Australian Amphipoda: Melitae

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

Maera octodens Sivaprakasam, 1968

Maera octodens Sivaprakasam, 1968: 36, fig. 2. --Surya Rao, 1972: 196. --Ledoyer, 1978: 278, fig. 31. --Ledoyer, 1979: 80, fig. 45. --Ledoyer, 1982: 532, fig. 200. --Berents, 1983: 128, fig. 22. --Myers, 1985: 112, fig. 88.

Type material. HOLOTYPE: male, ZSI.

Type locality. Appa Island, Gulf of Mannar, India.

Description. Based on Sivaprakasam, 1968: 36, fig. 2, Berents, 1983: 128, fig. 22 and Myers, 1985: 112, fig. 88. 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 or shorter than article 2, with 1 robust seta on posterior margin or with 2 robust setae along posterior margin; flagellum with 18 articles; accessory flagellum with 4 articles (about). Antenna 2 peduncular article 2 cone gland not reaching to end of peduncular article 3; article 4 longer than article 5; flagellum with 6 articles. Mandible palp present, well developed, article 3 rectolinear, with setae mostly terminal, longer than article 1, article 2 longer than article 3, article 1 not produced, subequal to article 2, about twice as long as broad. Maxilla 1 inner plate with setae mainly terminal.

Pereon. Gnathopod 1 not sexually dimorphic; coxa anteroventral corner produced, acute, coxa posteroventral corner notch present; merus without posterodistal tooth; carpus about 2 x as long as broad; propodus without anterodistal projection, posterodistal margin not swollen, palm acute, straight, defined by posterodistal corner, defined by posterodistal robust setae. Gnathopod 2 sexually dimorphic; subchelate; left and right gnathopods unequal in size; (larger) merus with sharp posterventral tooth; compressed; palm angle acute, straight, posterodistal tooth absent, without robust setae; dactylus apically blunt; (smaller) merus with sharp posterventral tooth; long; palm straight, without posteroventral tooth. Peraeopod 5 basis posterior margin straight. Peraeopod 5 basis posteroventral corner narrowly rounded or subquadrate. Peraeopod 6 basis posteroventral corner with acute or subacute process, or narrowly rounded or subquadrate. Peraeopod 6 propodus not expanded posterodistally. Peraeopod 7 basis posterior margin convex (slighlty). Peraeopod 7 basis with posterior margin smooth or minutely castelloserrate, posteroventral corner with acute or subacute process or narrowly rounded or subquadrate. 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 serrate, posteroventral corner with small acute spine, 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 3 inner ramus shorter than outer ramus, or subequal in length to outer ramus; outer ramus long (more than 1.6 x longer than peduncle), 1-articulate. Telson cleft. Telson without robust setae on inner margins. Telson each lobe with 1 apical/subapical robust seta, apical conical extension reaching scarcely one third along longest seta.

Habitat. Marine; living in coral rubble.

Depth zone. Littoral.

Remarks. The female is not known.

Distribution. Queensland: Lizard Island, Great Barrier Reef (Berents, 1983).

Extrinsic distribution. Eastern India; Mauritius; Madagascar; Fiji.

Australian geographic areas. North-eastern Australia.

(Variant) Female (sexually dimorphic characters).

Pereon. Gnathopod 2 left and right gnathopods subequal in size.

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.'.