Glossodoris dendrobranchia? from Guam

Note added 5 Feb 2007: This is most probably Glossodoris tibboeli [see message #19385]

Dear Hisako,
This is a species of Glossodoris, and it looks very like Glossodoris dendrobranchia. But in that species the gills and rhinophores are pale creamy white and in your photos they seem to be dark brown. One thing that puzzles me is that you say you find this species commonly at Guam. G. dendrobranchia is only known from a few records from the Great Barrier Reef, and I am pretty sure it has not been recorded from Guam.

Have a look at the page on Glossodoris atromarginata which is a species which can be very similar in colour to your photo but has a dark brown or black line at the edge of the mantle. It is a common species throughout the tropical Pacific and Indian Oceans and occurs in Guam.

It is of course possible that this animal with no black edge is common in Guam, but if so it is a very interesting find. If you have other photos that show the gills I would like to see them. In the meantime I am sure Clay Carlson, who has many years experience in Guam, will be able to help us out.
Best wishes,
Bill Rudman