Actinopyga obesa

Actinopyga obesa (Selenka, 1867) Figure 3 Mülleria obesa Selenka, 1867:312. Actinopyga obesa Fisher, 1907: 647, pl 67, fig. 8; Cherbonnier, 1988: 20, fig.3; Rowe & Gates, 1995:287. Thandar & Samyn, 2004: 255; Samyn & Tallon, 2005 (supplementary material). Holothuria (Actinopyga) obesa Panning, 1929: 129, fig.13. Diagnosis (summarised from Selenka, 1867; Fisher, 1907; Cherbonnier, 1988) Robust, chocolate brown species, often exceeding 200 mm in length. Tentacles 20, broadly peltate. Tube feet crowded, more numerous ventrally. Anal teeth white, strong. Cuvierian tubules present, minute. Dorsal and ventral body wall ossicles similar, exclusively slightly curved, sometimes X-shaped rods, but no rosette-like bodies; rods finely spinulated/granulated, sometimes branched and perforated terminally; up to 120 µm long but usually around 80 µ. Material examined. Bassas Island (French protect.), about 350 km east coast of Mozambique, collected by the Oceanogaphic Research Institute, Durban, 06 July 1991; Sodwana Bay, Kwazulu-Natal, South Africa, collected by Samyn et al, January 2006. Habitat. Coral, up to 20 m. Distribution. Tropical Indo-West Pacific, up to 20 m. Remarks. This is the second record of this characteristic Indo-West Pacific species from the western part of the Indian Ocean. It satisfies the diagnosis of the species given above. The species is well characterized by its spinulated or finely granulated, slightly curved rods which may or may not be terminally perforated but sometimes Y-shaped. The illustration below (Figure 3) is based on the specimen from Bassas Island, just south of the tropic of Capricorn, off the east coast of southern Mozambique. More recent material originates from Sodwana Bay, on the east coast of South Africa, collected by Dr Yves Samyn and his team on their South African expedition. This specimen measures about 235 mm in length and about 30 mm in width in mid-body. Its colouration is also a very dark chocolate brown, almost similar to that of the Bassas specimen. The body wall ossicles are identical to the Bassas material.