Glossodoris cincta, (Bergh, 1888)

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 : 856-857

Glossodori s cincta (Bergh, 1888)

(®gure 13c) Glossodoris cincta (Bergh) : Rudman, 1986a: 149, numerous ®gures; Yonow, 1994a: 120, ®gure 10H.

Material. Chag96/59: 27 mm; on rubble near bommie east of Ile Poule, inside Peros Banhos Atoll; 23 February 1996; at 7 m depth. Chag96/82: 25 mm; Three Brothers, Great Chagos Bank; 3 March 1996; at 5 m depth. Chag96/92a, b: 37 mm, 35 mm; Victory Bank; 3 March 1996; at 8 m depth.

Description. The body is solid and the mantle edge undulated, with a noticeably enlarged permanent fold mid-laterally on both sides. The mantle edge appeared dark green from a distance, but comprised an outer royal blue margin and an olive green submarginal band (®gure 13c). The dorsal surface was pustular and mottled pinkish brown, speckled with white and yellow dots; there was a darker central ®eld extending from the rhinophores to the gills. The foot was dark pink, mottled with white-tipped pustules, with thin bright blue and olive green marginal bands. Rhinophores were dark brown speckled with white; white midline present anteriorly and (in one specimen) posteriorly. Gills pale brown, with ®ne dark edges.

The preserved specimens are all well relaxed; they retain the red marbling on the dorsum and the blue and green margins on the mantle and foot. The colour pattern on the gills and rhinophores also remains. All specimens have stained their formaldehyde preservative yellow to yellowish brown.

Geographic distribution. Indo-West Paci®c: Red Sea (Yonow, 1989) and western Indian Ocean (Yonow and Hayward, 1991; Yonow, 1994a) to Christmas Island (Indian Ocean), north Australia and the Philippines (Rudman, 1986a).

Remarks. This species is well known, occurring in several colour morphs: these specimens conform with the Red Sea and western Indian Ocean form which has a mottled red dorsum, an olive green submarginal and thin blue marginal line. In life the gills vibrated constantly in specimen 96/59, a feature also noted for the specimens from East Africa and the Philippines (Rudman, 1986a), and typical of numerous species of Glossodoris . Specimen 96/92 was photographed in situ on a black sponge (cf. specimen from Maldives on purple sponge in Yonow, 1994a: ®gure 10H).