Partly yellow Phyllidiopsis striata? from Thailand

Dear Narongpon,
This is another interesting find. Can ypou please give me some imformation on where it was photographed.

It certainly has similarities to Phyllidiopsis striata, particularly in having three longitudinal ridges on the mantle. If you look at the photos from Erwin Koehler of animals from the Maldives you will see black spots around the mantle edge like in your specimen.

However, we can't ignore the bright yellow region in the midline of your animal and the absence of the two inner black lines of P. striata. Another species or colour form from the Maldives which I am tentatively calling it Phyllidia sp. 1, may be related. It is yellow with black longitudinal lines.

A comment I made about that species: "If it wasn't bright yellow I would say that it was one of the striped species of Phyllidiopsis such as P. striata or P. phiphiensis" may in fact be so. One possibility is that juveniles are yellow and the grow blue as they age. That doesn't explain the lack of black lines in this animal from Thailand.

Have you any idea of its size please? It would be nice to know if you find any colour variations.

Best wishes,
Bill Rudman.