Stegopontonia commensalis Nobili, 1906

(Figure 4A)

Restricted synonymy:

Stegopontonia commensalis: Nobili, 1906: (figs. lg, 6a, 8d), Bruce, 1984: 147; Li, 1997: 38, 241–242.

Material examined. 2 individuals (1 ovigerous and 1 male) (tl 22 and 18 mm, cl 8 and 6.5 mm), Agatti Island, Lakshadweep, rocky intertidal, on Echinothrix sp. (10o50’37.63”N 72o11’19.19”E), coll. S. Prakash and M. Gopi, 26th April 2011, (MBRC /ZSI M1-55).

Diagnoses based on the collected material. Body greatly elongated; rostrum depressed, toothless, concave formed as a cover at the base of the eye and presence of antennal spine. Telson elongated with two pairs of small dorsal spines, posterior margin with three pairs of spines. First pereiopod with fingers robust and depressed, second pereiopods irregular, movable and fixed finger of the larger one with three teeth on their opposite margin respectively, dactylus of third pereiopod with protuberance and unguiculate and hook like. Uropod over reaching the telson.

Habitat. Collected under the rocks in the intertidal area with the depth range from 0.5– 1m. Frequently associated with sea urchin.

Host. Diadema setosum, D. savignyi, D. paucispinum, Echinothrix calamaris and E. diadema (Bruce, 1982) . Current specimen was associated with sea urchin, Echinothrix sp ..

Distribution. Kenya, Zanzibar and Tuamato Archipelago, Mauritius and Seychelles, New Caledonia, Great Barrier Reef and Hawaii (Bruce, 1982). Now from India.

Remarks. This is the sole species of the genus Stegopontonia and recorded for the first time from Indian waters.