Okenia elegans
(Leuckart, 1828)

Order: NUDIBRANCHIA
Suborder: DORIDINA
Superfamily: ANADORIDOIDEA
Family: Goniodorididae

DISTRIBUTION

Known from the western Mediterranean and the Bay of Biscay, although there are a few records from the southern North Sea. According to Thompson & Brown (1984) most British records are from the southwest coast of England.

PHOTO

St. Kilda, Outer Hebrides, in Scotland, June 1993, Photo: Daniel Geiger, [see message below.]

A relatively large species of Okenia with a relatively high profile and a mantle edge lened with papillae of varying sizes. Around the head there are up to eight quite long papillae, the anterior pair being eaqual in length to the rhinophores. Down the side of the body there are eight to ten short papillae on each side, quite crowded together, and a similar number form a border around the gills. There are also a few short papillae spaced irregularly in the dorsal midline between the gills and the rhinophores. The rhinophores are quite long and there are about twenty gills.

This species is quite spectaculalry coloured. The background colour of the body is usually a translucent white but it can be suffused with pink and in rare cases almost red in colour. The lateral papillae range in colour in different animals and different parts of the same animal from all yellow, to yellow tips and nases with a red or orange midregion, and sometimes with a white tip. The rhinophores are with a red ot pinkish band just below the tip. The gills are translucent white with varying degrees of pinkish or red colouration. There is a yellow or orange band around the edge of the foot.

This species is reported by various authors to feed on ascidians such as Molgula, Ciona, Dendrodoa grossularia and Polycarpa rustica, i nto which it burrows, and remains concealed, during much of its life. Can grow to 8 cm long.

• Leuckart, F.S. (1828). Breves Anim. p.15, unnumbered plate, figs 2a-b.
• Picton, B. E. & Morrow, C.C., 1994. A Field Guide to the Nudibranchs of the British Isles. London: Immel Publishing Ltd.
• Thompson, T. E. & Brown, G. H., 1976. British Opisthobranch Molluscs. Synopses of the British Fauna (New Series)  The Linnean Society of London. London: Academic Press. [Synopses of the British Fauna, no. 8.]
  

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