Australian Amphipoda: Melitae

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

Melita oba J.L. Barnard, 1972

Melita oba J.L. Barnard, 1972a: 231 figs 137 (part), 138. --Barnard & Barnard, 1983: 665.

Type material. HOLOTYPE: male, 7.2 mm, WAM 213-68.

Type locality. West of Bunker Bay, Cape Naturaliste, Western Australia, among intertidal algae and rocks.

Description. Based on J.L. Barnard, 1972a: 231 figs 137-138. Head with anteroventral notch or slit (small), anteroventral corner rounded. Antenna 1 longer than antenna 2; peduncular article 1 not geniculate with article 2, shorter than article 2, with 4 or more robust setae along posterior margin; accessory flagellum with 5 articles (about). Antenna 2 peduncular article 2 cone gland not reaching to end of peduncular article 3; article 4 subequal to article 5; flagellum with 11 articles (about). Mandible palp present, well developed, article 3 rectolinear, setose along straight medial margin, longer than article 1, article 2 subequal to article 3 or article 2 shorter than article 3, article 1 not produced, shorter than article 2. Maxilla 1 inner plate with setae mainly terminal.

Pereon. Gnathopod 1 not sexually dimorphic; coxa anteroventral corner produced, rounded, 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 nearly transverse, 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 with medial depression, setose, palm extremely acute or broadly rounded, convex, smooth, without robust setae, without posterodistal robust setae, without posteroventral corner; dactylus closing across medial surface of propodus, 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 slightly produced, rounded. Peraeopod 6 basis posterior margin convex (slighlty). 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, posteroventral corner with small acute spine, posteroventral margin smooth or serrate. 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, with two groups of 1-3 small dorsolateral robust setae. Urosomite 3 without dorsal robust setae. Uropod 1 peduncle with basofacial robust seta, without distoventral spur. Uropod 3 greatly exceeding uropods 1 and 2; inner ramus scale-like, much shorter than outer ramus; outer ramus medium length (1.1 to about 1.5 x longer than peducle) or long (more than 1.6 x longer than peduncle), 2-articulate. Telson cleft. Telson without robust setae on inner margins. Telson each lobe with 2 apical/subapical robust setae, apical conical extension reaching scarcely one third along longest seta.

Habitat. Estuarine; living intertidally among algae and rocks.

Depth zone. Littoral.

Distribution. Western Australia: Cheyne Beach; Jervois Bay, Cockburn Sound; Sugarloaf Rock and west of Bunker Bay, Cape Naturaliste; Middleton Beach, Albany (all J.L. Barnard, 1972a).

Australian geographic areas. South-western Australia.

Type material. HOLOTYPE: male, 7.2 mm, WAM213-68.

Pereon. Gnathopod 2 carpus short; propodus without medial depression, without strong concentration of setae, palm acute, straight; dactylus closing along palm, apically acute/subacute. Peraeopod 6 coxa anterior lobe ventral margin slightly produced, truncated.

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. https://crustacea.net'.