Australian Amphipoda: Melitae

J.K. Lowry, P.B Berents & R.T. Springthorpe

Elasmopus hooheno J.L. Barnard, 1970

Elasmopus hooheno J.L. Barnard, 1970: 120, fig. 70. --J.L. Barnard, 1971: 71, figs 33-35. --Ledoyer, 1972: 217, pls 35-36. --Ledoyer, 1978: 269. --Ledoyer, 1979: 69, fig. 40. --Ledoyer, 1982: 470, fig. 174b, 177. --Barnard & Barnard, 1983: 628. --Berents, 1983: 116, fig.13. --Myers, 1997: 109.

Type material. HOLOTYPE: male, 4.3 mm, BMH 7270.

Type locality. Kawela Bay, Oahu, Hawaii, among Sargassum, other algae, rocks, coral.

Description. Based on male and female, AM P30107. Head lateral cephalic lobes broad, truncated, with anteroventral notch or slit, anteroventral corner rounded. Antenna 1 longer than antenna 2; peduncular article 1 not geniculate with article 2, subequal in length to article 2, with 1 robust seta on posterior margin; flagellum with 13 articles; accessory flagellum with 2 articles. Antenna 2 peduncular article 2 cone gland reaching at least to end of peduncular article 3; article 4 subequal to article 5; flagellum with 6 articles. Mandible palp present, well developed, article 3 strongly falcate, setose along concave medial margin, longer than article 1, article 2 longer than article 3, article 1 produced distally, shorter than article 2, about as long as broad or about twice as long as broad. Maxilla 1 inner plate with setae mainly terminal.

Pereon. Gnathopod 1 not sexually dimorphic; coxa anteroventral corner produced, rounded or not produced, coxa posteroventral corner notch absent; merus without posterodistal tooth; carpus about 2 x as long as broad; propodus without anterodistal projection, posterodistal margin not swollen, palm acute, convex, defined by posterodistal corner, defined by posterodistal robust setae. Gnathopod 2 sexually dimorphic; subchelate; left and right gnathopods subequal in size; coxa posteroventral corner notch absent; merus with sharp posteroventral tooth; carpus compressed; propodus without medial depression, without strong concentration of setae, palm acute, straight or concave, sculptured, with sparse robust setae, without posterodistal robust setae, defined by posteroventral tooth; dactylus closing along palm, reaching end of palm, apically blunt. Peraeopod 5 basis posterior margin straight. Peraeopod 5 basis posteroventral corner broadly rounded. Peraeopod 6 coxa anterior lobe ventral margin strongly produced, rounded. Peraeopod 6 basis posterior margin straight. Peraeopod 6 basis posteroventral corner broadly rounded. Peraeopod 6 propodus not expanded posterodistally. Peraeopod 7 basis posterior margin convex. Peraeopod 7 basis with posterior margin smooth or minutely castelloserrate, posteroventral corner broadly rounded. Peraeopod 7 propodus not expanded posterodistally.

Pleon. Pleonite 1 without dorsal serrations, without dorsodistal spines, not dorsally bicarinate. Pleonite 2 without dorsal serrations, without dorsodistal spines, not dorsally bicarinate. Pleonite 3 without dorsal serrations, without dorsodistal spines, dorsally smooth. Epimeron 1 anteroventral corner without curved spine. Epimera 1-2 posteroventral margin without spines above posteroventral corner. Epimeron 3 posterior margin smooth or serrate (minutely), posteroventral corner subquadrate, posteroventral margin smooth. Urosomite 1 without dorsal carina, without a small dorsal hump, without dorsal serrations, without spines or gape, not dorsally bicarinate. Urosomite 1 without posterodorsal spine. Urosomite 2 posterior margin smooth, without dorsolateral robust setae. Urosomite 3 without dorsal robust setae. Uropod 1 peduncle with basofacial robust seta, without distoventral spur. Uropod 3 subequal or slightly exceeding length of uropods 1 and 2; inner ramus shorter than outer ramus; outer ramus short (shorter than or subequal to peducle), 2-articulate (minute). Telson cleft. Telson without robust setae on inner margins. Telson each lobe with 2 apical/subapical robust setae, apical conical extension absent.

Habitat. Marine; Marine; living in algae, coral rubble and reef rocks.

Depth zone. Littoral (intertidal).

Distribution. Queensland: Lizard Island, Great Barrier Reef (Berents, 1983). Western Australia: Cocos (Keeling) Islands (Berents, 1983).

Extrinsic distribution. Madagascar; Mauritius; Hawaiian Islands; Western Samoa.

Australian geographic areas. North-eastern Australia, or North-western Australia.

(Variant) Female (sexually dimorphic characters).

Pereon. Gnathopod 2 straight, smooth, defined by posterodistal robust setae; apically acute/subacute.

Pleon. Depth zone. Littoral.

Cite this publication as: 'J.K. Lowry, P.B Berents & R.T. Springthorpe (2000 onwards). Australian Amphipoda: Melitae Descriptions, Illustrations, Identification and Information Retrieval. Version: 2 October 2000.'.