Thuridilla multimarginata
Gosliner, 1995

Superfamily: ELYSIOIDEA
Family: Elysiidae


Indo-West Pacific


Lizard Island, Queensland, Australia. 7 January 2004, at 8m depths on coral. Body length about 8mm. Photo: Nils Anthes

The animal is essentially orange with white colour markings on the head and a undulating multicoloured submarginal band on the parapodia. There is some blackish shading along the anterior end of the head and at the rhinophore tips. There is an opaque white band running forward on the head between the eyes. It splits in two anteriorly, an arm running up the dorsal surface of each rhinophore. In some animals this white Y is outlined in black. The edge of the parapodia is thrown into sinuous folds and has a conspicuous and characteristic series of colour bands. Right at the parapodial edge is an opaque white band which enlarges into a swelling [perhaps glandular?] at regular intervals along the parapodial margin. Inside this is a thin orange line which follows a wavy course as it runs around each white swelling. The other colour bands follow this same wavy course. Alongside the orange band is a band of black, then blue, then black. Gosliner describes the animals as being 'light to dark green' but the few photos I have seen show the parapodia and other parts of the body as orange. I can only presume that in recently fed animals, the body and parapodia below the colour bands, is green.

• Gosliner, T. M. (1987) Nudibranchs of southern Africa, a guide to opisthobranch molluscs of southern Africa. 136 pp. Sea Challengers.
• Gosliner, T.M. (1995) The genus Thuridilla (Opisthobranchia: Elysiidae) from the tropical Indo-Pacific, with a revision of the phylogeny and systematics of the Elysiidae. Proceedings of the California Academy of Sciences, 49(1): 1-54.
• Marshall, J.G. & Willan, R.C., (1999) Nudibranchs of Heron Island, Great Barrier Reef.

Authorship details
Rudman, W.B., 2004 (January 11) Thuridilla multimarginata Gosliner, 1995. [In] Sea Slug Forum. Australian Museum, Sydney. Available from