STUDIES ON THE CRUSTACEA OF THE TURKS AND CAICOS ISLANDS, BRITISH WEST INDIES I. FOUR NEW MARINE ISOPOD CRUSTACEANS FROM THE VICINITY OF PINE CAY. BRIAN KENSLEyt AND RICHARD W. HEARD! IDepartment of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, D.C. 20560 2Invertebrate Zoology Section, Gulf Coast Research Laboratory, P.O. Box 7000, Ocean Springs, Mississippi 39564 ABSTRACT Four undescribed species of shallow-water marine isopods were recently collected in the vicinity of Pine Cay in the western Caicos Islands. These are described and include the anthurid Licranthura tuberculata, possessing a tuberculate third article of the antenna and a rounded distolateral angle of the uropodal exopod; the anthurid Mesanthura spongicola, which has a distinctive color pattern, distinctly attenuated body, and 5-7 spines on the third article of the mandibular palp; the paranthurid Califanthura minuta, a tiny (1.6 nun) species having a reduced, triangular uropodal exopod; and the stenetriid asellote Stenetrium caicosensis, which has a pronounced lobe on the mems of pereopod 1 in the male. The fauna of the Turks and Caicos Islands, British West Indies, is poorly documented, especially for many marine invertebrate groups including the Isopoda. During the course of participating in the Turks and Cajcos Coral Reef Ecology Program sponsored by the Oakleigh L. Thome Foundation, the second author collected iso- pods from a variety of shallow-water marine habitats, mainly around Pine Cay and Fort George Cay. Fine mesh kicknets, yabby pumps, an Ockelmann dredge, and light traps were all used in this collection, with SCUBA at the deeper stations. Four undescribed marine species found during the survey and their descriptions are the subject of this report. While the marine isopods of the general Caribbean and Bahamian region have been broadly dealt with in Kensley and Schotte (1989), this is the first of a series of reports (see Schotte and Heard 1991, Schotte et al1991) dealing with isopods specifically from the Turks and Caicos Islands. Family Anthuridae Licranthura tuberculata, new species Figs. 1-3 Material. HOLOTYPE, USNM 243474, female t13.2 mm, PARATYPE, USNM 243475, male tl3.2 mm, from yellow sponge, 37-40 m, 10 Nov 1988. Description. Female: Body slender, about 12 times longer than wide. Faint red-brown pigmentation dorsally on pereonites 2-6. Body proportions: C < 1 > 2 = 3 < 4 with 5 or 6 distal plumose setae. Uropodal endopod = 5 > 6 > 7 3 < 4 > 5 > 6 > 7 < P. Pleonite 6 dorsally free, posterior margin bilobed. Telson with posterior margin broadly rounded, with 2 pairs of short and long apical setae mesially. Antennular flagellum of 4 articles, subterminal article with 1 aesthetasc, terminal article with 2 aes- thetascs. Antennal flagellum of 4 setose articles. Mandi- bular palp of 3 articles, article 2 longest and broadest, with single strong distal seta, article 3 having 5 - 7 distal spines; lamina dentate with 5 serrations; molar reduced to rounded boss. Maxilla with 6 distal spines. Maxilliped lacking endite, palp of 3 articles, terminal article semi- circular in outline, with 7 setae on mesial margin. Pereopod 1 subchelate, carpus triangular, posterodis- tally rounded; propodus moderately expanded, length about 2.5 times greatest width, palm sinuous, bearing few setae; unguis subequal in length to rest of dactylus. Pereopod 2, propodus with anterior length almost 3 times greatest width, with posterior margin bearing numerous scales plus tricuspid posterodistal spine; dactylus with 2 low proximal teeth on posterior margin, unguis about half length of rest of dactylus. Pereopods 4 - 7, carpi with anterior margin shorter than posterior, with short pos- terodistal spine; propodi with fringed scales on posterior margin plus 2 stout fringed setae and tricuspid spine posterodistally; unguis about one-third length of rest of dactylus. Pleopod 1 exopod operculiform, about 3.5 times wider than endopod, latter shorter than exopod, with 6 distal plumose setae. Uropodal endopod distally rounded, length about 1.5 times basal width; exopod reaching beyond base of endopod, apically acute, with shallow distal emargination in lateral margin. Color pattern. Red-brown patches of chromato- phores on dorsum of cephalon, all pereonites, pleon, telson, and uropods, those on pereonites and pleon having elongate unpigmented median area. Remarks. Of the eight known species of M esanthura from the western North Atlantic, M. spongicola is most similar to M. bivittata Kensley, 1987, from Belize and M. looensis Kensley & Schotte, 1987, from the Florida Keys. The new species can be separated from M. bivittata by the presence of 5 - 7 spines on article 3 of the mandibular palp and pereopods 2 - 6 each having a stout tricuspid sensory spine at the posterodistal angle of the propodus. The distinctly more elongate body form and the dorsal pigment pattern distinguish M. spongicola from M. looensis. Pereonite 7 of M. spongicola has the pigment patch in a thick irregular U-shape, whereas the pigment in this area in M. looensis is in the shape of an acute triangle or tapers anteromedially. Collection data indicate that M. spongicola is associ- ated with, and lives in a yellow tube sponge, Verongia sp. Although numerous benthic and epibenthic samples, which represented a variety of substrata and over 10 other species of sponges, were taken along the fringing reef- face off Pine Cay, M. spongicola was found to occur only with the yellow tube sponge. Specimens were found in six of the eight specimens of Verongia examined during the fall (Oct-Nov) of 1988 and 1989; however, during the spring (April- May) of 1989 and 1990 no specimens of M. spongicola were found in over 20 yellow tube sponges from the same collecting area. Of the approximately 30 described species of Mesanthura, only three, viz. M. albinotata Thompson, 1951, M. bipunctata Thompson, 1951, and M. protei Kensley, 1980, have been collected with, or found in sponges (See Negoescu & Wagele 1984). Etymology. The specific epithet, meaning 'sponge dweller', refers to the fact that all the specimens of this species were taken from sponges. Family Paranthuridae Califanthura minuta, new species Fig. 5 Material. HOLOTYPE, USNM 243271, ovig. fe- male tl 1.6 mm, PARATYPES, USNM 243272, 2 non- ovig. females tl1.6 mm, off Pine Cay, inner fringing reef, in coarse sand and rubble, 1.5 m, 3 Nov 1988. PARA- TYPE, USNM 243273, non-ovig. female cl 1.6 mm, off Pine Cay, in coarse sand and rubble, 5 m, 16 Nov 1989. PARATYPE, GCRL 1148, 1 non-ovig. female, 1.6 mm, off Pine Cay, back of fringing reef in coarse sand and rubble, 4 m, 16 Apr 1989. Description. Body proportions: C < 1 = 2 < 3 < 4 > 5 > 6 > 7. Cephalon with low rounded rostrum; eyes well pigmented, consisting of 6 - 8 ommatidia each. Pereonite 7 about one-sixth length of pereopod 6, lacking legs. Pleonites 1 - 5 fused; pleonite 6 dorsally indistinguisha- bly fused with telson. Latter tapering posteriorly to broadly rounded posterior margin. Antennular peduncle with basal article longest and broadest; article 2 shorter than article 3; flagellum of 2 short articles, distal article bearing several simple setae plus 2 aesthetascs. Antennal peduncle with article 3 about half length of article 4, which in turn about half length of article 5; flagellum consisting of single setose article. Maxilla having about 12 distal serrations. Pereopod 1, carpus distally rounded; propodus broad, expanded, with rounded lobe at proxi- mal end of palm, having 3 stout basally situated setae on mesial surface, palm with lateral convex flange bearing few setae. Pereopod 2, propodus barely inflated, with 4 short spines on posterior margin. Pereopod 6, carpus with anterior margin shorter than posterior, latter bearing 2 distal spines on posterior margin; propodus about 2.5 times longer than wide, with single strong posterodistal spine. Pleopod 1, endopod elongate, slender, with 3 distal plumose setae; exopod broad, operculiform, with about 8 plumose setae on laterodistal margin. Uropodal endo- Fig. 4. Mesallthura spollgicola, new species; A, Non-ovigerous female in dorsal view; B, antenna; C, antennule; D, mandible; E, maxilla; F, maxllltped; G, pereopod 1; H, pereopod 2; I, pereopod 7, distal propodus and dactylus; K, pleopod 1; L, uropod. pod ovate, distal margin setose; exopod short, narrowly triangular, distally acute, barely reaching level of mesio- distal margin of protopod. Remarks. Poore (1984) clarified the diagnoses of four seemingly closely related paranthurid genera that lack a seventh pereopod in the adult, of which Califan- thura is one. The five previously decribed species of Cal- ifanthura are characterized by having pleonites 1-5 fused and generally lacking dorsal folds marking this fusion (see Poore 1984:699). None of these possesses a short triangular uropodal exopod and an evenly tapering tel- son, nor are any of them mature at the small size (1.6 mm) seen in C. minuta. Etymology. The specific epithet, the Latin for little or tiny, refers to the small size (1.6 mm) of the adult. Family Stenetriidae Stenetrium caicosensis, new species Figs. 6-7 Material. HOLOTYPE, USNM 243476, male tl 5.0 mm, PARATYPES, USNM 243477, 2 males tl 4.3 - 5.0 mm,5 ovig. females tl3.9 - 4.5 mm, 11juvs., GCRL 1150, 1 male 4.3 mm, 1 ovig. female 4.8 mm, Fort George Cay, Neogoniolithon washings, 0.5 m, 18 Apr 1988. PARA- TYPE, USNM 243478, male tl 5.2 mm, Crab Hole Cay, Caicos Bank off Pine Cay, 15 Apr 1988. Description. Male: Body about 3.5 times longer than greatest width. Cephalon with dorsolateral eyes large, well pigmented; anterolateral lobe acutely triangular; frontal margin faintly concave; rostrum rectangular, anterior margin truncate. Anterolateral lobes of pere- onites 1-3 acute, of 4-7 right-angled to rounded; postero- lateral lobes of pereonites 6 and 7 acute. Pleotelson wider than long, lateral margins each with 4 serrations, posteri- ormost forming strong tooth; posterior margin between uropodal bases gently convex. Antennule with basal article widest and longest, article 2 about half length of 3; flagellum of 11 articles, single aesthetasc on each of 8 distal articles. Antenna almost as long as body, peduncle articles 1 and 2 short, subequal, latter with setose scale, article 3 very short, articles 4 and 5 slender, elongate, subequal, each longer than 3 proximal articles together. Mouthparts typical of genus, as figured. Maxilliped endite with 6 coupling hooks on mesial margin. Pereopod 1 of mature male with posterior surfaces of ischium, merus, carpus, propodus and dactylus bearing dense elongate setae; merus with broad apically subacute lobe produced from distal half of posterior margin; carpus subequal in length of merus (excluding posterior lobe); propodus anterior length about 2.5 times greatest width, with distally directed spine-like process in distal half of posterior margin; dactylus curved, club-shaped, reach- ing to base of propodus, lacking distal claw or unguis. Pereopods 2 - 7 similar, meri with anterodistal angle produced and bearing stout seta; carpi roughly rectangu- lar, with few short spines on posterior margin; propodi subequal in length to, about half width of carpus, with 6 spines on posterior margin; dactyli biunguiculate, 2 ungui equally strong; slender accessory spines on poste- rior margin. Pleopod 1, rami tapering, distally rounded, distolateral margins setose. Pleopods 2-4 typical of genus. Uropod with basis slightly shorter than endopod; exopod three-fourths length of endopod. Female: Pereopod 1, basis bearing 5 stout distal setae on anterior margin; ischium with few setae on posterior surface; merus with anterodistal angle produced, bearing stout seta; carpus with numerous setae on posterior surface, anterodistal angle produced into acute lobe; propodus with palm separated from posterior margin by strong fringed spine, palm bearing 5 slender fringed setae; dactylus bearing row of short fringed spines on posteriodistal margin, unguis about one-fourth length of rest of dactylus. Pleonal operculum longer than basal width, subapically slightly pinched, distally rounded. Color pattern. Red-brown scattering of chromato- phores between eyes, on pereonites 1 and 2, broad band on 3, absent on 4, broad band on 5, scattering on 6 and 7, broad basal band with lateral lobes on pie on. Remarks. Of the four Caribbean species of Sten- etrium having reniform eyes (See Kensley & Schotte 1989:100), S. caicosensis most closely resembles S. bowmani Kensley, 1984, from Belize and Mexico, espe- cially in the shape of the cephalon and pleon. The two species can easily be separated, however, by the color pattern (the chromatophores are more evenly and densely spread over the dorsum of S. bowmani), by the number of coupling hooks on the maxillipedal endite (four in S. bowmani, six in S. caicosensis), by the shape of pereopod 1 of the male (S. bowmani possesses an expanded propodus with a trilobed palm, while S. caicosensis has a broad lobe on the posterior surface of the merus), and by the more strongly produced acute anterodista1lobe on the carpus of pereopod 1 of S. caicosensis. Etymology. The specific name is derived from the type locality, viz. the Caicos Islands. Collection of the material reported in this study was sponsored by the Oakleigh L. Thome Foundation through a grant to Stephen Spotte, whose interest and support are greatly appreciated. We thank Oakleigh B. Thome, members and employees of the Meridian Club, and the Turks and Caicos Government for support and encour- agement. Patricia Bubucis, Cherie S. Heard, Roy R. Manstan, Jerry McLelland, and Stephen Spotte helped in the field and provided other technical assistance. We are grateful to Marilyn Schotte of the Smithsonian institu- tion, who did much of the preliminary sorting and identification of the samples. This is Contribution No. 5 of the Turks and Caicos Coral Reef Ecology Program. Fig. 5. Califanthura minuta, new species, female: A, cephalon, antennules, and antennae; B, maxUla; C, pereopod 1; D, pereopod 2; E, pereopod 6; F, pleon and pleotelson; G, pleopod 1; H, uropod. Fig. 6. Stenetrium caicosensis, new species: A, whole animal in dorsal view; B, mandible; C, maxiUa 1; D, maxiUa 2; E, antennule; F, maxillUped; G, operculum, female; H, uropod; I, pleopod 1 male; J, pleopod 2 male; K, pleopod 3; L, pleopod 4. Kensley, B. 1980. Anthuridean isopod crustaceans from the International Indian Ocean Expedition, 1960-1965, in the Smithsonian Collections. Smithson. Contrib. Zool. 304:1-37. _____ . 1984. The Atlantic Barrier Reef &osystem at Carrie Bow Cay, Belize, m. New Marine Isopoda. Smithson. Contrib. Mar. Sci. 24:1-81. 1987. Further records of marine isopod crustaceans from the Caribbean. Proc. Biol. Soc. Wash. 100(3):559-577. & M. Schotte. 1987. New records of isopod Crustacea from the Caribbean, the Florida Keys, and the Bahamas. Proc. Biol. Soc. Wash. 100(1):216-247. ___ & . 1989. Guide to the marine isopod crustaceans of the Caribbean. Smithsonian Institution Press, Washington, D.C. and London, 308 pp. Negoescu, I. & J.-W. Wagele. 1984. 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