Dendrodoris nigra Stimpson, 1855

Yonow, Nathalie, 2012, Opisthobranchs from the western Indian Ocean, with descriptions of two new species and ten new records (Mollusca, Gastropoda), ZooKeys 197, pp. 1-130 : 40-41

Dendrodoris nigra Stimpson, 1855 Plates 57, 58

Dendrodoris nigra . - Edmunds 1971: 383, fig. 21 and references therein (Tanzania); Gosliner 1987: 87, fig. 144 (South Africa); Debelius and Kuiter 2007: 259 (Oman, Persian Gulf + W Pacific); Yonow 2008: 212 (Red Sea); Apte 2009: 173, fig. 3e (Laccadive Islands); Richmond 2011: 282 (East Africa).

Material.

Socotra: two pres. specimens 18 × 13 mm and 16 × 9 mm (IT-177, RJ-032; the smaller has a white submarginal band), 12°41.326'N, 54°05.175'E, 14 April 1999, leg. R Janssen. - Maldives: two specimens 16 × 4 mm and 19 × 5 mm (MDV/AB/96/6), found separately under rocks, Fulidhoo Lagoon, Felidhoo Atoll, 04 May 1996, leg. RC Anderson & SG Buttress; photo of one red individual, 1986-1994, J Hinterkircher. - Zanzibar: 30 × 15 mm pres. ("black, frilly skirt, domed dorsum, no white specks"), in coral rock, 1994, leg. MD Richmond. - Gulf of Oman: photo of three individuals, Muscat, 01-12 April 2009, S Kahlbrock. - Seychelles, one individual photographed, Lilôt, NW Mahé, 1988-1989, P Kemp. - La Réunion, Mauritius, and Mayotte: photographs of several individuals http://seaslugs.free.fr/nudibranche/a_intro.htm.

Description.

The preserved specimens of Dendrodoris nigra are all black, a little longer and thinner, and much firmer than Dendrodoris fumata , which has a thinner but more extensive mantle skirt. In the two Socotra specimens of Dendrodoris nigra , black or dark grey in preservative ten years later, the large white mantle glands are still clearly visible; additionally, in the smaller specimen, there is a substantial and distinct white submarginal band, presumably red in life. The two Maldives specimens of Dendrodoris nigra are relaxed and also retain their small white spots (examined 15 years later). The gills and rhinophores are extended and the gill clump is relatively small. The photograph of the only non-black Dendrodoris nigra from the Maldives is clearly a juvenile: it had a narrow mantle skirt and was pale translucent red with small white spots and flecks as well as a black marginal band (Plate 58). The gill clump was small (but translucent red), the tri-coloured rhinophores were translucent red basally, black distally, with a large white knob at the tip; these are characters typical of Dendrodoris nigra , reviewed by Brodie et al. (1997) based on Pacific specimens. Dendrodoris fumata is never black, nor does it have white spots or glands on the dorsum ( Brodie and Calado 2006).