Australian Amphipoda: Aoridae

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

Xenocheira fasciata Haswell, 1879

Xenocheira fasciata Haswell, 1879a: 272, pl. XI, fig. 6a-c. --Haswell, 1885: 105, pl. XVI, figs 1-3. --Stebbing, 1906: 624. --Moore, 1988: 706, figs 1-3.

not Xenocheira fasciata. --K.H. Barnard, 1931: 125, fig. 4a, b.--Pirlot, 1938: 335, fig. 150.

Type material. SYNTYPE (probable): AM P25466 (invalid designation of holotype status by Moore, 1988).

Type locality. Port Jackson, New South Wales.

Description. Based on Moore, 1988: 706-712, figs 1-3 [Tasmania].

Head. Rostrum absent or vestigial; Lateral cephalic lobes apically truncate or apically round, anteroventral margin moderately excavate, moderately recessed. Labium with fine setae and stout setae. Maxilla 1 inner plate with 1 long pectinate apical seta. Maxilliped basis without strong flange on anterior margin. Mandible, palp article 3 subequal to 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, rounded; 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 flange weak or absent, with a weak distomedial lobe or absent; ischium anterior margin without flange, posterior margin with setae sparse or absent; merus not greatly elongated, fused along its entire length with carpus, posterior margin with sparse setae or setae absent, without posterodistal spine; carpus one third length of propodus, anterior margin without stridulating ridges, with setae sparse or absent, anterior surface with no spine, without an oblique row of long setae on medial face, posterior margin without spines; propodus longer than carpus, anterior margin weakly to moderately setiferous, posterior margin straight or evenly convex, palm present, palm delimited from posterior margin, margin forming a narrow sinus, palm defined by strong posterodistal spine, without 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 less than 125% length of pereopod 6.

Pleon. Epimeron 3 posterodistal margin rounded. Uropod 1 biramous, rami rami subequal, 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. Among Macrocystis pyrifera holdfasts.

Depth zones. Littoral.

Distribution. New South Wales: Port Stephens (Moore, 1988); Port Jackson (Haswell, 1879); Twofold Bay (Hutchings, et al., 1989). Victoria: Western Port; Corner Inlet; Crib Point (Moore, 1988). Tasmania: south-western Bass Strait; Variety Bay, Bruny Island (Moore, 1988). South Australia: Upper Spencer Gulf (Hutchings, et al., 1993).

Geographic areas. South-eastern Australia, or Southern Australia.

(Variant) Female (sexually dimorphic characters).

Peraeon. Gnathopod 1 carpus two thirds length of propodus, with an oblique row of long setae on medial face (?); anterior margin weakly to moderately setiferous (?), margin entire, palm defined by subquadrate corner, with robust seta defining palm; dactylus less than half length of propodus, significantly overlapping palm. Gnathopod 2 propodus moderately to sparsely setose.

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