December 23, 2004
From: Eddie Hardy
I recently acquired the two shells whose images are attached here. The shells were collected in 1981 in Hermanus which is now a well-known tourist resort about 40 miles along the coast east of Cape Town. The collection is not very accurately ID'd so I would appreciate a view on these two shells. They are both about 40mm long.
Locality: Die Plaat, Hermanus, Depth: not known, South Africa. Atlantic Ocean, [Indian Ocean nominally starts 40 miles or so further east]. 1 June 1981. Photographer: Eddie Hardy.
email@example.comHardy, J.E., 2004 (Dec 23) Philine aperta from east of Cape Town. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/12808
Your shells are probably from Philine aperta. I suspect the apparent difference in shape between the two is just a result of the angle they are photographed at. Macnae (1962) reports it around much of the South African coast from at least Saldanha Bay to Inhaca in Mozambique.
Without a study of its anatomy it's difficult to be 100% sure this species is the same as the common species in Europe and the Mediterranean.There seem to be a group of species around the world with very similarly shaped shells, and similar anatomical characters, such as unequal-sized gizzard plates as described for Philine angasi. It does seem unusual for a European species to also be at home in the Indian Ocean, but it will need someone to have a good look at their anatomy before we can be sure what is going on.
Macnae, W. (1962) Tectibranch molluscs from Southern Africa. Annals of the Natal Museum, 15(16): 183 - 199.
Philine aperta from Tunisia
From: J. Ben Souissi and A. Eters, July 26, 2003
Philine aperta? from Mediterranean France
From: Erwin Koehler, December 17, 2001
Photos and observations on Philine aperta
From: Bernard Picton, January 25, 1999
From: C. Duffy, October 9, 1998