North Island, New Zealand. Photos: Cynthia Trowbridge.
Common in upper midlittoral pools on rocky shores, this small black sacoglossan feeds on the filamentous green alga Chaetomorpha aerea. The alga is often covered in oxygen bubbles it has produced in the often warm, hyposaline water. E. felina feeds on the liquid contents of the large swollen cells easily seen in the accompanying photos. It grows to about 8mm and is black except for a paler coloured foot and a translucent white band running forward from each eye.
• Trowbridge, C.D. (1994) Life at the edge: population dynamics and salinity tolerance of a high intertidal, pool-dwelling ascoglossan opisthobranch on New Zealand rocky shores. J. Exp. Mar. Biol. Ecol., 182: 65-84.
• Trowbridge, C.D. (1995) Hypodermic insemination, oviposition, and embryonic development of a pool-dwelling ascoglossan (= sacoglossan) opisthobranch: Ercolania felina (Hutton, 1882) on New Zealand shores. The Veliger, 38: 203-211.
Rudman, W.B., 2000 (July 3) Ercolania felina (Hutton, 1882). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/ercofeli