Stimdromia lamellata ( Ortmann, 1894 )

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 : 346

Stimdromia lamellata ( Ortmann, 1894)

( Fig. 31A–C )

Cryptodromia lamellata Ortmann, 1894: 34 , pl. 2, fig 8. — Ihle, 1913: 34.

Petalomera lamellata . —Rathbun, 1923: 154, pl. 42 fig. 2–3.— Guiler, 1952: 37.— Griffin, 1972: 55, figs. 1f–j.

Stimdromia lamellata . — McLay, 1993: 168–169.— Poore, 2004: 307, fig. 87b.

Material examined. WAM C13557, Point Peron , coll. W. H. Butler , 28-04-1962: female 13.5 × 12.0 mm (sponge cap) (right gill chamber swollen by bopyrid parasite); WAM C53545, off Koolama Bay, 13°49’44”S 127°15’46”E, coll. A.M. Hosie & A. Hara , CSIRO King George River Expedition, 12-06-2013: male 15.5 × 14.0 mm ; WAM C53546, Off Koolama Bay, 13°47’23”S 127°16’37”E, coll. A.M. Hosie & A. Hara , CSIRO King George River Expedition, 12-06-2013: male 14.5 × 12.6 mm .

Description. Carapace slightly wider than long, surface gently convex, mostly devoid of setae, finely granulated (especially in frontal area); cardiac and branchial grooves faintly marked. Rostrum tridentate, teeth bluntly triangular, similar in length, median tooth on lower level, lateral teeth separated by broad sulcus extending posteriorly as shallow frontal groove; supraorbital margin interrupted by small tooth, post-orbital corner with small projection, suborbital margin armed with small tooth not visible dorsally. Anterolateral margin initially concave followed by largest tooth and 3 smaller teeth along convex margin interrupted by faint branchial notch (more evident on right hand side. In the present specimen there are some differences between the right and left-hand sides of the carapace. Sub-hepatic area finely granulate with 2 teeth, second larger tooth visible dorsally below margin of post-orbital concavity.

Cheliped merus inner face smooth, flattened; carpus flattened armed with 3 prominent unequal tubercles on outer face; propodus superior face bearing 3 smaller tubercles, outer face with several small granules some arranged in rows; fingers white, down curved, not gaping widely, margins armed with 8 or 9 small interlocking occlusal teeth. P2–3 shorter than cheliped; flattened, ridged, tuberculate, especially on distal ends of articles; dactylus short, curved, inner margin armed with 2 strong spines. Merus and propodus of P1 and P2 with entire dorsal crests. P3–4 reduced, used to carry camouflage cap, P4 shortest, P5 flattened sub-dorsal, dactylus opposed by single, long, propodal spine.

Abdomen fringed with short dense setae. Telson of mature female much wider than long, posterior margin strongly truncated; uropods visible externally. Abdominal surface strongly ridged along axis, with concave sulcus on each side; lateral margins of segments 3–5 each with small blunt tubercle. Female thoracic sternal grooves deeply marked, converging but ending apart on low swellings between bases of P2.

Remarks. Distinctive features of S. lamellata are the finely granulated carapace with granules extending on to the subhepatic area and third maxillipeds, anterolateral margin shoulder-like armed with unequal teeth, merus and propodus of chelipeds and walking legs flattened with dorsal crests or lamellae, telson posterior margin truncate (see also Griffin 1972).

Distribution. The type locality is Thursday Island, Torres Strait, Queensland and the species is known from Queensland, New South Wales, Victoria, Tasmania and Western Australia; depth range 10– 120 m.

Figures

FIGURE 31. Stimdromia lamellata (Ortmann, 1894), female, 13.5 × 12.0 mm (WAM 116-83): A, dorsal view; B, frontal view (with sponge cap); C, ventral view (with sponge cap). (Note that the chelipeds are detached. The shape of the right hand side of carapace is distorted by a bopyrid parasite in the swollen gill chamber)