Alder & Hancock, 1845
European coast of North Atlantic. Odd records from such places as the Suez Canal and New Zealand are probably either misidentifications or evidence of ship-borne distribution.
All photographs were taken in the Oosterschelde, the Netherlands, at various places in September 1999 and January 2000. UPPER RIGHT: On compound ascidian Botryllus schlosseri. LOWER LEFT: Laying egg-ribbon. LOWER RIGHT: egg-ribbon. Photos: Peter van Bragt.
The mottled brown and white colouration are usually an effective camouflage. Often found partially buried in a hollow which they excavate in the ascidian colony on which they are feeding. Normal foor ascidians are Botryllus schlosseri and Botrylloides leachi. Can grow to about 40mm long. See Peter van Bragt's message below for more photos, including one of animal on Botrylloides leachi.
• Alder, J. & Hancock, A. (1845). Notice of a new genus and several new species of nudibranchiate Mollusca. Annals & Magazine of Natural History, 16: 311-316.
Rudman, W.B., 2000 (September 17) Goniodoris castanea Alder & Hancock, 1845. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/gonicast