Australian Amphipoda: Aoridae

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

Aora mortoni (Haswell, 1879)

Microdeuteropus [sic] mortoni Haswell, 1879b: 339, pl. 22, fig. 2. --Chilton, 1884: 1040.

Microdeuteropus tenuipes Haswell, 1879b: 339, pl. 22, fig. 1. --Chilton, 1884: 1040.

Microdeutopus mortoni. --Haswell, 1882: 264.

Microdeutopus tenuipes. --Haswell, 1882: 264.

Aora mortoni. --Myers & Moore, 1983: 171, figs 1, 7, 8, 13.

Type material. SYNTYPE (probable): AM P3498 [invalid designation of holotype status by Myers & Moore, 1983:171].

Type locality. Port Jackson, New South Wales.

Description. Based on Myers & Moore, 1983:171, figs 1, 7, 8, 13 [Western Port, Victoria].

Head. Rostrum absent or vestigial; Lateral cephalic lobes apically truncate or apically round, anteroventral margin shallowly excavate, scarcely recessed. Antenna 1 flagellum with 21 or more articles; accessory flagellum present and multiarticulate. Antenna 2 with profuse long setae. Labium with fine setae and stout setae. Mandible, palp article 3 longer than 2, posterior margin straight or weakly falcate, mandible palp posterior margin with setae of two distinct lengths, long setae and an understory of much shorter regularly spaced setae.

Peraeon. Sternal spines present, on other pereonites, apically acute. Gnathopod 1 enlarged in males only; coxa unproduced anterodistally, or distinctly produced anterodistally, sub-acute; basis slender, much less than half 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 greatly elongated, as long as or longer than elongate carpus, distally free, produced along posterior margin of carpus, curved, apically acute, 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 without spines; propodus shorter than carpus, anterior margin weakly to moderately setiferous, posterior margin straight or evenly convex, palm absent; dactylus more than 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 longer than propodus, anterior margin not lobate, densely setose; propodus densely setose, palm with robust seta(e) 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 produced into a small spine. Uropod 1 biramous, rami rami subequal, peduncle much longer than broad, distoventral interramal spine shorter than peduncle. Uropod 2 peduncle without distoventral interramal spine or with vestigial spine. Uropod 3 biramous, rami subequal, inner ramus one and one half times length of peduncle.

Habitat. Algae.

Depth zones. Littoral.

Distribution. New South Wales: Port Jackson (Haswell, 1879; Myers & Moore, 1983); Twofold Bay (Hutchings, et al., 1989). Victoria: Western Port (Myers & Moore, 1983). Tasmania: Tinderbox (Myers & Moore, 1983).

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

(Variant) Female (sexually dimorphic characters).

Peraeon. Sternal spines absent. Gnathopod 1 merus not greatly elongated, fused along its entire length with carpus, without posterodistal spine; carpus subequal in length with propodus; propodus subequal in length to carpus or longer than carpus, palm present, palm delimited from posterior margin, margin entire, palm defined by rounded or oblique corner, with robust seta defining palm (?); significantly overlapping palm. Gnathopod 2 moderately to sparsely setiferous; 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).