Melibe australis
Angas, 1864

Family: Tethydidae


Temperate Australia from Cape Naturaliste, Western Australia. to northern New South Wales, from the lower intertidal to 10 m deep.


Data: Arrawarra Rock platform, Woolgoolga, Northern New South Wales. 3 Dec 1990 At LWS. Numerous specimens (approx. 28 mm long) AM C164561. Photos: Bill Rudman

Body slender, up to 30 mm in length, soft, high, rounded with dendritic papillae covering the notum. There are usually 5 pairs of cerata. The stalked cerata have a characteristic flask-like shape, the bottom half being smooth and concave and the upper half being papillate and rising to a central apical papillae [lower left photo]. papillae restricted to the dorsal side. The cerata are easily autotomised. The oral hood is relatively small and rounded in shape. The small rhinophores have a elongate sheath. the animals showed a huge range of colour, some of which is illustrated here. Some were transparent with a few brown & white specks. Others have opaque white, pink or orange pigment on the dorsum and the flat outer surface of cerata. The oral hood similar in colour to dorsum. When resting, with the stalked cerata 'tucked in', the opaque pigmented specimens look just like ascidian colonies [see separate message]. When sitting, the oral veil is held antero-dorsally, and the front of the foot is conical, like the tail.

The species is the smallest in the genus. It produced a strong smell when handled which has been described variously as sweet and musky to strong and acrid. They are usually found either under rocks on the lower shore in areas where brown algae are the dominant algae, or on brown algae.

The photos show a typical specimen [upper right] which is translucent white with little pigmentation, and an animal with a heavy covering of opaque pink pigmentation [lower right].

• Angas, G. F. (1864) Description d'especes nouvelles appartenant a plusieurs genres de Mollusques Nudibranches des environs de Port-Jackson (Nouvelle-Galles du Sud), accompagnee de dessins faits d'apres nature. Journal de Conchyliologie, series 3, (12): 43-70, pls. 4-6.

Authorship details
Rudman, W.B., 2003 (February 26) Melibe australis Angas, 1864. [In] Sea Slug Forum. Australian Museum, Sydney. Available from

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  3. Melibe australis from Woolgoolga, northern NSW
    From: W.B.Rudman, March 1, 2003
  4. Melibe australis - ascidian mimic
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