Australian Amphipoda: Aoridae

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

Microdeutopus varietensis Moore, 1987: 776, figs 1, 2.

Type material. HOLOTYPE: male. 6 mm, AM P36999. PARATYPES: female, AM P37000; 4 males, 5 females, BMNH 1986:414.

Type locality. Variety Bay, outside Bruny Island, Tasmania, from Macrocystis pyrifera holdfasts, 6 to 8 m depth.

Description. Based on Moore, 1987: 776, figs 1�2 [Bruny Island, Tasmania].

Head. Rostrum absent or vestigial; Lateral cephalic lobes apically round, anteroventral margin shallowly excavate, scarcely 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 longer than 2, posterior margin straight or weakly falcate or widest medially, mandible palp posterior margin with setae of two distinct lengths, long setae and an understory of much shorter regularly spaced setae.

Peraeon. Sternal spines absent. Gnathopod 1 enlarged in males only; 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 strong flange, 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; carpus one and one third to one and one half 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 with stout spine or spines, one spine; propodus shorter than carpus, anterior margin weakly to moderately setiferous, posterior margin sinuous or irregular with proximal lobe, palm absent; dactylus about half length of propodus. 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 not lobate, moderately to sparsely setiferous; propodus moderately to sparsely setose, palm with robust seta(e) 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 produced into a small spine. Uropod 1 biramous, rami rami subequal, peduncle slightly longer than broad, distoventral interramal spine longer than peduncle. Uropod 2 peduncle without distoventral interramal spine or with vestigial spine. Uropod 3 biramous, rami subequal, inner ramus subequal with length of peduncle. Telson with distal fine setae only.

Habitat. In holdfasts of Macrocystis pyrifera.

Depth zones. Littoral.

Distribution. Tasmania: Variety Bay, outside Bruny Island (Moore, 1987).

Geographic areas. South-eastern Australia.

Peraeon. Gnathopod 1 coxa unproduced anterodistally, or distinctly produced anterodistally, sub-acute; without posterodistal spine; carpus two thirds length of propodus or subequal in length with propodus, posterior margin without spines; propodus subequal in length to carpus or longer than carpus, palm present, palm delimited from posterior margin, margin entire, palm defined by subquadrate corner, with robust seta defining palm; significantly overlapping palm.

Pleon. Epimeron 3 posterodistal margin rounded.

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