Australian Amphipoda: Melitae

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

Ceradocus serratus (Bate, 1862) Ceradocus serratus (Bate, 1862).

Megamaera serrata Bate, 1862: 226, pl. 39, fig. 5.

Moera spinosa Haswell, 1879a: 268, pl.10: fig. 5. --Haswell, 1882: 257. --Haswell, 1885: 105, figs. 5-12 [part].

Ceradocus rubromaculatus. --Della Valle, 1893: 720 (in part). --Stebbing, 1906: 431 (in part). Maera spinosa. Stebbing, 1910a: 642.

Ceradocus (Denticeradocus) serrata. --Sheard, 1939: 285, figs 4, 5a-m.

Ceradocus serratus. J.L. Barnard, 1972a: 221, figs 130-131. --Ledoyer, 1979: 66, fig. 36. --Ledoyer, 1982: 440, fig. 165. --Barnard & Barnard, 1983: 616.

Type material. Whereabouts unknown.

Type locality. Flinders and Hummock Islands, Bass Strait, in sea-weed on a sandy beach.

Description. Based on Sheard, 1939: 285-288, figs 4, 5a-m and J.L. Barnard, 1972a: 221, figs 130-131. Head lateral cephalic lobes broad, truncated, with anteroventral notch or slit, anteroventral corner with acute/subacute tooth or subquadrate. Antenna 1 longer than antenna 2; peduncular article 1 not geniculate with article 2, with 3 robust setae along posterior margin or with 4 or more robust setae along posterior margin. Antenna 2 peduncular article 2 cone gland not reaching to end of peduncular article 3. Mandible palp present, well developed, article 3 cone-like, setose on distomedial margin, subequal to article 1, article 2 longer than article 3, article 1 produced distally, shorter than article 2, about twice as long as broad. Maxilla 1 inner plate setose along entire inner margin.

Pereon. Gnathopod 1 not sexually dimorphic; coxa anteroventral corner produced, acute, coxa posteroventral corner notch absent; merus with sharp posterodistal tooth; carpus about 2 x as long as broad; propodus without anterodistal projection, posterodistal margin not swollen, without posterodistal corner. Gnathopod 2 sexually dimorphic; subchelate; left and right gnathopods unequal in size, or left and right gnathopods subequal in size; coxa posteroventral corner notch absent; merus with sharp posteroventral tooth; carpus compressed; propodus without medial depression, without strong concentration of setae, palm acute, straight, sculptured, lined with robust setae, without posteroventral corner; dactylus closing along palm, reaching end of palm. Peraeopod 5 basis posterior margin straight. Peraeopod 5 basis posteroventral corner with acute or subacute process. Peraeopod 6 coxa anterior lobe ventral margin not produced ventrally. Peraeopod 6 basis posterior margin straight. Peraeopod 6 basis posteroventral corner with acute or subacute process. Peraeopod 6 propodus not expanded posterodistally. Peraeopod 7 basis posterior margin straight. Peraeopod 7 basis with posterior margin smooth or minutely castelloserrate, posteroventral corner with acute or subacute process. Peraeopod 7 propodus not expanded posterodistally.

Pleon. Pleonite 1 with dorsal serrations, without dorsodistal spines, not dorsally bicarinate. Pleonite 2 with dorsal serrations, without dorsodistal spines, not dorsally bicarinate. Pleonite 3 with dorsal serrations, without dorsodistal spines, dorsally smooth. Epimeron 1 anteroventral corner without curved spine. Epimera 1-2 posteroventral margin with 1 to 2 large or small spines above spine defining posteroventral corner, or without spines above posteroventral corner. Epimeron 3 posterior margin serrate, posteroventral margin serrate. Urosomite 1 without dorsal carina, without a small dorsal hump, with dorsal serrations, with spines at midline, no conspicuous medial gape, not dorsally bicarinate. Urosomite 1 without posterodorsal spine. Urosomite 2 posterior margin with dorsal midline spine and serrations, without dorsolateral robust setae. Urosomite 3 without dorsal robust setae. Uropod 1 peduncle with basofacial robust seta, without distoventral spur. Uropod 3 exceeding uropods 1 and 2; inner ramus subequal in length to outer ramus; outer ramus long (more than 1.6 x longer than peduncle). Telson cleft. Telson without robust setae on inner margins. Telson each lobe with 2 apical/subapical robust setae or each lobe with 3 or more apical/subapical robust setae, apical conical extension reaching at least halfway along longest seta.

Habitat. Marine; littoral and sublittoral.

Depth zone. Littoral.

Remarks. The population of C. serratus reported by Ledoyer (1979; 1982) from Madagascar is very similar ot the Australian population. The main differences are in the shape of the palm on male G2 and the length of the apical robust setae on the telson (much longer in the Madagascar populations).

Distribution. New Soth Wales: Split Solitary Island; Merimbula; Twofold Bay (all AM). Victoria: Shoreham; Port Phillip Bay (both AM). Tasmania: Flinders and Hummock Islands, Bass Strait (Bate, 1862). South Australia: Spencer Gulf (AM).

Extrinsic distribution. Madagascar.

Australian geographic areas. South-eastern 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'.