 rows of muscle cells. Trypanosyllis n. sp. is compared with the most similar congeners.

Presenter (*) 162 Poster Abstracts

Identifying new polychaetes in Scandinavian waters with the barcode gene COI

Nygren, Arne,1* Fredrik Pleijel2 & Erika Norlinder2

1 Göteborg University/Zoological Institution, Systematics and Biodiversity, Göteborg, Sweden 2 Göteborg University, Tjarno Marine Biological laboratory, Strömstad, Sweden

There are about 650 known species of polychaetes in Scandinavian waters. We think this is an underestimate. We present a number of cases in which we have used the mitochondrial gene COI in order to to identify new polychaetes for the Scandinavian fauna.

Presenter (*) 163 Poster Abstracts

SPI-Scan: Affordable Sediment Profile Imagery

Paavo, Brian L.

Benthic Science Limited, Ohaupo, Waikato, New Zealand

Preliminary work on in-situ sediment profile imaging (SPI) has produced an instrument for gather- ing soft-sediment reconnaissance and habitat mapping data. Work has progressed through successful laboratory trials and advanced to production of a robust field device, SPI-Scan, now undergoing sea trials in water depths of 2–30 m. Commercial systems currently available are expensive (>US$25,000) and often require a large vessel (15 m) for deployment. This new device, constructed of inexpensive materials, returns digital imagery of the sediment/water interface comparable to the well-known REMOTS system. The device can be deployed from a small vessel by two persons and is intended to suit the needs of estuarine and nearshore researchers, municipalities, port authorities, and aquaculture concerns to cost-effectively evaluate soft-sediment habitats. Several environmental parameters such as grain size, visible redox depth, small-scale relief, and biological activity can be assessed during image analysis regardless of water clarity. If visibility permits, a benthic surface image of approximately 0.25 m2 is also obtained adjacent to the vertical profile image. As an instru- mentation platform, the device offers modification options for extended monitoring of the sediment- water interface, aiding studies of bioturbation and geochemistry. Combining these capabilities cre- ates an efficient tool for ground-truthing high-frequency sidescan sonar data. A GPS interface geo- references field-captured images for immediate integration into Geographic Information Systems (GIS). Dredge spoil disposal, sedimentation, organic loading, biological succession, and disaster response monitoring situations can be sampled extensively and repetitively without the delays incurred in grab sample retrieval and analysis while operation in time-lapse mode provides a glimpse of benthic activity over several tidal cycles in calm conditions.

Presenter (*) 164 Poster Abstracts

Antarctic macroalgae: a harbor for a rich macroinvertebrate community

Pabis, Krzysztof* & Jacek Sicinski

University of Lodz, Lodz, Poland

Dispersal mechanisms of benthic marine fauna is a highly interesting (still not sufficiently recog- nized) phenomenon in marine biology. Detached benthic macroalgae drifting with ocean currents may be an important factor for dispersion of shelf invertebrates. The circumcontinental Antarctic current should be certainly taken into account as a potential mechanism for circumantarctic disper- sion of the Antarctic marine shelf bottom fauna. Some detached large benthic brown algae, Desmarestia spp., Durvillea antarctica and Macrocystis pyrifera, are known to be common drifting species in the Southern Ocean. The very rich kelp canopy has been found in the Admiralty Bay (King George Island, South Shetlands) shallow sublittoral. The brown alga Himantothallus grandi- folius (occurring in the Maritime as well as in the East Antarctic seas) has been recognized as one of the most abundant in the phytal zone. Its voluminous holdfast, with a complicated, three-dimen- sional labyrinth, forms a sheltered harbor for a rich and diverse assemblage of invertebrate fauna. Polychaetes and amphipod and isopod crustaceans are the most diverse and abundant taxa. Other frequent, but not so numerous and diverse groups are: Bivalvia, Nemertini, and Nematoda. Polychaetes have been analyzed in detail. Over 80 species (4000 individuals) have been identified in the collection, found in 25 holdfasts taken from the depth range 10–60m. The most frequent and abundant species are Brania rhopalophora, Neanthes kerguelensis, Rhodine intermedia, Exogone heterosetosa, and Oriopsis alata, followed by frequent but not so abundant species Capitella capita- ta, Scoloplos marginatus, and Polycirrus kerguelensis. The structure of the H. grandifolius holdfast community differs clearly from other bottom polychaete assemblages.

Presenter (*) 165 Poster Abstracts

Taxonomic verification of Perinereis aibuhitensis (Grube, 1878) (Polychaeta: Nereididae) living in the Northwest Pacific Ocean

Park, Tae Seo*, Hyun Soo Rho & Won Kim

Seoul National University, Seoul, South Korea

Nereis (Neanthes) linea Treadwell, 1936, and N. (N.) orientalis Treadwell, 1936, described from China were synonymized with Perinereis aibuhitensis (Grube, 1878) by Hartman (1938). P. vancau- rica tetradentata Imajima, 1972 from Japan and Korea also has been synonymized with P. aibuhitensis by Lee et al. (1991). The taxonomical problem was that P. aibuhitensis has wide mor- phological variation in the number and arrangement of paragnaths. We reexamined the important taxonomic key character of paragnathspresented based on the four type specimens of N. (N.) linea, N. (N.) orientalis, P. vancauricanot tetradentata , and P. aibuhitensis. Moreover, we compared the molecular characteristics of the genetic divergences of mitochondrial cytochrome c oxidase subunit I (mt COI) gene among populations of P. aibuhitensis collected from Korea, Japan, China, and Taiwan. The result of both analyses show that two distinctly separated species exist in the Northwest Pacific Ocean: P. linea (Treadwell, 1936) from Korea, Japan and China, and P. aibuhitensis from Taiwan.

Presenter (*) 166 Poster Abstracts

Short-term variation of polychaetes in the nearshore zone of Admiralty Bay (Antarctica)

Petti, Monica A. V.*, Gabriel S. C. Monteiro, Edmundo F. Nonato, Rodrigo S. P. Skowronski & Thaïs N. Corbisier

Universidade de São Paulo, São Paulo, Brazil

Admiralty Bay (King George Island) is an Antarctic Specially Managed Area (ASMA). The present work is part of an integrated investigation of the benthic system of the bay and aims to study the short-term variability of polychaetes from the meio- and macrofauna community, in front of the Brazilian Antarctic Station, from the beginning to the middle of the austral summer, when the human activities increase. Sediment cores were taken by divers at two depths (5 and 15 m) weekly, from December 8, 1997, to January 3, 1998. Sediment characteristics and microphytobenthos were also evaluated during the five weeks. Around 3000 specimens of polychaetes were recorded. Apistobranchus glacierae Hartman, 1978, accounted for more than 80% of the total and was found mainly at 15 m depth. The density ranged from 3.0±2.2 to 6.2±3.7 ind/4.9 cm2 at 5 m depth and from 39.8±9.4 to 187.2±97.7 ind/4.9 cm2 at 15 m depth. Significant temporal differences were found only at 15 m depth, where the polychaete density was positively associated with the sandy fraction of the sediment and the total meiofauna density, a potential source of food for this group. The correlation analysis did not demonstrate any direct relationship between the polychaete density and microphytobenthic biomass, probably because it was not a limiting factor at these depths. The study of the short-term variability of the polychaete community has revealed an important step in the knowledge of Antarctic benthic ecology, mainly for the recruitment and growing at the first ben- thic stages, and the colonization process of disturbed areas.

Presenter (*) 167 Poster Abstracts

Copper toxicity to the polychaete Hydroides elegans: sensitivity among life stages and effects of environmental factors

Qiu, Jian-Wen

Hong Kong Baptist University, Hong Kong, P.R. China

Copper is a common toxicant in coastal areas. Copper toxicity varies with species and the develop- mental stages of a species. It is also influenced by a variety of environmental parameters including particulate matter and dissolved organic matter (DOM). In this study, we examined the sensitivity of different stages of H. elegans to copper stress, and quantified the influence of algae (a type of par- ticulate matter) and fulvic acid (FA, one of the major components of DOM) on the toxicity of cop- per to H. elegans larvae. The EC50 value for the development from oocyte to 2-cell, 2-cell to blas- tula, blastula to trochophore, and trochophore to juvenile was 47, 50, 71 and 29 mg Cu l–1, respec- tively, indicating the early development of this species is very sensitive to copper. The adults, how- ever, are very resistant to copper, with no mortality when exposed to ≤500 mg Cu l–1 for 48 hours. When algae (Isochrysis galbana) was included in the exposure solution, the toxicity, expressed as percentage of abnormal larvae caused by total copper, declined with increasing algal concentration, with 48-h EC50 (mean ± S.E.) ranging from 58.4 ± 4.5 mg l–1 in the controls to 121.9 ± 9.9 mg l–1 in the 106 cells ml–1 algal treatment. When percentage of abnormal larvae was modeled as a function of aqueous copper concentration, the 48-h EC50 was 64.9 ± 4.8 mg Cu l–1, irrespective of algal con- centration. When FA was included in the exposure medium and the data were expressed as a func- tion of total copper concentration causing abnormal development, the toxicity was dependent on FA concentration, with a 48-h EC50 ranging from 55.6 mg Cu l–1 in the no-FA control to 137.4 mg Cu l–1 in the 20 mg l–1 FA treatment. However, when expressed as labile copper concentration, the toxic- ity was independent of FA concentration and could be modeled as a logistic function, with a 48-h EC50 of 58.9 mg Cu l–1. Thus, algae and FA were protective against copper toxicity to the larvae, and such effects were caused by the reduction in labile copper due to complexation between algae and copper or FA and copper. Our results highlight the dependency of copper toxicity on the labile copper in this polychaete and the importance of considering binding by algae and organic matter in larval toxicological tests.

Presenter (*) 168 Poster Abstracts

Laonice (Annelida: Spionidae) from South America: an identification key and description of a new species

Radashevsky, V.I.1* & P.C. Lana2

1 Institute of Marine Biology, Russian Academy of Sciences, Vladivostok, Russia 2 Universidade Federal do Paraná, Centro de Estudos do Mar, Pontal do Sul, Brazil

Laonice species from South America are revised based on museum material and new collections made in Brazil. An identification key is provided to five species including Laonice antarcticae Hartman, 1953, Laonice weddellia Hartman, 1978, Laonice branchiata Nonato, Bolívar & Lana, 1986, Laonice sp., and a new species which is here described and illustrated. Earlier records of Laonice cirrata are referred to either L. branchiata or a new species.

Presenter (*) 169 Poster Abstracts

Undescribed diversity in the genus Polygordius: Pygidial glands as a useful taxonomic character

Ramey, Patricia A.1* & Dieter Fiege2

1 Rutgers University, New Brunswick, New Jersey, USA 2 Forschungsinstitut und Naturmuseum Senckenberg, Frankfurt, Germany

There has been renewed progress in documenting and understanding marine biodiversity on a glob- al scale. Members of the Polygordiidae are commonly found in all oceans in intertidal and shallow subtidal sandy sediments. They are relatively small, have indistinct external segmentation, and lack certain typical polychaete characters such as parapodia and chaetae. Characters previously used to distinguish species of the single genus Polygordius include body size, number of segments, color, shape of pygidium, ciliation on the body surface, and pattern of the circulatory system. While com- paring species of Polygordius for the description of Polygordius jouinae Ramey, Fiege & Leander, 2006, from the inner continental shelf off New Jersey, USA, the shape of the pygidium and associ- ated structures such as pygidial glands and anal lobes proved useful taxonomic characters. A general biogeographic overview of the diversity of pygidial morphology is presented, focusing on the num- ber, shape and orientation of the glands using SEM images. To date, 16 species and two subspecies are known for Polygordius. It appears, however, that several more species remain to be described. Thus, the view that the Polygordiidae represent a relatively small, homogeneous group (uniformity in morphological features) appears unfounded and diversity is greater than previously thought. Re- evaluation of morphological characters using morphological and molecular techniques will aid greatly in distinguishing among species so they can be accurately identified in ecological surveys, environmental assessments, and evolutionary analyses.

Presenter (*) 170 Poster Abstracts

Chaetopterus species in New Zealand‚ aliens or natives?

Read, Geoffrey B.* & Peter J. Smith

National Institute of Water & Atmospheric Research, Wellington, New Zealand

There is increasing evidence of worldwide diversity within Chaetopterus, a genus long-treated as monotypic. While investigations of Chaetopterus in New Zealand have a brief history, and no infau- nal species occur, at least one such species is long known and common on the shores of neighboring Australia. Now two subtidal epifaunal species have been found in New Zealand, one of which is possibly an alien invasive. This report backgrounds the occurrence of Chaetopterus in New Zealand and presents initial findings from a molecular and morphological study of the phylogeography of Chaetopterus, especially within the Pacific region.

Presenter (*) 171 Poster Abstracts

Studies on the biodiversity of terebellomorph polychaetes from hydrothermal vents in the Pacific and Atlantic Ocean

Michael Reuscher1,2, Dieter Fiege2, Thomas Wehe1,2 & Volker Storch1

1 Institut für Zoologie, Universität Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg, Germany 2 Forschungsinstitut Senckenbert, Sektion Marine Evertebraten II, Senckenberganlage 25, D-60325, Frankfurt/M, Germany

Considerable progress has been made in our knowledge of polychaetes from hydrothermal vents worldwide with about 100 species recorded for all families. However, as regards the Terebellomorpha data available are still insufficient, since only species from two out of five terebel- lomorph families have been recorded from hydrothermal vents so far, i.e. four species of Ampharetidae and eleven species of Alvinellidae, but no representative of the Pectinariidae, Terebellidae or Trichobranchidae. To gather further insight into the diversity and distribution of the hydrothermal vent fauna of terebellomorph polychaetes, samples collected during various cruises with RV Sonne and RV Meteor in the Pacific and Atlantic Ocean have been analyzed. A list of species for each hydrothermal vent locality is given and the zoogeographical relationships are dis- cussed.The aims of this study are to gain more information on the populations of Terebellomorpha from different vent localities worldwide, to identify and describe possible new species and to con- tribute to our understanding of the zoogeography of this group of polychaetes.

Presenter (*) 172 Poster Abstracts

Larval size in the Polydora cornuta complex (Polychaeta: Spionidae) is correlated with sperm availability in female seminal receptacles.

Rice Stanley A.* & Katherine A. Rice

University of Tampa, Tampa, Florida, USA

The tube-dwelling polychaete, Polydora cornuta, deposits egg capsules inside its tube that usually develop into three-chaetiger planktonic larvae measuring about 200 mm in length. Although adelphophagy (feeding upon unfertilized eggs within an egg capsule) has been reported in some populations of P. cornuta and in numerous other spionid polychaetes, the relationship between stored sperm in the female parent and the size of larvae within capsules has not been explored. We raised isolated female P. cornuta from two genetically and reproductively distinct populations (Florida and California) and determined percent fertilization and larval size in successive spawnings over time until the females ran out of stored sperm. As each female used up stored sperm during successive spawnings, the percent of fertilized eggs per capsule declined and larval size at release increased. In some cases, the largest larvae produced by an isolated female were 50% larger than the smallest larvae produced by the same female. Larvae inside capsules containing unfertilized eggs fed upon these eggs and grew larger than larvae that did not have unfertilized eggs to feed upon. Variable larval size produced by a single female worm (poecilogony) may therefore be a result of stored sperm limitations rather than a reproductive strategy.

Presenter (*) 173 Poster Abstracts

Benthic macrofauna of estuarine soft bottoms of the Baixada Santista (São Paulo, Brazil), with emphasis in polychaete annelids

Rizzo, Alexandra Elaine*, Silvia Maria Sartor & Paulo Ricardo Nucci

Museu de Zoologia, Universidade de São Paulo, São Paulo, Brazil

This study analyzed the macrofauna in an estuarine channel in the Baixada Santista region (São Paulo State, Brazil). Biotic and abiotic samples were taken at 40 stations along the channel, from 8 to 12 October 2006. The organisms were counted and identified in major taxonomic groups; the poly- chaetes were identified to the lowest possible taxonomic level. The volume of sediment was stan- dardized to the maximum capacity of the petit Ponar sampler (5 l). Of 19,347 animals collected, polychaete annelids dominated (11,115 ind., 57.45% of the total), followed by nematodes (2,883 ind., 14.9%), pericarid crustaceans (2,601 ind., 13.44%), bivalve mollusks (852 ind., 4.4%) and holothuri- ans (617 ind., 3.2%). Other groups contained less than 7% of the macrofauna community. Ten animal phyla were represented: Porifera, Cnidaria, Nemertea, Mollusca, Annelida, Sipuncula, Arthropoda, Nematoda, Echinodermata and Chordata. The polychaetes included 85 taxa, with 35 families repre- sented. Of these, 13 taxa were most frequent and/or abundant, comprising 83% of the total: Cirratulidae, Mediomastus sp. 1 and Mediomastus sp. 2, Protodorvillea sp., Glycinde multidens, Magelona sp., Kinbergonuphis orensanzi, Mooreonuphis lineata, Aricidea sp., Sigambra tentaculata, Polydora nuchalis, Sternaspis sp. and Trochochaeta sp. The highest richness, diversity and equitabil- ity were found at the stations nearest Santos Bay, where the pH, dissolved oxygen and salinity were also highest. The sediments at these locations contained a mixture of shell fragments and particulate organic material, providing a heterogeneous environment for establishment of the macrofauna.

Presenter (*) 174 Poster Abstracts

Nephtyidae (Annelida: Polychaeta) from São Paulo State, Brazil, including a new record for the Brazilian coast

Rizzo, Alexandra Elaine* & Antonia Cecília Zacagnini Amaral

Universidade Estadual de Campinas, São Paulo, Brazil

Until now, about 14 species of Nephtyidae have been recorded off the coast of the state of São Paulo, Brazil. In this study, four species: Aglaophamus juvenalis (Kinberg 1866), Nephtys acrochaeta Hartman 1950, Nephtys californiensis Hartman 1938, and Nephtys squamosa Ehlers 1887, were found from the intertidal zone to the shallow sublittoral (<50 m) off São Paulo during the program Biota Fapesp Marine Benthos. Nephtys californiensis is a new record for the Brazilian coast. Keys to genera and species of Nephtyidae recorded on Brazil are given.

Presenter (*) 175 Poster Abstracts

Benthic community structure and its relation with physical-chemical sediment parameters in northern Baja California, México.

Rodríguez-Villanueva,Verónica*, Ricardo Martínez-Lara & Vinicio Macías-Zamora.

Universidad Autónoma de Baja California, Ensenada, Baja California, México

In August 1998 and July 2001, 93 benthic stations were sampled along a regional-scale area cover- ing 120 km off the northwestern coast of México. Samples were collected using a van Veen grab at depths ranging between 5.6 and 200 m. Environmental parameters measured were depth, tempera- ture, salinity, oxygen, sediment grain size <63 µm, organic carbon, PAHs, PCBs, DDTs, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn and Ag. Principal Components Analysis (PCA) applied to physical-chemical parameters indicated that the first and second axes together explained 54.8% of total variance for abiotic variables. Main contributors to axis I were copper, zinc, lead, and PAHs and to axis II, salin- ity, depth, and organic carbon. These parameters generally defined spatial distribution for remaining parameters indicating a gradient from shallow to deep areas. Polychaetous annelids dominated com- munity structure, constituting 53% of total benthic macrofauna. Diversity analysis through Shannon-Wiener (H’) index, indicated that 18% of the area studied had low diversity values sugges- tive of a stressed environment, characterized by homogeneous community structure and polychaete species considered as pollution tolerant. Bray-Curtis similarity analysis based on abundance and specific composition data for all benthic macroinvertebrates revealed a 20% similarity, indicative of high species richness. Non-Metric Multidimensional Scaling (NMDS) analysis separated and identi- fied one group of shallow stations situated closest to known point sources of wastewater discharge in the region. Canonical Correspondence Analysis corroborated that depth, lead, sediment grain size, and organic carbon had the greatest influence over spatial distribution trends for community structure of benthic macroinvertebrates.

Presenter (*) 176 Poster Abstracts

Reproduction and population dynamics of Perinereis cultrifera (Polychaeta: Neredidae) of the Atlantic coast of el Jadida, Morocco

Rouhi, A., J. Sif, P. Gillet*, C. Durou & A. Ferssiwi

Université Catholique de l’Ouest, Angers, France

The polychaete Perinereis cultrifera (Grube, 1840) is a common species along the Atlantic coast of El Jadida (Morocco). Field investigations on reproduction and population dynamics were carried out from November 2003 to October 2004. Monthly samples were taken in the intertidal zone at low tide. The reproduction of P. cultrifera is of an atokous type.The laying of eggs by the females takes place from late April until early May; they can contain up to 4,947 eggs. The algorithm EM (McLachlan & Krishnan, 1997) was used for the separation of the cohort. The annual average bio- mass of the population is B = 9.4 g/m2, with a production P = 21.5 g/m2 and a ratio P/B = 2.3

Presenter (*) 177 Poster Abstracts

The dwarf males of Osedax (Siboglinidae, Annelida)

Rouse, G.W.1*, K. Worsaae2, S.K. Goffredi3 & R.C.Vrijenhoek4

1 Scripps Institution of Oceanography, La Jolla, California, USA 2 Marine Biological Laboratory, University of Copenhagen, Helsingør, Denmark 3 California Institute of Technology, Psadena, California, USA 4 Monterey Bay Aquarium Research Institute, Moss Landing, California, USA

All Osedax spp. discovered to date in Monterey canyon show marked sexual dimorphism, unlike all other siboglinids. Osedax males are found living in the lumen of the gelatinous tubes inhabited by the much larger females. The males appear to be arrested larval forms and are filled with all stages of spermiogenesis, with mature sperm accumulating in an anterior duct that opens the surface of the head. We have studied the anatomy of the males using light, confocal laser scanning, and electron microscopy. Multi-stainings with phalloidin, dapi, and antisera directed against serotonin (5-HT), FMRF-amid, and acetylated alpha-tubulin were applied for the confocal investigations. Larval fea- tures appear to be the retention of an anterior ciliary ring (prototroch), two chaetae-bearing seg- ments posteriorly, a simple net of longitudinal muscles, a typical annelid larval nervous system with an apical ganglion and the presence of yolk. The sperm structure is very similar to that of other siboglinids such as Riftia and Siboglinum, but there is no evidence of sperm being packaged as spermatozeugmata, or in spermatophores. The chaetae are long-handled hooks with curved teeth that are opposed in some cases, as seen in other siboglinids. There is no sign of the development of a gut, or any features typically seen in females such as the four anterior palps.

Presenter (*) 178 Poster Abstracts

Revision of Hermenia Grube 1856 (Polychaeta: Polynoidae), re-establishment of H. nodosa (Treadwell, 1901) and a new species from the Grand Caribbean

Salazar-Silva, Patricia

El Colegio de la Frontera Sur (ECOSUR-Chetumal), Quintana Roo, México

As part of a major study of polynoids of the Grand Caribbean, including the Mexican Caribbean, numerous specimens of Hermenia verruculosa Grube 1856 from different sites were examined. Differences observed were not considered in the redescription of Hermenia and of H. verruculosa by Pettibone (1975). To study the importance of these differences, type material of Hermenia species were examined. Principal findings are the following: Hermenia Grube 1856 and its three species H. verruculosa, H. acantholepis (Grube, 1876) and H. neoverruculosa Pettibone, 1975, are redescribed; reestablishment of H. nodosa (Treadwell, 1901) is proposed; and specimens from the Grand Caribbean show enough differences to consider it as a new species. Features which distin- guish the species confused with H. verruculosa are body shape, projection of segment two on the prostomium, abundance and arrangement of tubercles on the dorsal part, and of papillae on the ven- tral part. The main conclusion is that the specimens examined of H. acantholepis, which is widely distributed in the Indo-Pacific Ocean, and H. neoverruculosa, distributed in the Indic, show differ- ences which require greater taxonomic eeffort in order to discard or corroborate them as complexes of confounded species. The specimens were examined with a stereo as well as a compound micro- scope; the species are described in a standardized manner, and diagnostic characteristics were illus- trated and a taxonomic key for all the species was written.

Presenter (*) 179 Poster Abstracts

Brazilian species of Sabellariidae (Sabellida): actual status and distribution

Santos, André Souza 1,2* Ana Claudia Brasil2 & Martin Lindsey Christofferssen1

1 Universidade Federal da Paraíba, Paraíba, Brazil. 2 Universidade Federal Fluminense, Rio de Janeiro, Brazil

Sabellariids live in sand tubes cemented onto rocky substrata, some species forming extensive reefs. Species of this family are diagnosed by the organization of the peduncular stalk and crown, number and kind of paleae, differences in geometry and ornamentation of the surface of the paleae, presence of nuchal hooks, presence or absence of mediun organ and its form and length, feeding tentacles, number and size of the buccal tentacles, organization of first and second thoracic segments, number of parathoracic segments, and the presence or absence of dorsal branchia in some segments. The diversity of morphology of the mediun organ and relation with the organization of the peduncular stalk and thoracic region was not compared before. The aim of this study is to contribute to knowl- edge of the sabellariids from the Brazilian coast, re-examine identified species and study populations that were not studied before. Eleven species were recorded for the Brazilian coast (Phragmatopoma caudata, P. lapidosa, P. virgini, Sabellaria bella, S. bellis, S. nanella, S. wilsoni, S. virgini and Gesaia lanai, but only six of these species are identified: P. caudata, P. lapidosa, Sabellaria bella, S. bellis, S. wilsoni and Gesaia lanai). Two other genera, Tetreres and Lygdamis, were found. The depth of these animals extended from 64 to 434 m. When comparing the peduncle of Sabellaria species a relationship was found: the closer the medium organ is to the opercular crown, the bigger it is. Furthermore, when these structures are close, the operculum becomes closed. Finally, when the above conditions occur, the feeding tentacles partially enclose the mediu organ.

Presenter (*) 180 Poster Abstracts

Nereididae from Rocas Atoll (Northeast Brazil)

Santos, Cinthya

Universidade Federal Fluminense, Rio de Janeiro, Brazil

The Rocas Atoll, Rio Grande do Norte State (RN), Brazil (03°51’30’’S and 33°49’29’’W) is a wildlife sanctuary, and in 2001 was designated by UNESCO as a World Heritage Site. The atoll consists mainly of coral and red algae. The coral ring is almost closed, with a 200-m wide channel on the north side and a much narrower channel on the west side. Seven species of nereidids belong- ing to the genera Nereis, Neanthes, Ceratocephale, Perinereis, and Ceratonereis were identified in the area. Among them is one new species of Nereis and three new records for the Brazilian coast: Nereis panamensis, Ceratonereis longicirrata and Perinereis floridana.

Presenter (*) 181 Poster Abstracts

Phylogenetic relationships within Gymnonereidinae (Nereididae, Polychaeta)

Santos, Cinthya1* & Paulo Lana2

1 Universidade Federal Fluminense, Rio de Janeiro, Brazil 2 Universidade Federal do Paraná, Centro de Estudos do Mar, Pontal do Sul, Brazil

A cladistic analysis of the Gymnonereidinae is presented. It was performed from 38 characters coded as multistate and 27 terminal taxa. Character information was based on examination of avail- able types, non-type material, and literature. The polarity was assessed by outgroup comparison with one hesionid species and four other nereidid species. The analysis yielded 2,640 equally parsi- monious trees, 62 steps long. The monophyly of Gymnonereidinae is supported and two clades were identified: Micronereides Day, 1963, with one species and Ceratocephale Malmgren, 1867, with 18 species. Micronereides includes small-bodied species, indicated by the absence of cir- rophores in the anterior cirri and along the body, absence of eyes and absence of transversal dorsal projections. Ceratocephale includes species with a cirrophore on anterior cirri, dorsal cirrophores along the body and the presence of dorsal transversal projections. Gymnonereis (Horst, 1919) and Tambalagamia Pillai, 1961, are junior synonyms of Ceratocephale. Pisionura Hartmann-Schröder, 1977, is a junior synonym of Micronereides. For improved precision in future descriptions of Gymnonereidinae, it is suggested that the terms “bifid ventral cirri” and “accessory dorsal cirri” should be replaced by “double ventral cirri” and “lateral projections of cirrophore.”

Presenter (*) 182 Poster Abstracts

Assessment of Polychaete faunal biomass in the northwestern Mediterranean coast

Sardá, Rafael*, Céline Labrune, Antoine Grémare, Jean Michel Amouroux, João Gil & Sergi Taboada

Centre d’Estudis Avancats de Blanes (CSIC), Blanes, Girona, Spain

Forty-four transects along the portion of coast between Valencia (Mediterranean coast of Spain) and the mouth of the Rhone River were sampled for sediment and polychaete fauna during September–October 1998 (REDIT-I campaign) and December 1999 (REDIT-II campaign). The polychaete fauna was analyzed to describe the distribution pattern of polychaete assemblages at this macro scale, namely littoral fine sands (LFS), littoral coarse sands (LCS) littoral sandy mud (LSM) and terrigenous coastal mud (TCM), and to know the pool of species present in this area at the stud- ied depths. Assemblages were tightly associated with depth and sediment granulometry as indicated by cluster analysis. Faunal samples were sieved on a 1-mm mesh and polychaete fauna was deter- mined at species level. Biomass data from the obtained collection have been assessed by species and by trophic guilds and is presented in this work. Comparisons will be made with previous data.

Presenter (*) 183 Poster Abstracts

Polychaetes from sperm whale-fall ecosystems in northwest Pacific

Sato-Okoshi, Waka*, Kenji Okoshi & Yoshihiro Fujiwara

Tohoku University, Sendai, Japan

This is the first study of the polychaetous fauna from sperm whale-fall ecosystems, based on mass sinking of whale carcasses at shelf depths in the northwest Pacific. Observations were conducted over a 2-year period on replicate sperm-whale carcasses implanted at depths of 219–254 m off the southern part of Japan from 2003 to 2005. The total number of polychaete families was similar among years (15–18), but the family identities varied markedly between the 1.5-year and later sam- pling times. Nereididae, Capitellidae and Dorvilleidae constituted more than 70% of the total col- lected polychaete abundance at 1.5-year carcasses. On the other hand, a protodrilid polychaete was obviously more abundant on the 2.5- and 3.5-year-old ones. Cirratulidae, Lumbrineridae, and Dorvilleidae constituted more than 80% of total polychaete abundance on the 2.5-year-old carcasses and more than 70% of total polychaetes on 3.5-year carcasses.

Presenter (*) 184 Poster Abstracts

Global distributional patterns of deep-sea polychaetes recently found in the deep Weddell and Scotia Seas

Schüller, Myriam* & Brigitte Ebbe

Forschungsinstitut Senckenberg, DZMB, Bonn, Germany

During the expeditions ANDEEP I-III, over 6,000 polychaete specimens from 13 families have been identified. The sampled depth ranges lay between 700 and 5500 m. Fifty-five formerly classified species were distinguished. Based on historical records, the global distribution patterns of these species were reconstructed. It became apparent that many polychaete species found have a far- spread distribution. Records from world-wide ocean basins and all depths were found. Thus the polychaete fauna of the deep Southern Ocean appears not as isolated as that of the shelf. A certain extent of eurybathy in addition seems to be a common trait in polychaetes. The distributional pat- terns of the Ampharetidae, Opheliidae, Scalibregmatidae, Sphaerodoridae, Syllidae and Terebellidae were analyzed in detail and distinct differences between the families were found. Possible explana- tions for the patterns were assumed in reproductive and life cycles of the families, their vagility and feeding strategies, and evolution.

Presenter (*) 185 Poster Abstracts

Comparative genetic analysis of contrasting developmental modes in Streblospio benedicti, a poecilogonous spionid polychaete

Schult, N.* & D. McHugh

Colgate University, Hamilton, New York, USA

The phenomenon of poecilogony, in which more than one type of larva is known within a single species, provides a wonderful opportunity to investigate the genetic architecture underlying differ- ences between planktotrophic and lecithotrophic larvae. We are studying larval development in the poecilogonous spionid polychaete, Streblospio benedicti, with the ultimate goal of using compara- tive gene expression data to inform our understanding of evolutionary changes in larval develop- mental modes of marine invertebrates. It has been hypothesized that different larval developmental modes may have evolved through changes in the timing of gene expression such that some traits (e.g., functional gut) develop earlier in feeding larvae compared to non-feeding larvae, while others develop earlier in yolk-dependent larvae. Alternatively, the levels or the sites of gene expression in the larval body may differ between them rather than the timing. Using a candidate gene approach in S. benedicti, we have cloned and sequenced two genes known to be involved in gut development, a Tbox6 ortholog and hedgehog, and are recording differences in expression levels throughout lecithotrophic development using quantitative PCR; the next step is to compare these results with those for planktotrophic development. We are also expanding the numbers of genes we are testing, and are undertaking in situ hybridization studies to determine whether shifts in sites of gene expres- sion differ between the two larval types during development.

Presenter (*) 186 Poster Abstracts

Phylogeny of the Opheliidae revisited

Sene-Silva, G.1, P.C. Lana1* & J.A. Blake2

1 Universidade Federal do Paraná, Centro de Estudos do Mar, Pontal do Sul, Brazil 2 ENSR Marine & Coastal Center, Woods Hole, Massachusetts, USA

This study evaluates the phylogenetic relationships and the taxonomic status of internal groups of the Opheliidae by means of a cladistic analysis which includes nine of the 10 genera currently recog- nized. A total of 77 species were analyzed: 65 opheliids, nine scalibregmatids, and two other species belonging to the families Arenicolidae and Capitellidae. Only Travisiinae of the three traditionally recognized subfamilies of Opheliidae is monophyletic, containing exclusively Travisia with epipodial lappets and absence of parapodia as synapomorphies. The Travisiinae are a sister-group of another clade made up of the remaining genera and defined by branchiae inserted dorsally to the notopodium and the presence of lateral and ventral furrows. The present analysis indicates that Lobochesis should be synonymized with Euzonus (as already suggested by other authors), making the latter mono- phyletic. Armandia and Polyophthalmus are also monophyletic. Ophelia is paraphyletic and contains an internal clade defined by the presence of lateral and ventral furrows along the whole body. This clade includes Ophelina (also paraphyletic), Ammotrypanella, Armandia, Polyophthalmus, and Tachytrypane. The results indicate that the current use of the traditional opheliid subfamilies is not adequate, since Opheliinae is not monophyletic if Ophelininae is considered valid. As such, the clas- sification of the opheliids needs to be amended to reflect its phylogenetic history.

Presenter (*) 187 Poster Abstracts

The polychaete type-collection at the Swedish Museum of Natural History

Sigvaldadottir, Elin

Swedish Museum of Natural History, Stockholm, Sweden

The Swedish Museum of Natural History has a large collection of polychaete types. The majority of the types were collected in the nineteenth century when Swedish researchers traveled all over the world in large expeditions. In a two-year project, the aim is to photograph and register all type material available in our collection. All information will be stored in a database and published on the Internet. In the poster I will give some information about this project and especially present two authors. Anders Johan Malmberg collected material mainly from the Arctic and the North Atlantic regions. In the collection we have more than 100 types described by Malmgren, many of them still valid. Johan Gustaf Kinberg described material mainly from the southern hemisphere collected in the Eugene-expedition 1851–53. In the collection we have over 250 types described by Kinberg.

Presenter (*) 188 Poster Abstracts

A new species of Pseudopolydora associated with molluscs in South Africa

Simon, Carol A.* & Martin H. Villet

Rhodes University, Grahamstown, South Africa

A new species of Pseudopolydora is described from the south coast of South Africa. This species was associated with the gastropods Haliotis midae and Scutellastra longicosta and the bivalve Perna perna, but it is unclear if it bores into the shell. The new species resembles Pseudopolydora gibbsi Light, 1974. In both species branchiae first appear on chaetiger 6, posterior chaetigers bear stout notopodial hooks, the modified spines of chaetiger 5 are arranged in a line and not a J-, U- or C-shaped double row that is characteristic of most species in this genus, and the posterior major spines of chaetiger 5 form falcate hooks. The new species differs from P. gibbsi in having an occip- ital tentacle, a bilobed prostomium, a greater number of branchiae (28 – 47 pairs compared to 10 –14 pairs), more hooded hooks per series (8–16 compared to 6 – 8) and hooded hooks first appear on chaetiger 9 (not 8, which is more common in Pseudopolydora). Relationships with other mem- bers of this genus will be discussed.

Presenter (*) 189 Poster Abstracts

Effects of the decline of Halodule wrightii meadows on polychaete associations in Paranaguá Bay (Southern Brazil)

Sordo, Laura N.* & P.C. Lana

Universidade Federal do Paraná, Centro de Estudos do Mar, Pontal do Sul, Brazil

There is growing evidence that seagrass meadows in Paranaguá Bay are presently experiencing a gradual decline, presumably because of the spreading of the epiphytic brown algae Hincksia sp. The high abundance of Hincksia at Rasa da Cotinga Island (treated as “contaminated site”) is having a shadowing effect on the meadow, whereas it is almost absent at the meadow located at Mel Island (treated as “control site”). This work compares faunal patterns at both sites and investigates the effects of seagrass decline on the abundance and diversity of associated polychaete fauna, based upon the benthic sampling carried out in December 2006 and May 2007. Most of the species found at both sites are mobile predators or burrowing detritus feeders, such as the numerical dominants Magelona nonatoi, Armandia hossfeldi and Lumbricalus januari. A preliminary analysis showed that, despite a continuing regressive trend of the seagrass meadow at Rasa da Cotinga Island, there were no significant differences in the abundance and species richness of polychaete associations between sampling sites or times, though Neanthes succinea and Aricidea albatrossae became more frequent recently. Despite the obvious regression of Rasa da Continga meadow, the polychaete asso- ciation has not responded yet to the change in the availability and biomass of Halodule wrightii.

Presenter (*) 190 Poster Abstracts

New proposals of homology of the parapodial lobes, hooks, and chaetae position for the taxon Eunicida (Polychaeta)

Steiner, Tatiana Menchini* & A. Cecilia Z. Amaral

Universidade Estadual de Campinas, São Paulo, Brazil

The two subfamilies within Onuphidae, Hyalinoeciinae and Onuphinae, possess synapomorphies related to the presence and kind of insertion of the setae and hooks on the parapodial lobes. Observation of details of these lobes and also of the position of the different setae and hooks revealed new elements to aid in the study of phylogenetic relationships among the genera of Onuphidae and among the families included in Eunicida. Species of the genera Diopatra, Paradiopatra, Mooreonuphis, Rhamphobrachium, Nothria, Anchinothria, Hyalinoecia, Lumbricalus, Arabella, and Dorvillea were examined. As a result, a new terminology for the para- podial lobes is proposed, and the homology of the structure of these lobes is traced in the different body regions of the Onuphidae and in the principal families of Eunicida. The neuropodium of the first parapodia of Nothria, Anchinothria, and Hyalinoecia (subfamily Hyalinoeciinae) and Rhamphobrachium (Onuphinae) undergo a 90-degree rotation, which does not occur in the other genera examined. Certain similarities were also noted in the form and position of the subacicular hook of both taxa, suggesting that Rhamphobrachium may be closer to the Hyalinoeciinae than the present classification indicates. The structure that in this study is termed the acicular lobe occurs only in the Onuphidae and Eunicidae; in the other families, an obvious pre-setal fold does not exist, corroborating the hypothesis that these two taxa may be more closely related to each other than to the remaining families.

Financial support: FAPESP (Programa Biota/Fapesp – O Instituto Virtual da Biodiversidade - www.biotasp.org.br) and CNPq.

Presenter (*) 191 Poster Abstracts

Re-evaluation of morphological characters used in the taxonomy of the genus Diopatra (Onuphidae, Polychaeta): new perspectives

Steiner, Tatiana Menchini* & A. Cecilia Z. Amaral

Universidade Estadual de Campinas, São Paulo, Brazil

The genus Diopatra has been studied by different workers, who attempted to define morphological characters that are relevant for species identification. Their attempts were hampered by the lack of characters of taxonomic value. This study examined in detail the abundance of external morphologi- cal structures possessed by the genus Diopatra, in order to gain new perspectives for taxonomic and phylogenetic studies. The characters of 410 specimens collected in Brazil were analyzed, including intraspecific variations and those of young forms. The influence of fixation on measurement of the structures was also analyzed for certain characters. A total of 113 characters, arranged in 25 groups, were analyzed. About 60 of the characters are new, and the rest are commonly used in species iden- tification. About 61 were efficient to define the nine different morphotypes found, and which cer- tainly correspond to nine different species. Twenty-nine characters did not show significant varia- tions in the specimens studied, 14 may not be relevant to the taxonomy of the genus, and nine can be used, although more detailed study will be necessary. Certain characters commonly used in pre- vious studies were shown to be inconsistent for determination of the morphotypes. For this genus, the study of morphology still provides good characters, which could also be used in phylogenetic studies. The characters analyzed could be used and/or readapted for other genera in the Onuphidae and other families in Eunicida. [Support: Biota/Fapesp and Revizee/MMA].

Presenter (*) 192 Poster Abstracts

Chemical ecology and biogeographical considerations of polychaetes from Bouvet Island and the eastern Weddell Sea (Antarctica)

Taboada, Sergi*, Katrin Iken & Conxita Avila

Centre d’Estudis Avancats de Blanes (CSIC), Blanes, Girona, Spain

Polychaetes are a very important component in Antarctic infaunal macrobenthic communities. They represent a highly diversified group of organisms and also contribute a high percentage to the abun- dance and biomass of the Antarctic soft-bottom communities. Marine chemical ecology in Antarctica has mainly focused so far on the groups of Porifera, echinoderms, and molluscs. No studies on the presence of ecologically relevant natural products in Antarctic polychaetes have been carried out to date. The interest of these previous works has focused on the chemistry of bromophe- nol related compounds in Thelepus extensus and T. cincinatus (Terebellida), and in mycosporine- like amino acids (MAAs) from Aglaophamus ornatus, Neanthes kerguelensis, Tomopteris carpen- teri (Phyllodocida) and an unidentified species. In the present study we provide for the first time chemical ecology information on selected species of Antarctic polychaetes. Laboratory experiments performed on organic extracts from Polyeunoa laevis and Aricia foetida demonstrated a significant feeding repellence of the latter against an omnivorous sympatric and common sea star predator of the Antarctic benthos, Odontaster validus. Moreover, chemotaxis of one species towards a gorgon- ian where it usually lives was tested using Y-maze experiments. All these chemical ecology experi- ments were directed to establish possible interspecific relationships mediated by natural products in these polychaetes. Furthermore, we are also presenting here a faunal list of the collected species in the frame of our ECOQUIM projects (“Chemical Ecology of Antarctic Benthic Invertebrates”), with some biogeographical considerations. Samples were obtained mainly from the eastern Weddell Sea, but also from Bouvet Island and nearby areas.

Presenter (*) 193 Poster Abstracts

Analysis of protein expression during regeneration in Lumbriculus variegatus

Tweeten, Kay* & Beth Mackenthun

College of St. Catherine, Saint Paul, Minnesota, USA

The proteomes of regenerating and non-regenerating tissues of Lumbriculus variegatus were com- pared to determine how patterns of protein expression changed during the regenerative process. Homogenates were made from non-regenerating tissue and from blastemas of anterior and posterior regenerating tissue at 24, 48, 72, 96, and 120 hours into regeneration. The extracted proteins were separated using two-dimensional gel electrophoresis. Gels were analyzed using Syngene Dymension 2 software. Differentially expressed proteins were analyzed by mass spectromtery to provide tenta- tive identification of proteins involved in regeneration of anterior and posterior structures in this freshwater oligochaete.

Presenter (*) 194 Poster Abstracts

Vertical distribution and trophic structure of polychaete assemblages in relation to particulate organic matter quality in sediments from the São Sebastião Channel, Brazil.

Venturini, Natalia1*, Ana Maria S. Pires-Vanin1, Adriana R. Perretti1, Elisabete de S. Braga1, Pablo Muniz2

1 Instituto Oceanográfico da Universidade de São Paulo, São Paulo, Brazil 2 Universidad de la República, Montevideo, Uruguay

The nutritional value of the organic material deposited in sediments of the São Sebastião Channel was assessed based on proteins (PRT), lipids (LPD), carbohydrates (CHO), and photosynthetic pig- ments. Changes in polychaete density, biomass, and relative abundance of trophic groups to varia- tions in organic matter composition were evaluated. CHO were the predominant class of organic polymers, followed by lipids and proteins. The biopolymeric carbon represented less than 40% of total organic carbon resulting in low values of the food index. In general, concentrations of bio- chemical markers were high at the surface and tended to decrease within the sediment column. Polychaete mean densities showed no significant differences among the sampling locations but high values were observed between 0 and 6 cm sediment depth. Mean biomass was significantly higher at station 6 than at stations 2, 3 and 5. Except at station 6, biomass values decreased in the deepest sediment layers. The relatively high phaeopigment and carbohydrate concentrations suggest the occurrence of aged and partially degraded organic matter, mainly, at stations 2, 3, 4 and 5. Surface deposit-feeding polychaetes showed high relative abundance at stations 2, 3 and 5, whereas, subsur- face deposit-feeders were more abundant at station 4. On the other hand, at stations 1 and 6 the high lipid content, LPD/CHO and PRT/CHO ratios indicate the presence of particulate organic matter of high quality potentially available for benthic organisms. Carnivorous polychaetes were more abun- dant at stations 1 and 6 but surface and subsurface deposit-feeders were also well represented.

Presenter (*) 195 Poster Abstracts

The ultrastructure of calcareous sabellid tubes

Vinn, Olev,1* Harry A. ten Hove2 & Harry Mutvei

1 University of Tartu, Tartu, Estonia 2 Zoologisch Museum Amsterdam, Amsterdam, Netherlands

Since its description in 1820, the calcareous tubes of the Jurassic/Cretaceous taxon Glomerula gor- dialis were regarded as belonging to a serpulid polychaete. Jäger (2004) compared their macroscop- ic morphology with those of the Recent sabellid genus Calcisabella, and synonymized both genera, at the same time transferring Glomerula to the Sabellidae. Based on a comparison of tube ultra- structure of Fossil and Recent material, we support this synonymy. Tube ultrastructure of serpulids differs from that of Glomerula, calcareous tubes probably evolved convergently within the Sabellida. The tube wall in Recent G. piloseta (formerly Calcisabella piloseta) is composed of sub- parallel lamellae of aragonitic irregular spherulitic prisms in the inner layer, and spherulites in the outer layer. These calcified lamellae are separated by organic films of different thickness. The struc- ture of the internal tube layer in G. piloseta, and the structure of entire wall in Fossil Glomerula is similar to the tube structure of Dodecaceria (Polychaeta, Cirratulidae). The irregular spherulitic prisms of Glomerula are similar to those found in the external layer of Hydroides dianthus and the internal layer of Spiraserpula caribensis (both Polychaeta, Serpulidae).

Presenter (*) 196 Poster Abstracts

Nervous system of free-living female and dwarf ectoparasite male Scolelepis laonicola comb. nov. Tzetlin, 1985 (Polychaeta, Spionidae)

Vortsepneva E.V.*, A. B. Tzetlin & E.B. Tsitrin

Moscow State University, Moscow, Russia

The nervous system of free-living female Scolelepis laonicola (Polychaeta, Spionidae) was studied with the help of routine histology and light microscopy. The complete reconstruction of the nerv- ous system of the dwarf ectoparasitic male attached to the dorsal side of female was done by immunohistochemical methods in combination with confocal laser scanning microscopy. The organ- ization of the central nervous system of the female follows the pattern already known for Spionidae. The central nervous system of the female consists of a cerebral ganglion, divided into two distinct symmetrical parts. Circumesophageal connectives are split into dorsal and ventral roots. The double nervous cord retains an intra-epidermal position. The nervous system of the ectoparasitic male is reduced. Distinct cerebral ganglia were not found. The circumesophageal connective is divided into dorsal and ventral roots. The ventral nerve cord has no segmental ganglia. In addition, two dorso- lateral and two ventral-lateral longitudinal nerves run along the body. Five pairs of segmental nerves arise from the VNC. The biggest segmental nerve, the parapodial one, goes from the VNC to the parapodia and ramifies into several small branches inside it. In the anterior part of the body of the male, the VNC turns 90º to the left. As a result, the reduced head of the parasitic male is situat- ed transverse to the longitudinal axis of the host female. While the adult males are attached to the female back and are not able to move, the well developed innervations of the parapodia are proba- bly evidence of an active free larval or post-larval stage of development.

Presenter (*) 197 Poster Abstracts

Reconstruction of the muscular system in dwarf ectoparaite male Scolelepis laonicola comb. nov. Tzetlin, 1985 (Polychaeta, Spionidae)

Vortsepneva, E.V.*, A.B. Tzetlin & E.B. Tsitrin

Moscow State University, Moscow, Russia

The muscle system of the dwarf ectoparasitic male of Scolelepis laonicola was reconstructed by Falloidin-TRITC technique and confocal scanning microscopy. The musculature of the body is well developed. Two ventro-lateral and two dorso-lateral longitudinal muscle bands, a median ventral muscle band, transverse muscles in the body wall, and finally oblique muscles are the main muscu- lature of the body of dwarf parasitic male of S. laoniclola. The intestine and ventral mesenteries also have some muscle fibers. In general, the musculature of the body wall of the S. laonicola male is quite similar to that described for another spionid, Prionospio. While the anterior part of the body of the male penetrates the female, all four main longitudinal muscle bands of the male body muscu- lature go inside the female. They are twisted to the right (about 180º). Oblique muscle fibers form a kind of basket-like structure, very similar to the peristomial ones in Prionospio. The well-developed musculature of the almost motionless parasitic males of S. laonicola, which are stationary and fixed on the body of the females, probably is evidence that the pre-settlement free-living juvenile males were active swimmers.

Presenter (*) 198 Poster Abstracts

Physico-chemical properties of polynoidin, the luminescent protein of scale worms

Vysokikh, Mikhail*, Maria V. Plyuscheva & Ilya V.Manukhov

A.N.Belozersky Phys.Chem.Biol.Institute, Moscow State University, Russia

The origin of the bioluminescence in polynoids is a photoprotein that reacts specifically to the pres- ence of reactive oxygen species (ROS) such as superoxide anions, but not to other ROS such as hydrogen peroxide. This membrane photoprotein was called polynoidin by Bassot et al. (1987). Two species of scale worms Harmothoe imbricata (“luminescent”) and Lepidonotus squamatus (“non-luminescent”), according to Nicol (1953) were collected in the White Sea, and two others Harmothoe areolata (“luminescent”) and Lepidonotus clava (“non-luminescent”) were collected in the Mediterranean Sea. All worms were kept alive in artificial sea water. Amino acid sequence and physico-chemical properties of purified proteins were determined and kinetic parameters for lumi- nescence and its Ca2+-dependence were measured. Surprisingly, just 22 N-terminal amino acids sequence, to 95%-identical for all studied proteins (MYAKIPLPFPTAASSYTYGINC), able to emit light in response of superoxide anion appearence. Further comparison of luminescence of the N-ter- minal peptide and not processed by limited proteolysis whole proteins revealed that in first case light emission does not depend on Ca2+ ions. At the same time, whole proteins did not demonstrate any luminescence in the presence of EGTA, a known Ca2+ chelator. Protein sequence shows that Ca2+ - binding site with 70% homology to related part of ryanodine receptor locating within C-ter- minal part of proteins. In C-terminal part main differences in sequence are located at clusters around Ca2+-binding site and within Œ±-helixes, forming hydrophobic core of the protein. Relation of difference in polynoidines sequences to their kinetic behaviour, structure and physiological impli- cation such as Ca2+ -sensitivity and ROS-specificity are discussed.

Presenter (*) 199 Poster Abstracts

Polydora and Dipolydora (Polychaeta: Spionidae) of estuaries and protected bays of subtropi- cal eastern Australia: a review and morphometric investigation of their taxonomy and distri- bution

Walker, Lexie M.

Southern Cross University, East Lismore, NSW, Australia

Polydorid taxonomy in Australia has not been reviewed for many years. Existing literature is biased toward the temperate fauna of south-eastern Australia. Currently the Australian polydorid fauna includes 49 taxa in the genera Polydora, Dipolydora, Pseudopolydora, Carazziella, Boccardia, Boccardiella and Polydorella. This study reviews the taxonomy and distribution of Polydora and Dipolydora (Polychaeta: Spionidae) from subtropical east coast estuaries and protected bays of Australia. The area of interest extends through four marine bioregions from Gladstone in Queensland (~24ºS) to Tathra in New South Wales (36º 48’ S). The material examined is largely from the collections of the Australian Museum, Sydney, with additional material from Museum Victoria, Melbourne and the Queensland Museum, Brisbane. Australian type material, previously identified specimens, and material currently identified only to genus are included in the analysis. A standardized morphological character set and morphometric methods are used to accurately estab- lish the number and distribution of morphotypes and important characters for identification. Preliminary results indicate synonymies between some existing species and distribution range extensions. It is also expected that new morphotypes will be found. Results may be of economic and biosecurity management significance as the occurrence and distribution of some polydorid pest species over the area is clarified. This study contributes toward a better knowledge of polychaete biodiversity in Australia and is a precursor to a more extensive revision of the Australian poly- dorids.

Presenter (*) 200 Poster Abstracts

Vigtorniella sp. nov., a bacteriovore chrysopetalid from whale-fall and fish farms in the north- east Atlantic

Wiklund, Helena1*, Adrian G. Glover2, Per J. Johannessen1, Craig R. Smith3 & Thomas G. Dahlgren1

1 Göteborg University, Göteborg, Sweden 2 The Natural History Museum, London, UK 3 University of Hawai’i at Manoa, Honolulu, Hawai’i

The chrysopetalid genus Vigtorniella (the carpet-worm) has been recorded from a range of reducing environments in both deep-sea and shallow-water locations. The first described Vigtorniella species was Vigtorniella zaikai Kisseleva, 1992, from sediment in an oxic-anoxic zone in the Black Sea, and a few years later Vigtorniella flokati Dahlgren et al., 2004 was found on deep-sea whale falls in the Pacific Ocean. We have discovered a new species of Vigtorniella living on an experimentally implanted Minke whale carcass at 125 m depth in the North Sea. Aquaria observations of live speci- mens of Vigtorniella sp. nov. indicate that it is grazing on bacterial mats covering the whale bones. The new shallow-water Vigtorniella species seems to be morphologically indistinguishable from V. flokati. However, molecular studies of cytochrome c oxidase subunit I (COI) reveal a difference between V. flokati and Vigtorniella sp. nov. of ~11.5 %, based on Kimura-2-parameter genetic dis- tances. A calibration of the molecular clock for COI in deep-sea annelids (Chevaldonné et al. 2002) suggests a divergence time of about 30 million years for the two species. While V. flokati was thought to be a whale-fall specialist, the new Vigtorniella species has also been found in benthic samples from fish farms in Norway, at depths of 100–150 m. Based on the distribution of haplo- types using COI, we could not detect any restriction in gene flow between the two populations in the different habitats in Sweden and Norway.

Presenter (*) 201 Poster Abstracts

The simplicity of males: CLSM studies of the muscle and nervous system of Osedax dwarf males

Worsaae, Katrine1* & Greg W. Rouse2

1 University of Copenhagen 2 Scripps Institution of Oceanography, La Jolla, California, USA

The dwarf males of the bone-eating worm Osedax (Siboglinidae, Annelida) have been proposed to develop from larvae settling on females rather than on a bone. The apparent freeze in development and resemblance to larvae or early juveniles with a protostomial ciliary troch has been explained by paedomorphosis. We here present the results of four Pacific species of Osedax dwarf males investi- gated for ciliary patterns, as well as muscle and nervous systems conducted by immunostainings and confocal laser scanning microscopy (CLSM). The four species were all collected from Pacific deep-sea whale carcasses in the Monterey Canyon and prepared for CLSM. Multi-stainings with phalloidin and dapi as well as antisera directed against serotonin (5-HT), FMRF-amid, and acetylat- ed ?-tubulin revealed a simple ventral nervous system and presence of an apical ganglion and a spermioduct opening in front the anterior ciliary ring. The dorsal/ventral orientation, function of cilia, organization of sperm production and release through the spermioduct is discussed.

Presenter (*) 202 Poster Abstracts

Mesonerilla sp. nov. from the Pacific Antarctic Ridge (Nerillidae, Annelida)

Worsaae, Katrine1* & Greg W. Rouse2

1 University of Copenhagen 2 Scripps Institution of Oceanography, La Jolla, California, USA

During a cruise to the Pacific Antarctic Ridge in 2005 with R/V Atlantis (Chief Scientist R. Vrijenhoek, MBARI, California, USA), few specimens of a new species of the genus Mesonerilla were sampled with a slurp gun from DSV Alvin. This is the first record of a nerillid from a hydrothermal vent and the first record of Mesonerilla (Nerillidae, Annelida) from the deep sea. The new species possesses nine segments, a prostomium with two short palps and two long lateral and one short median antenna, long compound chaetae and short cirriform parapodial interramal cirri in all segments, and two relatively short cirriform pygidial cirri. Interestingly, the species resembles the interstitial Mesonerilla roscovita described from shallow waters in Europe by the presence of a short median antenna. However, the new species differs distinctively by the presence of chaetae in segment one, much shorter length of the interramal cirri of segments 2–9, and a larger body size.

Presenter (*) 203 Poster Abstracts

Polychaetous annelids from the northeastern coast of Tunisia

Zaabi, S., P. Gillet*, M. Boumaiza & A. Afli

Université Catholique de l’Ouest, Angers, France

In Tunisia, studies concerning polychaetes are very rare (Fauvel, 1924a, b; Westheide, 1972; Ben Amor, 1984; Zaabi, 2005). Actually, there is no updated inventory since that of Ben Amor (1984). The aim of this study is to contribute to fill this gap. Samples were taken aboard the R/V Hannibal by using a Van Veen grab and a cylindrical core. In total, 14 stations were sampled in 2005 and 2006. They are located on the northeastern coast of Tunisia, from Sidi Daoud to El-Haouaria. The majority of specimens were identified to the specific level. A total of 554 individuals belonging to 35 families and 109 species were identified. Some of these species are announced for the first time in Tunisia such as the pilargid Sigambra tentaculata (Treadwell, 1941) and the paraonid, Aricidea fauveli Hartman, 1957. At the same time, the main biodiversity parameters were established. They show that abundance and species richness are higher in shallow waters dominated by Protodorvillea kefersteini (MacIntosh, 1869) and Malacoceros fuliginosus (Claparède, 1868) than in deep waters where Hyalinoecia fauveli Rioja, 1918, and Euclymene palermitana (Grube, 1840) dominate. In addition, some multidimensional methods were used to characterize spatial structure and temporal variability on the different sites (Shannon diversity index, rank frequency diagrams, etc.). They per- mit additional elements to be used to understand the ecosystem organization.

Presenter (*) 204 Poster Abstracts

Outline of the anterior innervation in Eunicida and its implications to hypotheses of homology

Zanol, Joana

George Washington University, Washington, D.C., USA

Eunicida families are commonly identified by the shape of their differing prostomium and pharyn- geal structures. However, current hypotheses of homology among these structures are inconsistent, making the use of such characters in morphological phylogenetic studies problematic. A better knowledge of the homologies among different features of prostomial structures such as buccal lips, and of pharyngeal structures is of great importance to understand the evolution within the order and its place in the annelid tree. In order to build more consistent hypotheses of homology among these structures, we examined under confocal laser scanning microscope specimens of Eunicidae, Onuphidae, Oenonidae, Dorvilleidae and Lumbrineridae stained with anti ?-tubulin and serotonin antibodies. The general pattern of the brain is similar to that described in previous studies. However, we recognized a fourth ventral commissure of the ventral root (vcvr) ventral to vcvr3 and connecting the nerves innervating the ventral and dorsal buccal lips of Onuphidae. The nerves connected to vcvr4 in Eunicidae and Lumbrineridae innervate the ventral side of the prostomium, supporting the hypothesis of homology between the ventral side of the prostomium in these families and the buccal lips of Onuphidae. A pair of esophageal nerves extends from the posterior end of vcvr3 running dor- sally up to the esophagus through muscles posterior to the prostomium and anterior to the pharyngeal bulb. The structures that bear these muscles vary in length and shape among the different families, but are in the same relative positions and have the same nerves passing through them, similarities that support their homologous status. The two hypotheses of homology proposed here may be of importance in adding supporting synapomorphies for Eunicida families and in the case of Eunicidae furnishing perhaps the only synapomorphies supporting this family grouping.

Presenter (*) 205 Poster Abstracts

Mitochondrial genomes of terebelliform worms

Min Zhong, Torsten H. Struck, & Kenneth M. Halanych

Auburn University, Auburn, Alabama, USA

Mitochondrial genomes can be useful for inferring animal phylogeny. Because the rate of evolution varies among different lineages, mtDNA data can provide resolution at differing taxonomic levels. To further understand the phylogenetic potential of complete mitochondrial genome sequence data in Annelida (segmented worms), we obtained mitochondrial genome data for three terebelliform worms (Eclysippe vanelli, Ampharetidae; Pista cristata, Terebellidae; and Terebellides stroemi, Trichobranchidae) and are currently trying to obtain data from a pectinarid (Pectinaria sp.), an alvinel- lid (Paravinella sp.) and another ampharetid (Auchenoplax crinita). The goal of this work is to eluci- date phylogenetic relationships among the five recognized families within terebelliformia: Alvinellidae, Ampharetidae, Pectinariidae, Terebellidae, and Trichobranchidae. mtDNA gene arrange- ment is identical for Pista cristata and Terebellides stroemi, which are different from Eclysippe vanelli in several protein-coding and tRNA genes. Thus, the evolutionary conserved pattern of mitochondrial gene order across annelids is more limited than previously hypothesized. Both gene orders and DNA data reveal close affiliation between Trichobranchidae and Terebellidae as traditionally hypothesized based on morphology. All of four genomes are AT bias and microsatellite-like repeated sequences were found in the control region of both Terebellides stroemi and Pista cristata, which indicates potentially complex secondary structures. The presence of two methionine tRNAs appears to be unique to Trichobranchidae and Terebellidae. Combined with other annelid mitochondrial genomes reported previously, our data also suggest a preliminary phylogenetic relationship within terebelliform worms. Three terebelliform families (Trichobranchidae, Terebellidae and Ampharetidae) come togeth- er and form a monophyletic group, which is associated with Maldanidae.

Presenter (*) 206 8/13/07

9th IPC Updates

Tuesday, August 14

Poster 12 canceled Poster #37 added: Ecological response of polychaetes to an open ocean aquaculture system at Isla Culebras, Puerto Rico Andres G. Morales and Mónica Alfaro Biology Department, University of Puerto Rico, Mayagüez Campus A spatial and temporal characterization of the benthic macroinfauna was done in response to the installation of two cages for open ocean fish culture placed 28 m deep and located 3.2 km south of Isla Culebra , Puerto Rico. Bimonthly sediment samplings (October 2002 to October 2003) were obtained in the north, south, east, west and at center sites under each cage and in a control site. Nutrient concentration, organic matter content, and sediment tex- ture were determined. Organisms were identified to the lower taxonomic level. Nutrient con- centration was low and constant over time and space, and a significant increase in organic matter content was observed only in October 2003. Polychaetes were the numerically domi- nant assemblage of total invertebrates, with 29 families. Nereidae (17% Glyceridae (13.3), Capitellidae (9.7), Spionidae (9.2%), Magelonidae (7.5%), Syllidae (6.2%) y Lumbrineridae (6.0%). Temporal and spatial patterns of the most numerically dominant polychaete families were characterized by a significant interaction between sampling dates and stations, with a higher abundance during October 2002, the first sampling month. A decrease in abundance in some families was observed through the study year. However no significant changes were observed in the abundance and diversity of polychaete families that have been used as indi- cators of pollution, suggesting that the current speed (20-30 cm/s) at the study place seems to play an important role avoiding pollution for this type of aquaculture or perhaps other polychaete species are more susceptible to lower levels of organic pollution in this Caribbean area.

Reminder: breakfast will not be served on Wednesday morning