Spotted from of Chromodoris striatella

Dear Valda,
This is an interesting find. I have an answer to its identity, which I was going to keep 'unpublished' until I had some irrefutable photos to show an intermediate stage between this colour form and Chromodoris striatella. I did in fact find some juveniles in Koumac, New Caledonia, in 1993, but of the 40 rolls of film I exposed there, the only photos I had were on 3 rolls which were ruined by some disaster with the flash. I have posted some photos of the spotted form from New Caledonia, above.

However with your photo, and Angel Valdes' posting on Chromodoris mandapamensis, it seems a bit silly not to draw everyone's attention to the real possibility that C. striatella has a spotted colour form. Valdes, Mollo & Ortea (1999) mention the similarity in colour pattern between C. striatella and C. mandapamensis but say the latter is clearly distinguished by the spots. From my observations I don't think the spots are a clear distinction at all.

It would be nice to discover what sort of egg ribbon the spotted form produces. C. striatella is one of the few chromodorids in which the egg ribbon is layed flat on the substrate, like a sacoglossan, rather than attached along the edge of the ribbon. Other points of interest would be to see what sponge it feeds on, whether it associates with lined C. striatella, and best of all whether it mates with lined C. striatella - Just a few little things to look out for on your next dive.

Best wishes,
Bill Rudman.