Australian Amphipoda: Melitae

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

Elasmopus natashae Calaher & Lowry, mss

Type material. HOLOTYPE: male, 7.1 mm, AM P60604. PARATYPES: female, AM P60605; 3 specimens, AM P60606; 14 specimens, AM P60607.

Type locality. Green Point, Pearl Beach, New South Wales (33º32.6'S 151º18.5'E), coralline algal turf, rocky shore at low tide mark.

Description. Based on holotype male, AM P60604 and paratype female, AM P60605. Head lateral cephalic lobes broad, truncated, with anteroventral notch or slit, anteroventral corner subquadrate. Antenna 1 longer than antenna 2; peduncular article 1 not geniculate with article 2, subequal in length to article 2, without robust setae along posterior margin; flagellum with 27 articles (about); 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 8-9 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 not produced, shorter than article 2, about as long as broad. 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 acute, convex or straight, 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 subquadrate posteroventral corner; carpus compressed; propodus without medial depression, with strong setal bunch, palm extremely acute, convex, smooth, without robust setae, without posterodistal robust setae, without posteroventral corner; dactylus closing along palm, not reaching end of palm, apically blunt. Peraeopod 5 basis posterior margin convex (slightly). Peraeopod 5 basis posteroventral corner narrowly rounded or subquadrate. Peraeopod 6 coxa anterior lobe ventral margin slightly produced, truncated. Peraeopod 6 basis posterior margin concave. Peraeopod 6 basis posteroventral corner narrowly rounded or subquadrate. Peraeopod 6 propodus not expanded posterodistally. Peraeopod 7 basis posterior margin convex. Peraeopod 7 basis with posterior margin smooth or minutely castelloserrate, posteroventral corner 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 smooth or serrate (minutely), 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 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 3 or more apical/subapical robust setae, apical conical extension reaching scarcely one third along longest seta.

Habitat. Marine; living among coralline algae on rocky shore at the low tide mark.

Depth zone. Littoral (subtidal).

Remarks. Compare with E. meneurte and E. yunde, both from south-western Australia.

Distribution. New South Wales: Green Point, Pearl Beach; Box Head, Broken Bay (both AM).

Australian geographic areas. South-eastern Australia.

Pereon. Gnathopod 2 without strong concentration of setae; reaching end of palm, apically acute/subacute.

Pleon. Remarks. Compare to E. meneurte and E. yunde, both from south-western Australia.

Distribution. New South Wales: Green Point, Pearl Beach (AM).

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'.