Austrodromidia australis (Rathbun, 1923)

Mclay, Colin L. & Hosie, Andrew M., 2022, The sponge crabs of Western Australia and the Northwest Shelf with descriptions of new genera and species (Crustacea: Brachyura: Dromiidae), Zootaxa 5129 (3), pp. 301-355 : 307-309

Austrodromidia australis (Rathbun, 1923)

( Fig. 2A–E )

Dromidia australis Rathbun, 1923: 147 , pl. 39 figs. 1–3, pl. 40 fig. 1.— Hale, 1927: 106, fig. 101.— Griffin, 1972: 52.

Austrodromidia australis . — McLay, 1993: 18.— Davie, 2002: 158.— Poore, 2004: 303, fig. 86a.— Guinot & Tavares, 2003: 50, fig. 1c.

Type material. Holotype: AM P6200 , ovigerous female, 29.0 × 27.3 mm, 96–128 km W from Eucla, Great Australian Bight, 146–223 m.

Other material Examined. Western Australia: WAM C25772, Dampier Archipelago, collected on SCUBA by Clay Bryce, Woodside Dampier Expedition III, 1999, 20°21’00”S, 116°52’00”E: female 11.1 × 11.9 mm (large asymmetric sponge cap) ; WAM C38324, Ningaloo Project, Exmouth Gulf, 22°S, 114.25°E, 1-10-1974, 18 m: female 12.3 × 12.8 mm .

Description. Carapace approximately as wide as long, sub-pentagonal in outline, gently convex, covered in soft coarse tomentum; rostrum prominent, lateral teeth blunt, triangular, much longer than median tooth sited at a lower level, scarcely visible dorsally; margin strongly concave on each side of strong sub-acute supraorbital tooth, postorbital tooth blunt prominent, strong suborbital tooth partially obscured by supraorbital tooth in dorsal view. Small blunt subhepatic tooth partially visible dorsally. Anterolateral carapace margin armed with 3 evenly spaced teeth, first much larger, blunt, directed anterolaterally, second and third subacute marking widest point. Posterolateral tooth small behind weak branchial groove. Posterolateral carapace margins convergent to gently convex posterior margin. Sub-hepatic area sloping towards buccal area, 1 tooth beneath first anterolateral tooth and smaller tubercle near corner of buccal frame.

Chelipeds nodular; fingers gaping, occlusal teeth white; outer face of carpus armed with 2 small proximal tubercles and a triangle of 3 strong blunt tubercles inferior pair strongest, superior margin armed with small tubercle mid-way and inner distal margin armed with another at upper corner.

P2 and P3 carpus and propodus with strong distal lobes, dactylus inner margin with 3 small spines. P4 much shorter, strong curved dactyl opposed by single propodal spine. P5 sub-dorsal, flattened, reaching second anterolateral tooth, strong curved dactyl opposed by 2 equal propodal spines with another 2 unequal spines on outer propodal margin. Crista dentata on third maxillipeds consist of 9 or 10 small acute teeth.

Abdomen of female with uropods well developed, visible externally, telson margin strongly convex. Female sternal grooves ending close together on transverse ridge just behind chelipeds.

Remarks. Distinctive features of A. australis are a strong projecting rostrum; strong supraorbital, postorbital and suborbital teeth (in A. insignis the postorbital corner is bluntly rounded); the anterolateral margin is armed with several strong teeth tending to decrease in size posteriorly (2 small blunt teeth evenly spaced in A. insignis ).

Distribution. Southern Australia: New South Wales, South Australia, Tasmania, Victoria and Western Australia. Depth 10– 220 m.

Figures

FIGURE 2. Austrodromidia australis (Rathbun, 1923), female carrying sponge, 11.1 × 11.9 mm (WAM C25772): A, dorsal view; B, dorsal view close up right anterolateral carapace margin; C, E, frontal view; D, frontal view right anterolateral carapace margin and cheliped.