Australian Amphipoda: Melitae

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

Melita matilda J.L. Barnard, 1972

Melita matilda J.L. Barnard, 1972a: 231, figs 136-137. --Barnard & Barnard, 1983: 665.

Type material. HOLOTYPE: male, 8.9 mm, WAM 225-68.

Type locality. Matilda Bay, Swan River, Western Australia.

Description. Based on J.L. Barnard, 1972a: 235, figs 136-137. 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 (distal); flagellum with 24 articles (about); accessory flagellum with 5 articles. Antenna 2 peduncular article 2 cone gland not reaching to end of peduncular article 3; article 4 subequal to article 5. 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, shorter than article 2. Maxilla 1 inner plate with setae mainly terminal.

Pereon. Gnathopod 1 not sexually dimorphic; coxa anteroventral corner 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 swollen, palm obtuse, 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, without strong concentration of setae, palm acute, straight, smooth, without robust setae, defined by posterodistal robust setae, without posteroventral corner; dactylus closing across medial surface of propodus, reaching end of palm, apically acute/subacute. Peraeopod 5 basis posterior margin straight. Peraeopod 5 basis posteroventral corner narrowly rounded or subquadrate. Peraeopod 6 coxa anterior lobe ventral margin strongly produced, rounded. Peraeopod 6 basis posterior margin subsigmoidal (slighlty). Peraeopod 6 basis posteroventral corner insignificant. Peraeopod 6 propodus not expanded posterodistally. Peraeopod 7 basis posterior margin subsigmoidal (slighlty). Peraeopod 7 basis with posterior margin smooth or minutely castelloserrate, posteroventral corner insignificant. 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 strongly produced 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, 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 long (more than 1.6 x longer than peduncle), 2-articulate. Telson cleft. Telson without robust setae on inner margins. Telson each lobe with 3 or more apical/subapical robust setae, apical conical extension reaching scarcely one third along longest seta.

Habitat. Estuarine.

Depth zone. Littoral.

Distribution. New South Wales: Richmond River, Ballina; Split Solitary Island; Port Jackson; Botany Bay; Wallis Lake (all AM). Western Australia: Bunbury (AM); Swan River (J.L. Barnard, 1972a).

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

(Variant) Female (sexually dimorphic characters).

Pereon. Gnathopod 2 carpus short; propodus without medial depression, with sparse robust setae; dactylus closing along palm.

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.'.