Cadlinella ornatissima (Risbec, 1928)

Yonow, Nathalie, Anderson, R. Charles & Buttress, Susan G., 2002, Opisthobranch molluscs from the Chagos Archipelago, Central Indian Ocean, Journal of Natural History 36 (7), pp. 831-882 : 850-851

Cadlinella ornatissima (Risbec, 1928)

(®gure 11c)

Cadlina ornatissima Risbec, 1928: 163 : ®gure 47, pl. 8, ®gure 4.

Cadlinella ornatissima: Baba, 1949: 147 , pl. 22, ®gure 80; Risbec, 1953: 90, ®gures 45, 48, 49; Rudman, 1984: 246, ®gures 1H, 8, 95±97.

Material. Chag96/9: 14 mm; in cave on inner reef of Nelson Island, Great Chagos Bank; 3 March 1996; at 20 m depth.

Description. A brightly coloured species with a deep yellow mantle covered with many pink-tipped, near-spherical tubercles; smaller and more numerous white ones were concentrated around the mantle margin. Rhinophores white and very long. Gills white.

Geographic distribution. Indo-West Paci®c: recorded only from Tanzania (Rudman, 1984) in the Indian Ocean and otherwise from New Caledonia (Risbec, 1928, 1953), Japan ( Baba, 1949) and the Great Barrier Reef (Rudman, 1984).

Remarks. This species is rarely recorded in the scienti®c literature. It is easily recognized by its combination of bright orange mantle, pink-tipped rounded tubercles and extremely long white rhinophores. Until recently there has been only one named species of Cadlinella , but two species have recently been described from New Caledonia (Rudman, 1995) and Japan ( Baba, 1996). A further two undescribed species have been photographed in the Red Sea ( Debelius, 1996 as C. ornatissima ) and Norfolk Island (South Paci®c: Coleman, 1989: 44 as C. ornatissima ). These diOEer signi®cantly in external morphology and colour pattern from C. ornatissima , which is very constant, and from C. hirsuta Rudman, 1995 and C. subornatissima Baba, 1996 . Cadlinella hirsuta is yellow with very long, tapering, white papillae; C. subornatissima is yellow centrally and white marginally with conical papillae. The Red Sea species is white with yellow reticulations and a narrow bright yellow margin, and the fusiform or digitiform tubercles are red to pink-red for their distal half. The South Paci®c species is bright yellow like C. ornatissima but has tapering tubercles rather than round-ended cylindrical or spherical ones, suOEused with very pale pink. Perhaps more signi®cantly, the rhinophores are bright yellow.

(a) (b)

(c) (d)

(e) (f)