Siraius immonda from Japan

Dear Yasuhiro,
I identify this animal as Siraius immonda Risbec. It is the same animal that has recently been identified as Siraius nucleola. Specimens from Australia (Willan & Brodie, 1993) are usually a yellow or orange colour, but Baba has reported animals from Japan which range in colour from yellow to blue green. (see References at Top of Page).

I have included [far right] a copy of Risbec's illustration (1928: Plate 1, fig 4) of a species he named Platydoris immonda from New Caledonia, which is clearly the same species. I have put a photo of an animal from New Caledonia at the Top of the Page. The name suggested by Willan & Brodie (1993) and used by Baba (1993), is based on a species described by Pease (1860) from Hawaii, Doris nucleola, the description of which was not illustrated, and makes no mention of the characteristic markings in the dorsal midline. The paintings [Fig 10, 11 on right] are Andrew Garrett's, subsequently published by Bergh (1881: Plate G), of the animal described by Pease.

I think the earliest recognisable name for this species is Platydoris immonda Risbec, 1928. I have followed earlier authors in placing it in the genus Siraius but am not sure whether an exhaustive review of the dorid genera would agree with that decision.

Best wishes,
Bill Rudman.