One of the dominant amphipods in algal turf communities at Discovery Bay, Jamaica, is a new species, Gammaropsis arawakia, characterized by long peduncle of uropod 3, small coxa I, 3-articulate accessory flagellum, extremely setose gnathopod 2, one pair of dorsal teeth on urosomite I, pointed ocular lobe, and oblique upper margin of cephalic sinus for antenna 2

Barnard, J. L.

Thomas, James Darwin

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Nova Southeastern UniversityNSUWorksOceanography Faculty Articles Department of Marine and Environmental Sciences1-1-1989Gammaropsis arawakia, a New Species of MarineAmphipoda (Crustacea) from JamaicaJames Darwin ThomasReef Foundation, thomasjd@nova.eduJ. L. BarnardSmithsonian InstitutionFind out more information about Nova Southeastern University and the Oceanographic Center.Follow this and additional works at: http://nsuworks.nova.edu/occ_facarticlesPart of the Marine Biology Commons, and the Oceanography and Atmospheric Sciences andMeteorology CommonsThis Article is brought to you for free and open access by the Department of Marine and Environmental Sciences at NSUWorks. It has been acceptedfor inclusion in Oceanography Faculty Articles by an authorized administrator of NSUWorks. For more information, please contactnsuworks@nova.edu.NSUWorks CitationJames Darwin Thomas and J. L. Barnard. 1989. Gammaropsis arawakia, a New Species of Marine Amphipoda (Crustacea) fromJamaica .Proceedings of the Biological Society of Washington , (1) : 89 -94. http://nsuworks.nova.edu/occ_facarticles/594.PROC. BIOL. soc. WASH. 102(1), 1989, pp. 89-94 GAMMAROPSIS ARA WAKIA, A NEW SPECIES OF MARINE AMPHIPODA (CRUSTACEA) FROM JAMAICA James Darwin Thomas and J. L. Barnard Abstract. -One of the dominant amphipods in algal turf communities at Discovery Bay, Jamaica, is a new species, Gammaropsis arawakia, character-ized by long peduncle ofuropod 3, small coxa I, 3-articulate accessory flagellum, extremely setose gnathopod 2, one pair of dorsal teeth on urosomite I, pointed ocular lobe, and oblique upper margin of cephalic sinus for antenna 2. Gammaropsis arawakia is very abundant in the algal turf that now (1986) covers the heavily disturbed reef at Discovery Bay, Ja-maica. The living coral was damaged by the hurricane of 1980 and any regenerants al-most completely exterminated by algal turf in 1984-1986. This turf developed follow-ing the death of the herbivorous urchins Diadema antillarum (information from Di-rector Dr. Jeremy Woodley). A nearby load-ing dock for bauxite may also be a factor in the disturbance, although we are informed that the coral damage and turf development are common to most of the north coast of Jamaica. Discovery Bay is also character-ized by the presence of large, cold fresh-water seeps. Other amphipod genera pres-ent in this turf mat are Lembos, Elasmopus and Hyale. Isaeidae Gammaropsis arawakia, new species Figs. 1-3 Etymology. -Named for the Arawak, former Indian tribe of the central Carib-bean. Diagnosis. -Ocular lobe projecting mod-erately, bearing sharp anterior cusp, lower antennal sinus with oblique dorsal margin; eyes of medium size, with irregular mass of purple pigment surrounded sparsely by clear ommatidia. Accessory flagellum 3-articu-late, articles 1-2 long, apical article minute. Epistome sharply produced into long an-terior spike. Mandibular palp article 3 cla-vate, with subdistal anterior notch, heavily setose. Inner plate of maxilla I naked, outer plate with 9 spines. Plates of maxilla 2 broad, inner with oblique facial row of 6 setae. Anterior coxae short, coxa 1 less than half as wide as coxa 2, rounded-quadrate an-teroventrally, coxa 3 narrower than coxa 2, coxa 5 as long as coxa 4. Carpus of gnatho-pod 1 longer than propodus, dactyl strongly overreaching oblique palm. Article 2 of gnathopod 2 densely setose mediodistally, carpus short, propodus greatly enlarged, palm oblique, convex, defined by tooth lacking spine, densely setose medially and anteriorly, these setae projecting dorsally and medially. Locking spines of pereopods 3-4 absent, of pereopods 5-7 forming unequal pair. Pereopods 5-7 of similar structure but increasingly longer, article 2 very narrow and smooth posteriorly. Epimera 1-3 similar, each with small pos-teroventral tooth and setule-notch, poste-rior margins weakly convex. Urosomite I with pair of weak dorsal teeth side by side. Uropod I with medium interramal tooth, lacking on uropod 2; each ramus ofuropods 1-2 with elongate apical spine. Peduncle of uropod 3 elongate, rami lanceolate but al-most rod-like, subequal to each other but longer than peduncle, outer ramus with 90 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON • B H Nr Mr dE X2 VOLUME 102, NUMBER I elongate apical spine-setae about as long as peduncle of uropod 2. Telson ordinary. Description of male "a" 2.09 mm. -Left mandibular incisor with four teeth, lacinia mobilis with four teeth, main rakers three. Apex ofpalp on maxilla I with four spines, one apicolateral spine-seta, 3 subdistal fa-cial setae; inner plate short, softly triangu-lar. Inner plate ofmaxilliped with 3 medial setae, 7 apical setae, three stout apical spines, one ventral facial locking spine and one ventral seta; outer plate with four thick ser-rate medial spines, two similar but thinner apical spines and 2 apical setae, ventral sur-face with II scattered setae; dactyl elongate, nail of medium length, with three accessory setules (Figs. 1-3). Apices of rami on uropods 1-2 as in en-larged illustration, with medial elongate spine and short lateral spine, except inner ramus ofuropod 2 with long and short spines reversed. Description of female "b" 2.47 mm.-Oostegites 2 and 5 short, slender, with 2 and 6 setae each, oostegites 3 and 4 twice as long and wide, with 10 setae each; gills 2-3 and 6-7 sac-like, slender, 3 times as long as broad, gills 4 and 5 about 4 times as long as broad, scarcely broader than others. Holotype. - USNM No. 195175, male "a" 2.09 mm. Type loca/ity.-Jamaica station IB, Dis-covery Bay, backreef, I m, 6 Sep 1986, on Acropora palmata rubble mound near chan-nel marker, formaldehyde wash of algal turf, coIl. J. D. Thomas and J. Clark. Material. - Type locality, female "b" 2.47 mm, female "c" 2.14 mm, male "d" 2.03 mm and IS other specimens. Numerous ( 91 specimens from many other similar samples also deposited in Smithsonian crustacean collections. Relationship. - There are IDS species of Gammaropsis so that it was a laborious task to distinguish our species from the score of species that it resembles. To avoid a lengthy discussion we have eliminated those species not fitting significant parts in the following diagnosis: Ocular lobe pointed, short; eyes small; antennae of medium length; coxae 1-5 short and almost evenly extended; carpus of gnathopod I long; carpus of gnathopod 2 short, propodus evenly rectangular, palm shorter than posterior margin of propodus, regular, poorly sculptured, defined, medial surface of hand heavily setose; epimeron 3 with point; urosome with only one pair of dorsal teeth; peduncle and rami of uropod 3 elongate, allnaments of rami very sparse and simple. Gammaropsis (=Eurystheus, Kermys-theus, Podoceropsis, Megamphopus, Se-gamphopus, Pseudeurystheus, see Barnard 1973) contains a diversity of species not yet organized cladistically. Note that Paranae-nia Chilton (1884) is being revived by Bar-nard & Karaman (1989). Gammaropsis ara-wakia resembles Segamphopus and Pseudeurystheus in the elongate carpus of gnathopod I and such species as G. exser-tipes and G. spinosa in the elongate peduncle ofuropod 3. It also resembles several species with densely setose gnathopod 2 such as G. setifera, G. tonichi, and G. tawahi. The nar-row coxa I suggests certain species of M e-gamphopus but most members of that "ge-nus" have other anomalies in gnathopods Fig. I. Gammaropsis araIVakia, unattributed figures ~ holotype male "a" 2.09 mm; d ~ male " d" 2.03 mm. Capital letters denote main parts in the following list; lower case letters to right of capital letters or in body of figure indicate modifications as follows ; lower case letters to left of capital letters indicate specimens described in captions: B, body; D, dactyl of thoracic leg; E, prebuccal lateral; G , gnathopod; H , head; M, mandible; N , mandibular molar; 0 , outer ramus; P, pereopod; R, uropod; S, maxilliped; T, telson ; V, palp; W, pleon; X, maxilla; r, right; s, setae removed; t, left. 92 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON MV G1 \ ~ 8 • 5 • 't : 0 • • • "b 0 0 G1 • • • , .• G2 P3 o 6 Fig. 2. Gammaropsis arawakia, holotype male " a" 2.09 mm. Letter codes see Fig. L " , , , , , G2 , r-, " , , , , , RT VOLUME 102, NUMBER I 93 R3 T P3 OR1 06 4 5 6 w Fig. 3. Gammaropsis arawakia, holotype male " a" 2.09 mm. Letter codes see Fig. 1. or other coxae. We have ignored species of "Podoceropsis" and "Kermystheus" which have severely reduced accessory flagella. Gammaropsis tawahi Barnard (1972), from New Zealand, has an elongate pedun-cle on uropod 3 and densely setose gnatho-pod 2 but the palm bears a tooth near the hinge, the apical armaments on uropods 1-3 are all short, mandibular palp article 3 lacks a notch and the antennae are short-ened and sparsely setose. Our species is close to G. averus Reid (1951) from West Africa, but differs in the broader hand ofgnathopod 2 and less sculp-tured palm. Our species differs: From G. sutherlandi Nelson (1981), North Carolina, in the small even coxae 1-5, strongly subchelate gnatho-pod 2 and simpler spination of uropod 3; From G. hirsuta Reid (1951), West Africa, in the more sculptured palm and long prop-odus of male gnathopod 2 and the longer carpus ofgnathopod I; From G. tonichi Bar-nard (1969), Pacific Mexico, in the presence of only one pair of teeth on the urosome, and the lack of radical transformations oc-curring in male gnathopod 2 and coxa 7; From G. spinosa Shoemaker (1942), Pacific Mexico, in the small coxae 1-5 and medium (versus very short) antennae; From G. chi/-toni and G. haswelli Thomson (1897), New Zealand, in the sharp ocular lobes, small coxae 5-6 and the ordinary, not grotesque, male gnathopod 2; From the pan-tropical G. atlantica Stebbing (1888) in the normal and small eyes and longer carpus of gnatho-pod I; From G. thomsoni Stebbing (1888), New Zealand, in the more simplified ar-maments on the more elongate rami of uro-pod 3; From G. exsertipes Stebbing (1888), Kerguelen, in the ordinary condition of cox-ae 1-5 (versus enlarged), male gnathopod 2 (versus grotesque or elephantine), epimeron 3, regular length of antennae and sharp ocu-lar lobes; From G. anomala Chevreux (1926), warm eastern Atlantic, in the nor-mal gnathopod 2 and pereopod 5 which in the Lusitanian species are res pecti ve ly weakly palmate and elephantine. The following species also have many 94 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON similarities to ours but differ in two or more of the characters in the diagnosis presented just above: G. dilatata and G. pseudoden-ticulata Ledoyer (1982) from Madagascar; G. pacifica and G. setifera Schellenberg (1938) from the middle Pacific Ocean; G. crenulata and G. ulrici Krapp-Schickel & Myers (1979) from the Mediterranean Sea; G. palmata (Stebbing & Robertson, 1891) from Europe; G. ellisi Conlan (1983) from cold-temperate eastern Pacific; and G. 10-bata Chevreux (1920) from Europe. Acknowledgments We thank Janice Clark for her assistance in the field in Jamaica and Kimberly R. Cleary for her assistance in our laboratories at the Smithsonian Institution. Dr. Jeremy Woodley, Director of the Discovery Bay Marine Laboratory, and his staff gave us considerable help in our survey studies. Literature Cited Barnard, J. L. 1969. A biological survey of Bahia de Los Angeles Gulf of California, Mexico, IV. Benthic Amphipoda (Crustacea). - Transac-tions of the San Diego Society of Natural His-tory 15: 175-228. ---. 1972. The marine fauna of New Zealand: Algae-living littoral Gammaridea (Crustacea Amphipoda). - New Zealand Oceanographic Institute Memoir 62: 1-216. ---. 1973. Revision of Corophiidae and related families (Amphipoda). -Smithsonian Contri-butions to Zoology 151: 1-27. ---, & G. S. Karaman. 1989. The families and genera of Gammaridean Amphipoda (except marine Gammaroids).-Smithsonian Contri-butions to Zoology (In press). Chevreux, E. 1920. Sur quelques amphipodes nou-veaux au peu connus proven ant des cotes de Bretagne.-Bulletin de la Societe Zoologique de France 45:75-87. ---. 1926. Amphipodes I.-Gammariens (suite). Voyage de la goelette Melita aux Canaries et au Senegal 1889-1890. - Bulletin de la Societe Zoologique de France 50:365-398. Chilton, C. 1884. Additions to the sessile-eyed Crus-tacea of New Zealand.- Transactions and Pro-ceedings of the New Zealand Institute 16:249-265. Conlan, K. 1983. The amphipod superfamily Coro-phioidea in the northeastern Pacific region 3. Family Isaeidae: Systematics and distributional ecology.- Publications in Natural Sciences, Na-tional Museum of Natural Sciences, Canada 4: 1-75. Krapp-Schickel, G., & A. A. Myers. 1979. The Med-iterranean species of Gammaropsis Liljeborg (Crustacea, Amphipoda). - Bollettino del Mu-seo Civico di Storia Naturale, Verona 6:441-467. Ledoyer, M. 1982. Crustaces amphipodes gamma-riens familles des Acanthonotozomatidae it Gammaridae.-Faune de Madagascar 59(1): 1-598. Nelson, W. 1981. A new species of the marine am-phi pod genus Gammaropsis from the south-eastern United States (Photidae). -Proceedings of the Biological Society of Washington 93: 1223-1229,3 figs. Reid, D. M. 1951. Report on the Amphipoda (Gam-maridea and Caprellidea) of the coast of tropical West Africa.-Atlantide Report 2: 189-291. Schellenberg, A. 1938. Litorale Amphipoden des tro-pischen Pazifiks. - Kungliga Svenska Veten-skapsakademiens Handlingar (3) 16(6): 105 pp. Shoemaker, C. R. 1942. Amphipod crustaceans col-lected on the Presidential Cruise of 1938.-Smithsonian Miscellaneous Collections 101(11): 1-52. Stebbing, T. R. R. 1888. Report on the Amphipoda collected by H.M.S. Challenger during the years 1873-76.-Report on the Scientific Results of the Voyage of H.M.S. Challenger During the Years 1873-1876, Zoology 29:xxiv and 1737 pp. --, & D. Robertson. 1891. On four new British Amphipoda. - Transactions of the Zoological Society of London 13:31-42. Thomson, G. M. 1897. On two new gammarids from New Zealand.-Annals and Magazine of Nat-ural History, ser. 6, 20:447-451. (JDT) The Reef Foundation, P.O. Box 170, Big Pine Key, Florida 33043; (JLB) Department of Invertebrate Zoology, Na-tional Museum of Natural History, NHB-163, Smithsonian Institution, Washington, D.C. 20560. 

Gammaropsis arawakia, a New Species of Marine Amphipoda (Crustacea) from Jamaica

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Gammaropsis arawakia, a New Species of Marine Amphipoda (Crustacea) from Jamaica

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