UNIVERSITY OF AMSTERDAM. Poland. Lódz, Claude de Broyer. Abstract. Bousfield (1965), however, in his rearrangement. of haustoriids, noticed problems

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1 some Bruxelles, Beaufortia INSTITUTE OF TAXONOMIC ZOOLOGY (ZOOLOGICAL MUSEUM) UNIVERSITY OF AMSTERDAM Vol. 41, no. 18 October 22, 1990 Morphology and systematic position of the Antarctic and sub-antarctic synopiid Cardenio paurodactylus Stebbg, 1888 (Crustacea, Amphipoda) Krzysztof Jażdżewski Department of Invertebrate Zoology and Hydrobiology, University of Lódz, ul. S. Banacha, 12/16, Lódz, Poland & Claude de Broyer Institut royal des Sciences naturelles de Belgique, Rue Vautier, 29, Belgium Abstract Hitherto overlooked morphological characters of Cardenio paurodactylus, a common burrowg subantarctic and west antarctic amphipod, cle the authors to keep this species the family Synopiidae. INTRODUCTION Bullock 1976, Bellan-Santi & Ledoyer 1986). Cardenio paurodactylus was described by Stebbg (1888) on the basis of 4 specimens collected by Bousfield (1965), however, his rearrangement of haustoriids, noticed problems the "Challenger" expedition at Kerguelen defg affities of C. paurodactylus with other Islands. The holotype was a rather small and haustoriid genera. J. L. Barnard & Drummond immature female some 5 mm length. The (1982) briefly mentioned for the first time that genus Cardenio was origally allocated to the family Pontoporeiidae. Delia Valle (1893) Cardenio should be removed to Synopiidae, but fally J. L. Barnard & Karaman (1987) erected repeated part erroneously of for Cardenio the new family Cardenioidae. Stebbg' s drawgs and formation and K. H. Barnard (1932) found and described placed C. paurodactylus his "Gammaridi" the male of C. paurodactylus at South Georgia, between phoxocephalids and haustoriids. Later, Stebbg (1906) formally placed the species Haustoriidae and, until quite like all the subsequent authors he did not pay any special attention to the strikg sexual dimorphism of the gnathopod 1. recently, was followed by most authors However, abundant new material allowed (Schellenberg 1926, K. H. Barnard 1932, Stephensen 1947, Thurston 1974, Lowry & the present authors to describe overlooked morphological characters, to correct some previous 129

2 Fig. 1. Cardenio paurodactylus Stebbg. a: head,, 12 mm. b: head,, 7 mm. c: antenna 1,, 9 mm. d: proximal part of antenna 2 flagellum,, 9 mm. e: idem,, 13 mm. f: coxa 2,, 9 mm. g-k: gnathopod 1. g: distal articles,, 12 mm; h: imm., 5.5; i:, 7 mm; k:, 9 mm (p =propodus). Scale: 100 µm. 130

3 misterpretations or mistakes and to more cor- spiform calceolus as suggested by K. H. rectly defe the systematic position of C. Barnard (1932). (Fig. 1 d, e). paurodactylus. 4. Setae on the article 3 of the mandibular are serted not palp only apically as mentioned by J. L. Barnard & Karaman (1987). The rich MATERIAL Several hundred specimens from some 15 samples, 1977 and 1988 P. (leg. collected between Presler, J. Siciñski, K. Jazdzewski, J. Zychliriski) the shallow sublittoral (15-40 m) of Admiralty Bay, Kg George Island, South Shetlands, West Antarctica. Length of females attas 15 that of males 9 mm, mm. setosity of this article, extendg along at least the half of its ventral marg, was already shown by Stebbg (1888). 5. The maxilliped palp is not 3-articulate (J. L. Barnard & Karaman 1987) but 4-articulate. The is and hidden dactyl mute, vestigial among dense apical setae of the third article. This feature was also noticed by Bellan-Santi & Ledoyer (1986). 6. Coxa 1 is really strongly reduced, nearly RESULTS AND DISCUSSION The origal drawgs of Stebbg (1888) are armed with vestigial, one short seta (Fig. 1 h), but coxae 2-4 are not "poorly" (J. L. Barnard & Karaman 1987) but rather richly setose (Fig. reliable and nearly exhaustive. We will only i 0- present here some aspects of the morphology of 7. Gnathopods females have a structure very similar to that of Synopia, the type genus of C. paurodactylus so far overlooked or misterpreted by former authors. the family. The similarity consists the maly 1. The head (Fig. 1 a, b) is weakly but clearly very short ischium and merus both galeate, contradiction to diagnoses of Cardenio and Cardenioidae by J. L. Barnard & Karaman (1987). In addition, the head of gnathopods, the large, broad, almondshaped carpus gnathopod 1 and long and slender carpus and propodus gnathopod 2, Cardenio is massive and as long as the 2 first with long bristles borderg these articles (see peraeon segments, a condition that is typical of Synopiidae. The rostrum is short and blunt Stebbg 1888, Ledoyer 1979, Andres 1984, J. L. Barnard & Thomas 1989, for species of (very comparable, for stance, to the rostrum Synopia). of Pseudotiron coas J. L. Barnard, 1967) and However, gnathopod 1 C. paurodactylus is strongly sexually dimorphic. The female somewhat stronger males than females. dactyl of gnathopod 1 is vestigial (Fig. 1 g), as 2. The accessory flagellum (Fig. lc) is com- observed already by Stebbg (1888), but is paratively long and consistg of several considered absent by Bellan-Santi & Ledoyer articles, from 2 young specimens up to 5 (1986). On the other hand, the male dactyl is adults. The formation given by Stebbg who (1888), figured and mentioned two articles, was transformed by Delia Valle (1893) to accessorio "ilagelle rudimentale, 1- large and elongate. K. H. Barnard (1932) clearly figured this but misterpreted the of other articles. appendage arrangement The "palm" is not formed by the propodus, but by articolato" and then wrongly repeated by J. L. the carpus, whereas the propodus is much Barnard & Karaman (1987) the diagnosis of Cardenioidae. 3. Antenna 2 is sexually dimorphic, much longer males (5 times longer than head) than females Flagellum has up to (3 times longer than head). 12 articles adults. In males, each article, except some apical ones, is armed with a special hooked spe, not a reduced and forms a short base for the dactyl. Young males of about 5 mm show the length termediate shape of gnathopod 1, clearly dicatg the way which the juvenile (feme) gnathopod 1 is masculized successive moults (Figs, lh, i, k). Distct sexual dimorphism C. paurodactylus is noteworthy view of the opion of J. 131

4 Tironidae), L. Barnard (1972) and Lcoln (1979) on the palp extremely stout Synopia similarity of sexes the whole family Synopiidae. More recent formation by Telson of elongate, exceedg peduncle uropod 3 even when peduncle elongate, Karaman (1986) and J. L. Barnard & Thomas mandibular palp not extremely stout 2 (1989) do show that sexual dimorphism is quite 2. Gnathopod 2 with dactyl; eyes, if present, clear at least such genera like Garosyrrhoe and not very large, eye length not more than 1.5 Syrrhoites. On the other hand, as many synopiid species have been described from sgle holotype specimens or even from type specimen of times the diameter of the antenna 1 base Gnathopod 2 lackg dactyl; eyes very large, 3 unknown it is sex, quite premature to consider eye length more than twice the diameter of all Synopiidae as weakly sexually dimorphic. antenna 1 base Cardenio 3. From couplet 3 one can proceed with the J. 8. Further synopiid features of C. paurodactylus consist long, massive pleon, denticulate L. Barnard's key, takg to account that pleonites 1-3, lanceolate rami of uropod 3 and our couplet 3 is Barnard's couplet 2. long telson strongly exceedg length the uropod 3 peduncle. In conclusion of this brief analysis, it appears REFERENCES to us that, as the head can be regarded as galeate, the only ma diagnostic character distguishg Cardenioidae from Synopiidae remas the strongly reduced coxa 1. But, on one hand, a trend toward the reduction of the coxa 1 exists Latacunga or and Synopia the character state found Cardenio can be regarded as the extreme On the other step. hand, this character alone has no sufficient taxonomic weight, to allow the establishment of a new family. Sce L. Barnard's J. (1972) revision of Synopiidae, where 69 species 14 genera were mentioned, 9 new species were added to this list, all belongg to hitherto known genera ANDRES, H. G., Zwei neue Synopiiden (Crustacea: Amphipoda: Gammaridea) aus dem warmen zentralen Nord-atlantik. Mitt. hamb. Zool. Mus. Inst., 81: BARNARD, J. L., Bathyal and Abyssal Gammaridean Amphipoda of Cedros Trench, Baja California. Bull. U.S. Nat. Mus., 260: BARNARD, J. L., A Review of the Family Synopiidae ( = Maly Distributed the Deep Sea (Crustacea: Amphipoda). Smith. Contrib. Zool., 124: BARNARD, J. L. & M. M. DRUMMOND, Gammaridean Amphipoda of Australia, Part V: Superfamily Haustorioidea. Smith. Contrib. Zool., 360: BARNARD, J. L. & G. S. KARAMAN, Revisions classification of gammaridean Amphipoda (Crustacea), Part 3. Proc. biol. Soc. Wash., 100(4): (Ledoyer 1977, 1979, Just 1981, Goeke 1982, BARNARD, J. L. & J. D. THOMAS, Four species of Andres 1984, Bellan-Santi 1985, Karaman 1986), whereas one species (Garosyrrhoe disjuncta) was L. Barnard & Thomas synonymized by J. (1989). The only new genus, Metatiron, created by Rabdranath (1972) was rejected by Just (1981) and Jazdzewski (1990) as not sufficiently substantiated. Therefore, the present list of Synopiidae cludg C. would paurodactylus encompass 78 species 15 genera. Synopiidae from the Caribbean region (Crustacea: Amphipoda). Proc. biol. Soc. Wash., 102(2): BARNARD, K. H., Amphipoda. Discovery Rep., 5: BELLAN-SANTINI, D., Amphipodes profonds de Méditérranée (campagnes Biomede I, Polymede I et II). Boll. Mus. civ. St. nat. Verona, 10: BELLAN-SANTINI, D. & M. LEDOYER, Gammariens (Crustacea, Amphipoda) des îles Marion et Prce Edward. Boll. Mus. civ. St. nat. Verona, 13: The genus Cardenio fits J. (1972) key the followg way: L. Barnard's BOUSFIELD, E. L., Haustoriidae of New England (Crustacea: Amphipoda). Proc. U.S. Nat. Mus., KEY TO THE GENERA OF SYNOPIIDAE 117: DELLA VALLE, A., Gammari del Golfo di Napoli 1. Both telson and peduncle of uropod 3 very Fauna Flora Golf. Neapol, 20: short and subequal length, mandibular GOEKE, G. D., Tiron triocellatus, a new species of 132

5 , amphipod (Gammaridea: Synopiidae) from the mare gammaridean Amphipoda of the Southern Western Atlantic and Gulf of Mexico. J. Crust. Ocean. Bull. roy. Soc. N.Z., 16: Biol., 2: JAZDZEWSKI, K., (1990). A redescription of Tiron antarcticus K. H. Barnard, 1932 (Amphipoda, Synopiidae) with an updated key to the species of Tiron Liljeborg, Proc. biol. Soc. Wash., 103 (1): RABINDRANATH, P., Three Species of Gammaridean Amphipoda (Crustacea) from the Trivandrum Coast, India. Zool. Anz., 188: SCHELLENBERO, A., Amphipoda 3: Die Gammariden der deutschen Tiefsee- Expedition. Wiss. JUST, J., Tiron bellairsi n. sp. (Amphipoda, Synopiidae) from Coral Sand Barbados with Notes Ergebn. Deutschen Tiefsee-Expedition , 23: "Valdivia" on Behaviour. Zool. Ser., 10: KARAMAN, G. S., Several poorly known or new STEBBING, T. R. R., Report on the Amphipoda collected by H. M. S. Challenger durg the years species of families Synopiidae and Phoxocephalidae 76. Report on the Scientific Results of the Explorg from the Mediterranean Sea (Contribution to the knowledge of the Amphipoda 158). Glas, odjel. prir. Voyage of H. M. S p. Challenger, , 29: nauka., 5: LEDOYER, M., Contribution à l'étude de l'écologie de la faune vagile profonde de la Méditérannéenord occidentale. 1. Les gammariens (Crustacea, Amphipoda). Boll. Mus. civ. St. nat. Verona, 4:, Amphipoda. 1. Gammaridea. Das Tierreich, 21: STEPHENSEN, K., Tanaidacea, Isopoda, Amphipoda and Pycnogonida. Sei. Res. Norw. Antarct. Exp., 20: THURSTON, M. H., Crustacea Amphipoda from Les gammariens de la pente externe du Graham Land and the Scotia Arc, collected by Grand Récif de Tuléar (Madagascar) (Crustacea, operation Tabar and the Falkland Islands Amphipoda). Mem. Mus. civ. St. nat. Verona, 2(2): dependencies Survey. Br. Antarct. Surv. Sei. Rep., 85: LINCOLN, R. J., British mare Amphipoda: Gammaridea: (British Mus. (Nat. Hist.), London). LOWRY, J. K. & S. BULLOCK, Catalogue of the Received: November 22, 1989 Institute of Taxonomic Zoology (Zoologisch Museum), University of Amsterdam, P.O. Box 4766, 1009 AT Amsterdam, the Netherlands 133