Eager, Stephan H.

Read, Geoffrey B.

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New Zealand Natural Sciences (2004) 29: 49-54A new species of Pontocypria (Ostracoda) livingon Chaetopterus sp. (Annelida: Polychaeta) fromHauraki Gulf, New ZealandStephen H. Eagar1,3 and Geoffrey B. Read21Victoria University of Wellington, PO Box 600, Wellington, New Zealand.2National Institute of Water and Atmospheric Research (NIWA), Private Bag:14 901, Wellington.3Corresponding author e-mail: Stephen.Eagar@vuw.ac.nz(Received 4 October 2004, revised and accepted 11 January 2005)AbstractOstracoda (Crustacea) that are parasitic or living in close association with differentanimals have been known for many years, but here we report an occurrence thatappears to be the first from a polychaete worm. Some specimens of the cryptogenicpolychaete Chaetopterus sp., collected off Omaha Beach, Leigh, carried one or twoostracods attached in the head region at the boundary between the ninth andtenth chaetigerous segment. Pontocypria omaha sp. nov. is described and is thefirst record of a species of Pontocypria from New Zealand.Keywords: ostracod - polychaete - commensal - new taxon - Hauraki Gulf.IntroductionCommensal ostracods have beenfound associated with isopods (de Vos1953), fish (Hart 1962), decapods(Hart 1970), sponges (Maddocks1968), echinoids (Maddocks 1979),ophiuroids (Maddocks 1987), and agastropod (Wouters 1991). Perhapssurprisingly, an association withtube-dwelling polychaetes has notbeen encountered until now. Inparticular, Chaetopterus worms oftenhave commensals in their easily-enteredtubes, mainly a variety of polynoidpolychaetes and small decapods(Petersen & Britayev 1997).Commensal ostracods belong to26 genera (Baker & Wong 1968)in the families Entocytheridae,Hemicytheridae, ParadoxostomatidaeXestoleberididae and Pontocyprididae.Ten other species of Pontocypria areknown world-wide and a usefulsummary of the genus is found inWouters (1991). They are foundfrom high latitudes of both thenorthern and southern hemispheresalmost to the equator, and in verydeep and shallow environments, buthave not been previously reportedfor New Zealand waters. They aremostly commensal on Echinodermataand Gastropoda.50 New Zealand Natural Sciences 29 (2004)A sample of numerous parchmentworms, Chaetopterus sp. (Polychaeta:Chaetopteridae), was collected byscallop dredge from a sand gravelbottom, 25 m depth, at Leigh Reef inOmaha Bay, on 21 August 2000, atStation 45 by collector HernandoAcosta (NIWA station Y10331).Worms were kept alive in aquaria atthe Leigh Marine Laboratory untilremoved from their tubes and examinedby the second author GBR on 12December 2000. Four of 15 specimensof the polychaetes had ostracodsassociated with them. No ostracodswere found on Chaetopterus sp. fromthree other samples collected in theOmaha Bay area at the same timeand treated identically to the LeighReef worms. In total seven completespecimens of Pontocypria were found,all attached laterally to the wormsjust anterior to the enlarged aliformparapodial lobes of the tenth chaetiger,one ostracod each side in threeof the four worms (Plate 1, Fig. F).The adults are thought to befemales but the preservation of the softtissue is insufficient to verify thatdetermination.The holotype and two paratypespecimens are deposited in theinvertebrate collections at the Museumof New Zealand, Te Papa Tongarewa,Wellington, with four paratypesdeposited in the NIWA invertebratecollection.DescriptionOstracoda, Latreille, 1806Podocopida Sars, 1866Family Pontocyprididae Müller, 1894Genus Pontocypria Müller, 1894Pontocypria omaha sp. nov.Type LocalityOff Omaha Beach in 25 m of water,Omaha Bay, Hauraki Gulf. Latitude:36° 17·7 S, longitude: 174° 49·86 E.MaterialHolotype: A dissected female (?) withthe valves stored dry and theappendages mounted in glycerine jellyon slides with the edges sealed.Catalogue number NMNZ CR 9999.  Paratypes: two specimens cataloguenumbers NMNZ CR 10,000;10,0001. Stored in ethanol.Derivation of name from the localityOmaha as a noun in apposition.DiagnosisThe living specimen is red, with themaximum height posterior of the mid-point; two setae on the penultimatepodomere of the mandibule; and withsub-equal setae and claws on the furca.DescriptionThe living specimen is red in colourwith a medium-large, fragile carapace,asymmetrically bean-shaped andcovered in fine hairs, which are notobvious. The right valve is larger thanthe left (Table 1). Maximum height isposterior of the mid-point. The surfaceof each valve has many punctae andTable 1.  Valve dimensions (mm) of Holotypeand Paratypes.Length Height WidthHolotypeRight Valve 1.07 0.65Left Valve 1.05 0.60ParatypesCarapace 1.10 0.65 0.60Carapace 0.90 0.65 0.4051S.H. EAGAR & G.B. READ:  A new species of Pontocypria (Ostracoda)there are two depressions on thepostero-dorsal area. The hinge is adont,mainly straight and with a sinuousposterior extremity. The interior of thevalves has uncalcified lamellae withlarge vestibules and a narrow zone ofconcrescence. The normal poreopenings are small and have raised lipssurrounding the apertures. The centralmuscle scars are indistinct but arecomposed of a simple group of five scarsin a horizontal arrangement. Two smallPlate 1.  Pontocypria omaha  Fig. A. Right valve, exterior.  Fig. B. Left valve interior.  Fig. C. Centralmuscle scars, left valve.  Fig. D. Dorsal adductor muscle scars.  Fig. E. Dorsal muscle scar field.Fig. F. Posterior head region of Chaetopterus sp. Two Pontocypria, indicated with arrows, attachedin front of the aliform parapodia and ventral sucker. Scale bars in microns except Fig. F.dorsal adductor scars and a mandibularscar are present. The eye is black.The terminology and abbreviationsfor the podomeres follows that proposedby Maddocks (1979).Antennula: (Figure 1D) Simple andwith five long swimming setae.Podomeres (iv) and (v) may be fused asthere is no distinct boundary. Lengthsof the distal podomeres are:15:18:24:36:69:75 microns.52 New Zealand Natural Sciences 29 (2004)are only two setae on each side ofthe penultimate podomere of themandibule; branchial plate with foursetae.Maxilla: (Figure 1G) With a largevibratory plate with 22 featheredrays. Endite with two, three and fourbristles.1st Thoracic leg (P1): (Figure 1H)Similar to P. coriocellae, which is theFigure 1.  Pontocypria omaha  A. Left valve, dorsal view.  B. Left valve interior.  C. Left valve: detailof hinge line.  D. Antennula.  E. Antenna.  F. Mandible.  G. Maxilla.  H. 1st thoracic leg.  I. Walkingleg (P2).  J. Cleaning leg (P3).  K. Furca.  Bar scales: A  C : 0.1mm; D  K : 100 microns.Antenna: (Figure 1E) With thecharacteristic hooked claw and twoother bifurcating setae. Five natatorysetae from podomere (iv), all of whichare hairy; the terminal podomere (vi)has three bifurcating claws. Lengths ofthe distal podomeres are 39:48:120microns.Mandible: (Figure 1F) With three longclaws on terminal podomere. There53S.H. EAGAR & G.B. READ:  A new species of Pontocypria (Ostracoda)only species illustrated with setae onthe podomeres.Walking leg (P2):  (Figure 1I) This legis five-segmented and the anatomy forthis leg is the same for all species ofPontocypria. Lengths of the podomeresare 18:63:81:141 microns.Cleaning limb (P3): (Figure 1J) Withfour podomeres, the terminal onehas a claw with setae and threestout bristles. Lengths of the podomeresare ?:36:138:228 microns.Furca: (Figure 1K) The hairs and clawsare of similar length. Those of otherspecies have shorter apical hairs, inparticular.Furcal attachment: (Figure 1K) A simpleY- shape.Colour: Strong red to red/brown whenliving; brown to cream in ethanolpreservative.DiscussionThe species most similar to P. omaha isP. helenae Maddocks, 1968, which wascollected attached to asteroids in about300m depth of water in Antarctica. Thecarapace of P. helenae is less arched inlateral view; its maximum height ismid-point and it lacks the depressionsin the dorsal area. P. omaha is smallerthan P. coriocellae Wouters, 1991 andnot sub-rectangular. The mandibule ofP. coriocellae has three setae on thepenultimate podomere but only twoin P. omaha. As the adult specimensare female, there are no diagnosticfeatures on the genitalia.The epifaunal worm hosting P.omaha within its parchment-like tubemay be a Chaetopterus new to science.It does not fit the description of knownspecies (G. Read,  unpublished report),but is as yet unnamed pendingresolution of confused taxonomy in thegenus. It is a cryptogenic species whichincreased dramatically in abundance inand adjacent to the Hauraki Gulf  regionsince first becoming conspicuous therein 1997 (Acosta 2000). Large numbersof Chaetopterus sp. have been examinedfrom populations sampled in this widerregion (Gulf Harbour, WhangareiHarbour, Tauranga Harbour) but furtherostracods have not been found in wormtubes, and also other commensals didnot occur (Read, unpublished data).Thus, the wider distribution of P. omahais as yet unknown. The evidence to datesuggests it is an occasional commensalof the worm. Chaetopterus sp. pumpswater to trap microplankton food in amucous net extending posteriorly fromthe aliform parapodia where the LeighReef P. omaha were attached. Theattachment of all the ostracods only atthis location suggests this was anoptimum position for obtaining foodwithin the worm tube.AcknowledgementsWe are most grateful to HernandoAcosta for providing the samples ofliving Chaetopterus worms and to KerrySwanson of the University of Canterbury,New Zealand for reading themanuscript.ReferencesAcosta, H. (2000). The parchment tubeworm  an alien in the Hauraki Gulf?Dive New Zealand/Pacific 61: 36.Baker, J.H. & Wong, J.W. (1968).Paradoxostoma rostratum Sars(Ostracoda, Podocopida) as acommensal on the Arctic gammaridamphipods Gammaracanthus loricatus54 New Zealand Natural Sciences 29 (2004)(Sabine) and Gammarus wilkitzkiiBirula. Crustaceana 14: 307-311.Hart, Jr., C.W.  (1962). A revision ofthe ostracopds of the familyEntocytheridae. Proceedings of theAcademy of Natural Sciences ofPhiladelphia 114: 579-584.Hart, Jr., C.W.  (1970). A new ostracod(Entocytheridae, Notocytherinae)commensal on New Zealandcrayfish. Proceedings of the BiologicalSociety of Washington 83: 579-584.Maddocks, R.F. (1968). Commensaland free-living species of PontocypriaMüller, 1894 (Ostracoda,Pontocyprididae) from the Indianand Southern Oceans. Crustaceana15: 121-136.Maddocks, R.F. (1979). Two examplesof symbiosis or parasitism inCypridacean Ostracoda. Crustaceana37: 1-12.Maddocks, R.F. (1987). An ostracodecommensal of an ophuroid andother new species of Pontocypria(Podocopida: Cypridacea). Journalof Crustacean Biology 7: 727-737.Petersen, M.E.& Britayev, T.A. (1997).A new genus and species of polynoidscaleworm commensal withChaetopterus appendiculatus Grubefrom the Banda Sea (Annelida:Polychaeta), with a review ofcommensals of Chaetopteridae.Bulletin of Marine Science 60(2):261-276.Vos, A.P.C. de (1953). Three newostracods from Limnoria lignorum(Rathke). Beaufortia 4: 21-31.Wouters, K. (1991). A new species ofthe genus Pontocypria (Crustacea,Ostracoda), commensal of alamellariid gastropod. Bulletin vanhet Koninklijk Belgisch Instituutvoor Natuurwetenschappen, Biologie61: 65-71.

A new species of Pontocypria (Ostracoda) living on Chaetopterus sp. (Annelida: Polychaeta) from Hauraki Gulf, New Zealand

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A new species of Pontocypria (Ostracoda) living on Chaetopterus sp. (Annelida: Polychaeta) from Hauraki Gulf, New Zealand

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