Indopinnixa moosai Rahayu & Ng, 2010, n. sp.

Indopinnixa moosai n. sp.

(Figs. 4–6)

Material. Holotype: male (5.10 × 2.70 mm) (MZB Cru 2662), apparently free living in sand substrate with shell and coral debris, intertidal area, Sira, West Lombok, Indonesia, coll. 21 July 2009. Paratypes: 2 males (3.60 × 1.85 mm; 4.10 × 2.15 mm) (MZB Cru 2663), 3 males (4.00 × 2.00 mm; 3.30 × 1.75 mm; 4.50 × 2.25 mm) (ZRC 2010.0098); 2 ovigerous females (5.00 × 2.50 mm; 4.20 × 2.30 mm) (MZB Cru 2664); 2 ovigerous females (5.50 × 2.70 mm; 3.75× 1.92 mm) (ZRC 2010.0099), 2 females (4.30 × 2.30 mm; 4.80 × 2.40 mm) (MZB Cru 2665), 2 female (4.30 × 2.15 mm; 3.50 × 1.75 mm) (ZRC 2010.0100), same locality as holotype.

Description. Carapace (Figs. 4 A, B, 5A) 1.89 times broader than long (1.83–2.00 times as long as broad for paratypes), frontal margin slightly sinuous, about 0.17 times carapace width. Antero-, posterolateral margins separated by protuberance directed outwards. Anterolateral margin defined by crest of small tubercles starting at base of P3, ending just at swollen hepatic lobe adjacent to orbit; posterolateral margin smooth; posterior carapace margin straight. Dorsal surface of carapace convex anteriorly, posteriorly; smooth, faint indication of gastrocardiac region, short transverse ridge on hepatic region. Orbit smooth, entire, row of low granules at inner edge; ocular peduncles short, stout, corneas small, distinctly pigmented. Antennae long, flagellum in orbital hiatus. Epistome narrow. Third maxilliped (Fig. 6 G, H) with blade–like dactylus, propodus spatulate, prominently produced laterally, carpus, merus relatively narrow; dactylus, propodus, merus with very long setae. Exopod with sharp protuberance midlength of outer margin; flagellum 2- segmented, with long setae on tip (Fig. 6 G).

Chelipeds subequal, right larger (Fig. 5 B); fingers relatively slender, tips of fingers crossing when closed, narrow hiatus between fingers obscured by plumose setae; outer face of dactylus smooth, upper margin with row of tubercles, long plumose setae, cutting edge with large teeth proximally, smaller teeth distally; fixed finger with median longitudinal ridge covered by long setae; cutting edge with several moderately small teeth; upper margin, upper outer surface of palm with rows of small tubercles obscured by long plumose setae; outer surface of palm with distinct low longitudinal median ridge, obscured by long plumose setae; lower margin of fixed finger, palm with row of tubercles, inner surface near lower margin with longitudinal rows of plumose setae; carpus covered with plumose setae, outer upper margin with rows of tubercles; upper margin, inner lower margin of merus with row of small tubercles, long plumose setae.

P2, P3 (Fig. 5 C, D) of similar form, slender, shorter than P4; dactylus longer than propodus, merus long, about 3.5–4.2 times as long as broad, dorsal, ventral margins of all articles lined with short setae; P4 broad (Fig. 5 E), dactylus slightly shorter than propodus, dorsal margin with row of tubercles; dorsal margins of propodus with rows of tubercles, laterodorsal face with rows of tubercles, ventral margin bicarinate; carpus with row of tubercles on dorsal margin, laterodorsal with scattered tubercles; merus broad, 1.9 times as long as broad, dorsal, ventral margins with row of pointed tubercles; P5 shortest (Fig. 5 F), row of tubercles on dorsal margin of propodus, carpus, on ventral margin of merus; all articles of P4, P5 with long plumose setae.

Male abdomen (Fig. 6 E) relatively broad, telson broader than sixth somite, distal margin sinuous; sixth, fifth somites fused but with visible shallow suture; fourth somite narrowest, lateral margin gently convex; third somite broad, margins sinuous, first, second somites short. Female abdomen broad (Fig. 6 F), with 6 free somites, telson, without constriction. G1 stout (Fig. 6 A–D), straight, apical process thick with tip of distal part rounded; G2 short.

Etymology. The species is named after renowned Indonesian carcinologist M. Kasim Moosa, a contemporary of Kasijan, and an expert on stomatopod and portunid systematics.

Habitat. Indopinnixa moosai n. sp. was collected intertidally on coarse sand and coral rubble. The area was a damaged coral flat with many deep tide pools caused by coral mining, which was prohibited a year earlier so the area has started to recover. The crabs were obtained by sieving the sand and coral rubble from the tide pools, and were not associated with an annelid, sipunculid or any other invertebrate, although they could have been dislodged from hosts during the collection process.