Philinopsis speciosa from Hawaii

Dear Scott,
I remember now that my hesitation in synonymising P. cyanea with P. speciosa in 1972 was based on the similarity of this white-spotted colour form to New Zealand specimens of Philinopsis taronga and the NE Pacific species P. gigliolii. Now I wonder if they are all temperate forms of one widespread species.

Leaving them aside, your animals from Hawaii, and Mike Roberts photo of dark form [#14082] suggest that the whole range of colour variation is found in Hawaii. Considering I could find no significant anatomical differences between Hawaiian specimens of P. speciosa and Indian Ocean specimens of P. cyanea [see Rudman, 1972] it seems there are no reasons to consider them distinct species. Some will say we should try and use the International Rules to suppress the older, but relatively unused name, Philinopsis speciosa, but as it is the type species of the genus, we can hardly call it unused.

I am not quite sure what we should do with Philinopsis depicta from the Mediterranean. I have long felt it was probably the same species as the Indo-West Pacific P. cyanea [or rather P. speciosa]. In fact the two photos on the P. depicta Fact Sheet are almost identical to the two colour forms of Philinopsis speciosa illustrated from Hawaii here in the message from Scott Johnson and in Mike Roberts's [#14082]. There also appear to be no major anatomical differences. If we accept that P. depicta also occurs in the Caribbean [see messages #9570 , #14642], perhaps we have here a single species with a circumglobal distribution, like Hydatina physis and Micromelo undata?

Best wishes,
Bill Rudman