Australian Amphipoda: Melitae

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

Elasmopus echo J.L. Barnard, 1972

Elasmopus echo J.L. Barnard, 1972a: 255, figs 148-149. --Berents, 1983: 136, fig. 27.

Type material. HOLOTYPE: male, 14.0 mm, WAM 41-69.

Type locality. About 5 kms south-west of Bunbury, Western Australia, 20 m depth.

Description. Based on J.L. Barnard, 1972a: 255, figs 148-149. Head lateral cephalic lobes broad, truncated, with anteroventral notch or slit, anteroventral corner with acute/subacute tooth. 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 (slightly), with 2 robust setae along posterior margin; accessory flagellum with 4 articles. Antenna 2 peduncular article 2 cone gland reaching at least to end of peduncular article 3; article 4 longer than article 5. Mandible palp present, well developed, article 3 rectolinear, with setae mostly terminal, shorter than article 1, article 2 shorter than article 3, article 1 curved, swollen distally, longer than article 2, at least 3 x 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 absent; 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, without 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, setose, palm acute, concave, sculptured, defined by posterodistal robust setae, without posteroventral corner; dactylus closing along palm, reaching end of palm, apically blunt. Peraeopod 5 basis posterior margin concave (slighlty). Peraeopod 5 basis posteroventral corner serrate. Peraeopod 6 coxa anterior lobe ventral margin slightly produced, rounded. Peraeopod 6 basis posterior margin concave. Peraeopod 6 basis posteroventral corner serrate. Peraeopod 6 propodus not expanded posterodistally. Peraeopod 7 basis posterior margin convex. Peraeopod 7 basis with posterior margin castelloserrate, posteroventral corner with acute or subacute process. Peraeopod 7 propodus not expanded posterodistally.

Pleon. Pleonite 1 without dorsal serrations, without dorsodistal spines, dorsally bicarinate. Pleonite 2 without dorsal serrations, without dorsodistal spines, dorsally bicarinate. Pleonite 3 without dorsal serrations, without dorsodistal spines, dorsally bicarinate. 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 serrate. Urosomite 1 without dorsal carina, without a small dorsal hump, without dorsal serrations, without spines or gape, 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. Uropod 3 subequal or slightly exceeding length of uropods 1 and 2; inner ramus subequal in length to outer ramus; outer ramus medium length (1.1 to about 1.5 x longer than peducle). 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. Marine.

Depth zone. Littoral (3 to 25 m).

Distribution. Queensland: Lizard Island (Berents, 1983); Peel Island; Flat Rock, North Stradbroke Island (both AM). New South Wales: Cook Island (AM). Western Australia: south-west of Bunbury (J.L. Barnard, 1972a).

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

Type material. HOLOTYPE: male, 14.0 mm, WAM _____.

Pereon. Gnathopod 2 carpus long; straight, without robust setae; apically acute/subacute.

Pleon. Depth zone. Littoral (about 20 m).

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

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'.