Australian Amphipoda: Aoridae

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

Xenocheira seurati Chevreux, 1907: 416. --Chevreux, 1908: 510, figs 26�28. --Schellenberg, 1938b: 86. --Ledoyer, 1984: 41, fig. 19. --Moore, 1988: 712, figs 4�7.

Type material. SYNTYPES: male and female, MNHN Am3811.

Type locality. Mangareva Island, Gambier Islands, French Polynesia, on pearl oysters, 20�25 m depth.

Description. Based on Moore, 1988: 712 � 718, figs 4�7 [Western Australia].

Head. Rostrum absent or vestigial; Lateral cephalic lobes apically round, anteroventral margin shallowly excavate, scarcely recessed. Antenna 1 flagellum with 20 or less articles; accessory flagellum present and with one long and one rudimentary article. Antenna 2 with few long setae. Labium with fine setae only. Maxilla 1 inner plate with 1 long pectinate apical seta. Maxilliped basis without strong flange on anterior margin. Mandible, palp article 3 longer than 2, posterior margin straight or weakly falcate or widest medially, mandible palp posterior margin setae of more than two distinct lengths.

Peraeon. Sternal spines absent. Gnathopod 1 enlarged in both sexes; coxa unproduced anterodistally, or distinctly produced anterodistally, sub-acute; basis robust, half or more as broad as long, without a spine, anterior margin without stridulating ridges, posterodistal margin with setae sparse or absent, anterodistal margin with strong flange, with a weak distomedial lobe or absent; ischium anterior margin with rounded or acute flange, posterior margin with setae sparse or absent; merus not greatly elongated, fused along its entire length with carpus, posterior margin with dense rows of setae, without posterodistal spine; carpus subequal in length with propodus, anterior margin without stridulating ridges, with long dense setae, anterior surface with no spine, with an oblique row of long setae on medial face, posterior margin without spines; propodus subequal in length to carpus, anterior-distal margin densely clothed in long setae, posterior margin straight or evenly convex, palm present, palm delimited from posterior margin, margin entire, palm defined by subquadrate corner, with robust seta defining palm, without spine near base of dactylus; dactylus about half length of propodus, fitting palm. Gnathopod 2 subchelate; basis anterodistal margin without flange, posterodistal margin without robust setae; with few setae along length of basis; carpus subequal with or shorter than propodus, anterior margin lobate, densely setose; propodus densely setose, without robust seta or spine defining palm. Pereopod 6 basis not or weakly produced posterodistally. Pereopod 7 significantly greater than 125% length of pereopod 6.

Pleon. Epimeron 3 posterodistal margin rounded. Uropod 1 biramous, rami inner ramus distinctly longer than outer, peduncle much longer than broad, distoventral interramal spine shorter than peduncle. Uropod 2 peduncle with distoventral interramal spine. Uropod 3 biramous, rami subequal, inner ramus one and one half times length of peduncle. Telson with distal fine setae only.

Habitat. Seagrass, rubble, oyster shells.

Depth zones. Littoral.

Distribution. Western Australia: Cliff Head (Moore, 1988).

Geographic areas. North-western Australia.

Extrinsic distribution. Gambier Islands, Fiji, New Caledonia,.

Peraeon. Gnathopod 1 ischium anterior margin without flange; posterior margin with sparse setae or setae absent; carpus two thirds length of propodus or subequal in length with propodus, with setae sparse or absent; palm defined by rounded or oblique corner; significantly overlapping palm.

Distribution. Western Australia.

Cite this publication as: 'J.K. Lowry, P.B. Berents & R.T. Springthorpe (2001 onwards). Australian Amphipoda: Aoridae. Version 1: 2 October 2000. https://crustacea.net/'. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).

Index