February 12, 2000
From: Don Barclay
A few nights ago (31 Jan 2000) I went back to the location where I had found the little red bubble shell to see if I could find another one. The moon was dark and the tide low, and lots of different molluscs were stirring, but nothing that looked like a Bullina. I found several Mitra species that are uncommon in Samoa, plus this little nudibranch. It isn't pictured in either of the books that I have, and I've been through most of the possibilites on your site without finding it. If it is something so common that it's not worth listing, please just trash this post. Otherwise, I would be interested in the ID. This is one that I haven't seen before, and it came from the west side of Pago Pago Harbor, Utulei village, in about two meters of water where it was crawling up the side of a boulder encrusted with Halimeda patches and scattered coral growths. When it is stretched out crawling, it measures approximately 25mm. As the photos mostly show, it is nearly transparent, cream colored with small orange dots, and the sides of the foot are tinted pale green.
firstname.lastname@example.orgBarclay, D., 2000 (Feb 12) Gymnodoris citrina from Samoa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/1867
Your nudibranch is Gymnodoris citrina. It is one of a family of hunting nudibranchs which feed on other sea slugs, each species having a fairly particular group of species that they prefer to eat. One reason I haven't many species displayed on the Forum is that I am in the process of preparing a scientific revision of the genus, and I thought it would be easier to wait until I have the story straight. Gymnodoris citrina is found throughout the tropical Indo-West Pacific and is often found on sandy grass-beds as you describe for your animal.
I'm glad to hear you are out hunting for Bullina.