A new subfamily from Gorong, Seram, Moluccas, with the description

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Transcript of A new subfamily from Gorong, Seram, Moluccas, with the description

  • Bull. Mus. natn. Hist, nat., Paris, 4 e sr., 2,11980,

    section A, n 2 : 507-515.

    A new subfamily from Gorong, Seram, Moluccas,

    with the description of Renaudcypris new genus

    (Crustacea, Ostracoda)

    by K . G. M C K E N Z I E *

    Rsum. Le genre Renaudcypris nouveau genre est signal pour la premire fois Gorong. Les caractres de ce genre imposent la cration d'une nouvelle sous-famille. L'importance de cette dcouverte est discute.

    Abstract. The genus Renaudcypris n. gen. is described for the first time from Gorong. The characters of this genus indicate a placement into a new subfamily. The significance of this record is discussed.

    Among t he collections made by Th . MONOD dur ing his Rumph ius I I expedit ion to Indonesia, t h e inters t i t ia l faunas were sorted and identified to groups by J . R E N A U D -MORNANT . An oppor tun i ty to examine Ostracodes from these collections arose during a working visit t o R E N A U D - M O R N A N T ' S l abora to ry in November 1978. The most a b u n d a n t Ostracode was very dist inct ive. In spite of some deter iorat ion in the carapace due to weak ac id i ty of t he preserving medium, it soon became obvious t h a t a new generic t axon was indicated, even a new subfamily. Subsequent searches of the l i tera ture have con-firmed this ini t ial j udgemen t . Therefore, the genus Renaudcypris and subfamily Renaud-cyprinae are here described for the first t ime.

    OSTRACODA Latreille, 1806

    Order PODOCOPA Sars, 1866

    Superfamily C Y P R I D A C E A Baird, 1845

    Fami ly PARACYPRIDIDAE Sars, 1923

    Subfamily R E N A U D C Y P R I N A E n. subfam.

    DIAGNOSIS : A subfamily of Paracyprididae characterised by a spinose subquadrate carapace, the valves of which are slightly depressed anterodorsally near the eye region ; and a soft anatomy

    * Riverina C.A.E., Wagga Wagga, 2650, Australia.

  • 508

    which includes antennaJ natatory setae reaching to the ends of the antennal claws ; an elongate maxillule palp ; a stout end claw on the terminal segment of the third thoracic- limb (P III) ; rather short, curved furcal rami each bearing two posterior bristles as well as an anterior bristle and two powerful pectinated terminal claws. In males, the clasping palps of the right and left first thoracic limbs (P I) are similar, i.e. not dimorphic ; the Zenkers Organ has 5 inner chitinrosettes ; and in the hemipenes, the tubes of the testes form near circles which open dorsally.

    DISCUSSION

    M C K E N Z I E ( 1 9 7 9 ) in a recent review of Paracypr id idae defined it as compris ing t he subfamilies Paracypr id inae , Thalassocypridinae and Cyclocypridinae ; and subsequen t ly GHETTI and M C K E N Z I E ( 1 9 7 9 ) upgraded Cyclocypridinae to a separa te family. The

    new subfamily is characterised in par t by long n a t a t o r y setae on the an tennae . Even so, the setae are not as long as in Cyclocyprididae in which they typical ly ex tend far beyond the an tennal claws bu t are similar in length to those of m a n y Thalassocypr id inae ( K E Y -SER, 1 9 7 6 ) . In other characters , the soft a n a t o m y is paracypridid- l ike. Thus , as wi th most other paracypr idids , the maxillule palp in Renaudcypris is elongate and the respi-ra to ry epipod of this l imb has about 2 0 " Strahlen " and 3 downwards-di rected setae ; the P I in males is two-segmented and non-dimorphic ; the P II is elongate with a long terminal claw ; the P I I I has a s t rong terminal claw (similar to Paracypris) ; t he furca has two posterior bristles (versus one in all Cyclocyprididae) and the hemipenes are not beaked (they are in cyclocypridids).

    From thalassocypridines, the new subfamily is readily dist inguished by its spinose, subquadra te carapace and the different end claw of the P I I I ; from paracypr id ines it can be differentiated again by its carapace and by the long an tenna l n a t a t o r y setae (which are short in paracypr idines) .

    Genus RENAUDCYPRIS n. gen.

    ETYMOLOGY : For J. RENAUD-MORNANT and generic suffix-cypris. The gender is feminine.

    TYPE SPECIES : Renaudcypris gorongae n. sp.

    LOCALITY : Gorong Island, beach with fresh water rivulet. Coralline sand and algal frag-ments. 1 / 2 5 / 1 9 7 5 , coll. Th. MONOD.

    DIAGNOSIS : A renaudcypridine genus characterised by its spinose subquadrate carapace and a soft anatomy as noted above.

    DISCUSSION

    Refer to discussion of the subfamily, and also to conclusions.

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    Renaudcypris gorongae n. sp.

    (Fig. 1-23)

    ETYMOLOGY : For Gorong, the collection locality.

    DESCRIPTION

    Carapace of medium size (about 0.55-0.60 m m in males and 0.60-0.65 m m in females) ; s ubquad ra t e ; anter ior more broadly rounded t h a n the posterior ; dorsum relatively s t ra ight t rending obliquely downwards to the rear from its highest pa r t anteromedial ly , slightly depres-sed (concave) in front of this highest p a r t ; venter a lmost s t ra ight , w?akly inflexed medially ; surface considerably affected by the preserving medium but apparen t ly punc ta t e and covered with spiky hairs ; colour in life unknown ; greatest height an teromsdia l and over 55 % of the length. In dorsal view subelliptical, anter ior more narrowly rounded t h a n the pos-terior, greatest b read th medial and less t h a n half the length. Internal ly , lamellae mode-ra te ly broad anter ior ly and narrow posteroventra l ly ; tine of concrescence narrow, except medioventral ly ; anter ior and posterior vestibules well developed ; selvage weak ; radial pore canals numerous , unbranched , shorter anter ior ly and posteriorly t h a n ventral ly ; normal pore canals scat tered, simple, some indicat ing the presence of a narrow r im ; hinge adont to weakly lophodont , the te rminal elements being slightly expanded ; adduc to r muscle scars of cypridacean type , comprising a group of 4 large and 2 much smaller scars, plus 2 elongate mand ibu la r scars and 2 small upper-frontal scars ; dorsal scars not observed.

    Antennules 7-segmented ; length rat ios of the segments 38 : 13 : 11 : 11 : 11 : 7 : 6 ; dorsa l /ventra l chae to t axy of the segments 1/2, 1/0 (?), 0 /1 , 2 /1 , 2 /1 , 5/0 ; plus 2 long ter-minal n a t a t o r y setae and a single shorter distal seta wi th a sensory t ip ; the dorsal setae of the 4 th , 5 th and 6 th segments are long and na t a to ry . Antennae 5-segmented ; length ratios of the 3 endopod segments 4 : 2 : 1 ; vent ra l sensory bristle of the first endopod segment su tured medially ; n a t a t o r y setae 7 in number , one short the other 6 abou t equally long and reaching to the t ips of the te rmina l claws ; second endopod segment wi th 3 dorso-distal claw and the th i rd endopod segment wi th a single te rmina l claw ; exopod comprising a single long bristle plus 1 or 2 very small bristles sited proximodorsal ly on the first endo-pod segment . Mandible coxales wi th 6 tee th , plus small anter ior and posterior bristles, the an ter iormost too th is s t rong and simple, the second and th i rd t ee th are t r icuspate and the remain ing 3 t ee th are simple ; the coxal muscula ture makes it clear t h a t this is a t rans-verse-bit ing s t ruc ture capable of some promotor - remotor m o v e m e n t ; endopod 4-segmented, length rat ios of the segments 10 : 9 : 10 : 6.5 ; dorsa l /ventra l chae to taxy of the endopod segments 0/3, 2 /3 , 4 /3 , plus 3 claw-like te rmina l bristles ; epipod obscured. Maxillules wi th palp elongate, two-segmented ; th i rd lobe wi th 2 smooth tooth-l ike bristles ; epipod with abou t 20 St rahlen plus 3 downward-poin t ing setae. Maxillae (P I) in females with an unsegmented endopod bear ing 3 short t e rmina l setae ; epipod with 5-6 Strahlen ; exopod with a b o u t 12 s t rong food-forwarding bristles ; in males the palps (endopods) are modified into t he typica l 2-segmented cypr idacean clasping organs and are not dimorphic (i.e. r ight and left palps are similar). Walk ing legs (P II) 5-segmented ; the first endopod segment finely h i rsu te ven t ra l ly ; t e rmina l claw long and only slightly curved. Cleaning limbs

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    FIG 7 - 1 1 , 1 4 , 1 6 . Renaudcypris gorongae n. gen., n. sp., female : 7 , mandible coxale ; 8 , mandible endopod'(epipod obscured) ; 9, maxillule palp and lobes; 1 0 , maxilla ( P I ) ; 11, walking leg ( P I I ) , 1 4 , cleaning limb ( P I I I ) ; 16, furca.

    FIG. 1 2 , 1 5 , 1 7 . Renaudcypris gorongae n. gen., n. sp., male : 1 2 , left palp P I ; 13, right palp P I ; 1 5 , hemipenis; 1 7 , Zenkers organ.

  • . 18-23. Renaudcypris gorongae n. gen., n. sp. : 18, internal view LV, male X 112 ; 19, detail, ante-rior RV, female, X 450; 20, external view RV, female, X 112 ; 21, external view carapace, female, X 112 ; 22. detail, surface hairs and normal pore canals, female, X 450 ; 23, detail, muscle scars (slightly skewed), X 450.

  • 513

    (P II I ) reflexed ; 4-segmented wi th the th i rd segment su tured medially into approximate ly equal subsegments and each of these subsegments bear ing a dorsodistal hook-like process ; the te rmina l segment wi th a slender modera te ly long reflexed seta, a s t rong b u t slightly shor ter t e rmina l claw and a short seta. Chitin suppor ts wi th simple distal points ; forked proximal ly ; the anter ior b ranch s t raight , the posterior b ranch s trongly recurved. Furca l rami curved, shor t and thick, length : height ra t io about 6 : 1 measured a t the mid- length ; a r m a t u r e of 2 s t rong claws, the anter ior claw a li t t le longer, plus a shor t anter ior brist le and 2 posterior bristles, t he first of these posterior bristles longer t h a n the second. L a b r u m simple, (?) serra te an terovent ra l ly . Cups of t he nauplius eye fused. Rake-shape