Rostanga from South Australia
January 25, 2000
From: Stuart Hutchison
Dear Bill,
Here is another one from Edithburgh, Yorke Peninsula, South Australia, Christmas last year - about 50mm long. May be a dying Doriopsilla carneola perhaps (common at Edithburgh) but the rhinophores are dark tipped. Only sighting in five years. Regards,
Stuart Hutchison.
hutchco@tpg.com.au
Hutchison, S., 2000 (Jan 25) Rostanga from South Australia. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/1758Dear Stuart,
This is a species of Rostanga. There are a number of species found in Australian waters and all of them are very well camouflaged, looking almost identical to the sponges on which they feed. Unfortunately they are very difficult to identify without dissecting them, although I have found that each species has a very distinctively shaped egg ribbon.
I'm afraid I can't identify your species with any certainty just from the photo. If you find any more it would be useful to look around for egg ribbons on the sponge they live and feed on, or collect a specimen or two. Usually they don't move off, or far, from their food sponge, althought the common Sydney species, Rostanga arbutus is an exception, often found in intertidal pools crawling over algae.
Best wishes,
Bill Rudman.
Reference:
Rudman, W.B. & Avern, G. (1989) The genus Rostanga (Nudibranchia: Dorididae) in the Indo-West Pacific. Zoological Journal of the Linnean Society 96(3): 281-338.