Stylocheilus longicauda
(Quoy & Gaimard, 1825)

Family: Aplysiidae


Circum-tropical (Indo-West Pacific & Atlantic).


UPPER: Koumac, New Caledonia, October 1993, 15m, outside of reef, on coral slabs, 15mm long alive. Inset: showing eyespots and longitudinal lines.
LOWER: Coffs Harbour Region, northern New South Wales, intertidal, December 1990. Length: 50mm.
PHOTOS: Bill Rudman.

NOTE: This page was replaced on 5 August 1999, when the true identity of S. longicauda was determined. See discussion on the true identity of S. longicauda, S. striatus, and S. citrinus.

This relatively small elongate Sea Hare usually has dark longitudinal lines and scattered eye spots, either with pink or blue centres. Although usually smaller, animals I collected in Zanzibar (1976) grew to 6.5cm in length. Like many Sea Hares they produce a purple ink when disturbed.

Like Bursatella leachii, this species feeds on blue-green algae which form a mat or film over rocks or the surface of muddy shores. Found from the intertidal to about 30m, Stylocheilus longicauda can sometimes be found in large numbers. (See Cory Pittman's message for a description of aggregations of Stylocheilus in Hawaii.

I have listed some references on various aspects of the biology, physiology and natural history of Stylocheilus separately.

Authorship details
Rudman, W.B., 1999 (March 11) Stylocheilus longicauda (Quoy & Gaimard, 1825). [In] Sea Slug Forum. Australian Museum, Sydney. Available from