Goniobranchus collingwoodi (Rudman, 1987)

Yonow, Nathalie, 2018, Red Sea Opisthobranchia 5: new species and new records of chromodorids from the Red Sea (Heterobranchia, Nudibranchia, Chromodorididae), ZooKeys 770, pp. 9-42 : 18

Goniobranchus collingwoodi (Rudman, 1987) Figure 3 , Plate 6

Chromodoris collingwoodi Rudman, 1987: 358-364, figs 23E-F, 32-35 (eastern Australia, Solomon Islands, Hong Kong); Baba 1989: 23, fig. 2; Rudman and Darvell 1990: 58, pl. 6B (Hong Kong); Wells and Bryce 1993: 117, fig. 144 (western Australia); Yonow 2001: 11, pl. 1 fig. 1 (Indonesia); Hervé 2010: 233 (New Caledonia).

Material.

Rosalie Moller wreck, near Hurghada, Egyptian Red Sea, 28 Apr 2015, 40 m depth, 50-60 mm alive, 21 × 10 mm preserved leg. and photographs S Kahlbrock (SK # 3).

Description.

The photographs perfectly fit the description of this species by Rudman (1987) (Plate 6 ). The dorsum is cream with a purple margin. Inside the purple margin is a broad opaque white band containing many yellow spots on the outside and very few purple spots on the inside. There is an ochre zone linking the white band to the dorsal hump, which is covered in brown patches and purple spots, and both are overlain with white spots. The rhinophores are brown with the edges of the lamellae being white. The quadrangular gills have a more complicated colour pattern, translucent with a dark brown or grey line down the edges of the pinnules on both their outer and inner sides, the pigmentation extending onto both sides of the pinnules. Some of the gills are branched or forked, and they are numerous, arranged in a double spiral around the anal papilla. The foot extends a short distance behind the mantle and is white with many round yellow spots and a purple patch on the margin.

Ventrally, the preserved specimen is monochromatic. The margins of the mantle and foot are contracted and the anterior margin of the foot is bilaminate (Figure 3 ).

Remarks.

This is the first record of this well-known western Pacific species from the Red Sea. There are no literature records of this species from the Indian Ocean (e.g., Tibiriçá et al. 2017, SeaSlugForum, http://seaslugs.free.fr/nudibranche/a_intro.htm). It remains to be seen if this is a one-off introduction or whether the species will establish itself in the either the Red Sea and/or the western Indian Ocean.

Figures

Figure 3. Goniobranchus collingwoodi (Rudman, 1987) ventral view of anterior showing head, oral tentacles, and foot margin.

Plate 6. Goniobranchus collingwoodi (Rudman, 1987), photograph S Kahlbrock.