THE WASMAXX )OUR~AL OF BIOLOGY

\ 01.• ,\-l. ·o. 1 SrlliNG, l9i6

The Life Cycle of bodegensis, New Species (Coelenterata, ) from California, and a Comparison with Hydrocoryne miurensis from Japan

JOHX T. REES, CADET I11\~D . and CLAUDIA MILLS,' Bodega Jlariue Laboratory mrd Drparlmeut of Zoology, l."rti-!Jersity of Calijomia, Bnd~ga Bay, Califomia 9~923

JNTRODUCTION The hydrozoan family Hydrocorynidae was erected by \Y. ]. Rees ( 195 7) to include the Japanese hydroid llydrocorync miurensis ( tcchow). The polyp is notable for its large size, up to 6 em long or more in state of expansion. The description of the polyp by techo w ( 1907, 1909) was followed by observations on the immature medusa. (Uchi da, 1932) and th e life cycle, including a description of the mature medusa (Uchida and Nagao, 1967). The medusa of T/ . miurc11sis is typically corynicl, and has four equally developed tentacles throughout its developmenl. This paper describes the life cycle of a new species of Hydrocorync, II. bodc!{cnsis new species, from Cali fornia, and compares it with that of li'ydrocoryne miu­ rcnsis from Japan.

)fETHODS A);D ) J ATERL\LS Colonies of Ilydrocor;me bodexcnsis were collected from a popu­ lation found on the jetty marking the entrance to Bodega Harbor. All colonies were collected subtidally from 5-10 feet in depth with the aid of SCUBA from the vertical faces of the large rocks which were used to construct U1e jetty. Colonies were removed from the

' l'rcscnl uddn•;s: 7044 50lh Avenue N.E., Sculllc, \V n< hi n~ llln 9811 5

l JOSJ IIJ"DROCORY.\ E- REES, H:\XD, MILLS 109 rocks with a knife, placed in plastic co ll ec tin ~ containers, and re· turned to the laboratory. The colonies, with their basal mat intact, were placed in finger­ bowls in a water table provided with running sea water. ~ledusae were released over a period of several days and were placed in 600 ml beakers provided with gentle aeration. The beakers were placed in the water table and maintained a t a temperature of I 0- 14 • , that of the ocean locally. T he water in the beakers was changed every 2 days, at which time the medusae were fed enough brine shrimp so that a few shrimp remained in the water. The polyps were maintained on the water table, either in fingerbowls or in beakers. attached to glass microscope slides by pieces of string. The polyps did not attach themselves to the slides.

DESCRIPTION IJydrocoryne bodegensis Rees, Hand & :\.fills, new species. ( FJGUJU:S l -3) llydrocory1u sp ., Rt..t..S and HAxo (1975 : i J, 74 , 81). PoLYP. olony unbranched. arising from a chitinous, basal mat. ~r ature polyps large, from 0.5 to 6.0 em or more high, depending on the state of contraction. Tentacles capitate, 30-50 in number, a nanged in a. terminal cluster. Medusa buds mounted on a branched pedicel located in the proximal half of the hydranth. Cni dom sim­ ilar to H ydrocorync miurensis, except for a micro basic eurytele with a soli d inclusion.

)JEDUSA. I\lalure medusa small, from 1.5 to 2.3 mm in bell height. Four tentacles present "itb hemispherical nematocyst bat­ teries along their l e n~ th s and temlinating in a large, spherical clus­ ter of nematocysts. Ocelli red. Orange to red-brown pigment present in the tentacle bulbs and base of the manubrium. )[anubrial pi~menl variable in form and occasionally absent in adult medusae, although in newly released medusae always in a strip at the base of the manubrium. Bell nol spherical. wider at the apex than at the base. \\'ell-developed peduncle present. Four nematocyst clusters present on the lips of the manubrium. Gonads four in number interradially situa.tecl . Eggs la rge ancl few in numhcr. --

110 THE \\"ASMA~~ JOUR1\AL OF BIOLOGY, YoL. 34, Xo. I, 19i6

FtGURL I. /lydrocoryne bodegmsis, new species. (A) Polyp stage, the polyps arise from a basal mal. drawn from the photo~raph of a Ji,ing . (B) Me­ dusa sta.:c, nc'' ly released medusa, dra\\n from a preserved specimen.

RESULTS The polyp, as nearly as can be determined, is very similar in morphology to the polyp of llydrorory nc miurensis, as descri bed by Uchida and Nagao (1967). As shown in fi gure lA, the colony 1/YDROCORl'X£- REES, HA:\D. MILLS 111 is unbranched, and arises from a chitinous, basal mat. The fully developed polyps are lar!!;e. from 0.5 to 6.0 em or more in len~ tb , dependin~ on the state of contraction. The contracted polyp body is extensively wrinkled. There are from 30-50 capitate tentacles, de­ pending on the age of the polyp. :.\Iedusa buds a re borne on branched pedicels which arise about Y4 of the way from the base of the polyp. The California polyps do possess a second type of macrobasic eury­ tele not reported from the J apanese species, which wi ll be dis­ cussed later. The newly released medusa is relatively Jargt·, from l J to 1.5 mm in bell height. The bell is subspherical, and densely packed with nematocyst clusters, which contain 4-16 nematocysts each (fig. I B). The manubrium is conical in shape and hangs about · ~ way into tl1e bell cavity in full extension. Four nematocyst clu ters are pres­ ent around the mouth. .:\o peduncle is present Gonadal anJaaen appears as an opaque area surrounding the manubrium. There is a distinct area of red-brown pigment which completely surrounds the upper third of the manubrium. The pigment is compo ed of dis­ crete granule which are in dense concentration at the base of the manubrium, and in lesser concentrations in the tentacle bulbs and the tentacles. The bell is tinged with green. In full extension the four tentacles stretch three times the length of t.he bell height. Spherical nematocyst batteries stud the tentacles. T he tentacles ter­ mi nate in a large, spherical cluster of nematocysts. The mnjor developmental changes of the medusa lake place during the first week ( fi ~. 2A) . T he size of the medusa has increased to between 1.5 to 2. 1 mm in bell height. The exumbrellar nema­ tocyst clusters become spaced further apart on the exumbrellar surface, undoubtedly due to the growth of the bell. A peduncle has formed, and tlle manubrium may extend !}~ of the way to tlle velar openin~ . The ~onad matures and appears interradially as four discrete units. From above the mature !!;Onad is cruciform in shape (f i ~ . 28 ). Thickening of the jelly Lakes t•lace, so that at its 1 thickest at the bell apex the jelly accounts for , of the bell hei~hl. There is a second local thickening of the jelly toward the base of the brll. The formerly heavily pigmented an•a of the manubrium is much less pigmented and has divided into fCtu r indistinct patches. All of the morphological changes between 1-week-old and 3-week­ olcl merlusac involve alteration of existi ng structu res and no new 112 TilE \\"AS~L-\:\:\ JOURK.\L OF BIOLOGY, \'oL ..l-1, :\o. 1, 19i6

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Fu:uKE 2 1/,vdrocoryne bodegensis, nc\\ species. (A) One-week-old medusa. drawn rrom a prcsen·ed specimen, pa~tmrntcd areas not ~ hown . ( B) Gonad of a one-week-old male medusa, top 'ic'' CC) Tlm:c-weck-old medusa. drawn lrom a pr\.'~n·cd specimen. morphologies are formed (fig. 2C). The medusae increase slightly in size, growing to 2.2 to 2.3 mm in bell height. There are rela­ tively fewer nematocysts per cluster than in 1-wcek-old specimens. The gonad is slightly enl arged, and extensions of the gonad on ··--

HYDROCORJ' .YE- REES, H:\~0, M ILLS 113

the radial canal associated with the peduncle have increased sli~ht l y in length. l11e peduncle reaches more than L: of the way into the bell cadty, and the manubrium reaches almo'>t to the bell mar~in. Pigment as...c;ociated with the manubrium in I to .)-week-old medusae was found to be variable in fo rm and color. In :.even mature specimens of an un known age examined from the plankton collected 28 October 197.3, the pigmented areas of the manubrium we re orange and varied in form from single blotches to a continuous band. Tn three-week-old specimens rea red in the laboratory, no pigment was visible. E ight separate pigment patches, character­ istic of II. miurcnsis were not seen. La horc1t ory-reared medusae Ji ved to a maximum age of 32 days.

TYPE LOCALITY. Bodega Bay Sonoma Cot.nty, California (38• 18' X lat., 123• 2' \\' long.). Polyps collected on rocks of the Bodega Harbor jetty at about 3 m deep.

TYPE MATF.R!,\L. The following have been depo ited at the . ra­ tional ~ l useum of l\"atural History (Smithsonian 1nstitution) : Holo­ type: 3-week-old mature medusa reared in the laboratory, p1esen ·ed 4 'ovember 1973, liS:\"M 54251. P aratypes: four lots of medusae: ( I ) newly released, preserved 13 September 1973, C ~ ~ I 54253; (2) 1-wcck-old, reared in the laboratory, preserved 23 October 1973, USNlVI 54255; (3) 2-week-old, reared in the labora tory, p reserved 4 November 1973, USNM 54256 ; (4) two lots from the plankton collected 19 November 1971 and 8 December 197 1, USN:\1 54254 ; two lols of polyps: ( J ) 2 polyps, (2) 3 polyps: both collected with SC BA on 12 September 1973, USN::\1 54252, 54257.

ETntOLOCV. The specific name is from Blldega Bay, the type locality.

CNtOOM OF THR POLYP AND MEDUS,\. Two polyps and four medusae were examined live for nematocysts. The cnidom of II. miurensis as reported by Cchida and Kagao ( 1967: 207- 209) is compared with //. bodc.tr,fnsis (table 1 ). T he nemalocyst types arc the same except for a second type of microbasic eurytele '' i th a spherical inclusion fou nd in the polyp of the Bodet-(a speci mens (fig. 3). This type of eurylele was not reported from the Japanese ~pecics. T he inclusion was always found at the broader end of the un discharged capsule of the eury telc and measured about 4 '"min diameter. When TABLE I. Compariso11 of tire Cnidoms of H. miurensis a1rd H. bodegensis ( measuremmts rxpresud i11 p.m).

lfirrii/IUJir rur yt r lrs

Stru()trlt!J Type It (wl1h I'Oiid. spherical Size I Size 11 Type I lncl u.

Polyp (tentacles only) ll. miurensis 19-24 X 13.5-18.0 7- U X 4.5-9.5 15-20 X 7.0-10.5 absent H. bodegnrsis 21-26 X 15-18 6.5-14.5 X S-9 17- 19 X 8.5-9.0 16-10 X 7-8

on t>umbrtll~ on lip< of StUtulffa manubrium B11Jilriclu111J IJri( lruNr Size I !;,,... II ""'/()lfcflla mwlu:os Stc11u1da

:\ledusa (newly released) H. miurcnsis 12.0-13.5 X 8-11 8.0-10.5 X 6-8 7-8 X 4.0-4.5 10-13 X 7-10 8-10 X 4.5-6.0 14.5-15.0 X 9 fl. bodegcnsis 15.5-18.5 X 12- 13 10.0-12.5 X 7-8 8-9 X 4.5- 5.0 9.5-IZ.S X 8.0-9.5 10-1 1 X 5-6 no data a\·nilablc liS TilE \\'ASJ\1.-\.."\:;- ]OUR:'\AL OF BIOLOGY, \'oL. 34, ~o . 1, 1976 was in part supported by grants from the . F, GB-22851 and GB-35592.

LITE1MTURE CITED

IJIGI LIIW1 II. IJ . 1909. The Medusae. Reports on the scientific results or the expedition oi the .S. F'sh Commission steamer " :\lhatross." Memoirs o i t he M usl• um of Comparati\·e Zoo l o~:y at Harvard College, number 3 7: 24.l pp.

D ,\\'Jl)SON' L. 1966. Dcscri(>t ion of a possible new species of the hydroid l/ydrowryne. Reports Zoology S-212-2 14 Bodega Maline Laborato1y 60, (6): 9 pp.

R~:;ES, J T and C. fu:m 1975. Class Hydrozoa. pp. 65-85. I n Li~:lll's Manual. Intertidal lm·erle­ bwcs of the Central California Coast. Third Edition. R. I. Smith and ] . T . Carlton, editors. ni\'crsity of California Press, Berkeley. Rrr.s, \\" ] . 1957. E\ olutionary trends in the cla~ification of capitate hydroids and me­ dusae. Bulletin of the Britbh ~fu scum (:'\Mural History), Zoology series 4, (9) :451-534.

Sncaow, E. 1907. :'\cui! japanische :\thecala und Plumularidac aus der Sammlung Dr. Dor!ein. Zoologischcr Anzci~:er, 31 (7) : 191- 100. 1909. Hydroidpolypcn dcr japanischcn OstkUste: Athccala Ul, d P lumularidae. Abhandlungcn der Mathematic-Physic Klassc dcr K. Bayer. Akad­ emic dcr \Vissenscbaflen . Supplement- ! : 111 pp.

UCWO.I, T . 1932. The mtdusa of H ydrocorync mittrl'ltJis Stcchow. with a note on the sys­ tematic position of the l!'enus Cytads. Proceed in~ts or the Imperial Academy of Japan 8 (4l:ll5-l38.

Ucrnrl.\, T . and Z. :'\.IGAO 1967. Th ~: liic-history of a Jap;mc.c hydroid. 1/ydroforym! miure11sis Stechow. J ournal of the Faculty of Science, Hokkaido University, Series 6, Zoolol!Y 16 (l): 197- 2 11. HYDROCORI'.\'E-REES, H .-\l'"D, ::\1ILLS 115

A

IO ~m

FJCUJH: .1. Srcond type of microbas;c curylcle from the polyp of H ydro­ rorym· lllldt•grllsis, new species. (:\) Uncfucharged ncmntocyst, showing spher­ ical inclusion (B) .o\ nemalocysl which has been pressed undt'r a CO\'erslip. break:li!C ol thc:> spherical inciusion indicates a solid naturl' plact•d under a cover slip and subjected to pressure, the inclu ion broke in a manner which indicated a solid nature. Its function is unkno'' n. There are notable differences in the size ranges of the nematocysts of the two species, such as in the stenoteles found on the tentacles of the medusa. The cnidom of a 2-week-old medusa was found to be the same as that of the newly released medusa, except the density of those nematocysts associated with cxumbrella, basitricholl s haplonemes and a tri chous is01·hi :tas, is relutively less. There we re a few stenoteles and macrobasic curytcles of type TT 11 6 THE \\':\Sl\1:\X:'\ ]OUR:'\:\L OF BIOLOGY, \ uL . •H. :'\o. 1, 1976

TABLE Z. M OJOr morphological dijjrrrnus btl

Tentacles of polyp with aiJscnl J>rcscnl microiJa~ i c cu rytelc containing a spherical, solid inclusion

Peduncle of absent broad, conicnl, and mature medusa well-developed

Shape of bell spherical not spherical of mature medusa

Pi~:mcnt at IJasc of divided into 8 \':triable; in manuiJrium of mature patches laboratory-reared medu!>.'\ either in four indistinct patches, or absent on the exumbrella of the newly released mt>clusa, but lhese were relatively rare.

CoMPARISON OF JI. miurensis WlTH l/. bodcgcnsis. Table 2 gives a summary of the morphological differences between the 2 species. The polyps are separable by the presence in the Bodega population of a second type of microbasic eurytele with a peculiar sphedcal, solid in clusion. Sexually mature medusae of the two species, while similar in size, are distinct. The peduncle in the California species is well-developed, while absent in those from japan. The shape of the bell and amount and distribution of the manubrial pigment also differ. ]n other morphological respects the animals are similar.

DrscusstoN The polyp of H ydrocorync bodcKcnsis was first reported from the Bodega area by Lloyd Davidson ( 1966) who found colonies on a submer~cd log in about 3 m of water about a mile from the mouth of Tomales Bay. In the fi eld populations of II. bodcgcnsis studied, the polyps were found on vertical rock faces exposed to moderately strong water movement. The polyps were generally in a state of expansion , but contracted readily when disturbed . Gc•nerall y small , IlYDROCORYJYE-REES, HAND, MILLS 11 7 isolated colonies composed of two to six polyps were found, but occasionally larger patches of up to 20 or so polyps were encoun­ tered. The polyps moved freely in the current, the large hydranths swi nging like maces through the water and along the substrate. Food has been seen infrequently within tl1e polyp, but laboratory observations revealed that the polyps would eat large ( 2- 4 mm ) gammarid amphipods. Brine shrimp nauplii were not eaten. A few polyps brought directly from the field were found with ingested gammarid amphipods. The polyp is probably principally a bottom feeder on macrobenthonic crustaceans, and the small colony size insures that all polyps are able to have contact with the substrate. The medusa was found to be phototactic and readily swam to­ wards a light sou rce. The pulsations of the medusa are strong, and send the animal several millimeters through the water alternately to the left and right. Plankton tows have revealed the presence of the medusa from July through D ecember in Bodega Bay and Bodega Harbor. The family Hydrocorynidae at present contains two species of the genus H ydrocory ne. The family is exclusively North Paci fic in distribution. In J apan the polyp of H. miurensis has been re­ ported from Hokkaido and North H onshu. The medusa has been reported from the plankton in the area of the Akkeshi Marine Bio­ logical Station on Hokka.ido. The polyp of H. bodegensis is common on the Bodega Harbor jetty, and polyps which are probably of this species have been found on rocks in depths of up to 40 feet in Bodega Bay and in the Fort Ross area about 20 miles north of the Bodega Tviarine Laboratory. Cadet Hand has seen polyps of a H ydrocoryne type on kelp near Monterey in central Cali­ fo rnia, and intertidally on rocks in southern Cali fornia near San Diego. Bigelow ( 1909) described a medusa, Sarsia resplendcns from Acapulco Harbor, Mexico, which Uchida and Nagao ( 1967 ) be­ lieve may be synonymous with II. mi.urensis. Further collections may reveal range extensions and possible new species of H ydrocoryne on the American vVest Coast or both.

ACKNOWLEDGMENTS Tim Hollibaugh collected some of the animals used in thi s study. Amy Breyer assisted in the culturing of the medusae. This work