Re: Chromodoris michaeli? from the Philippines

Dear Erwin,
It certainly looks like the animal you sent earlier which I identified as Chromodoris dianae. The one major difference, as I said then, was the colour of the gills. In your earlier photo the gills were translucent colorless, or whitish, with an orange mark on the outer edge, which is characteristic of one of the colour forms of C. dianae. Georg Heinze's photo however shows an animal in which the gills are a uniform translucent orange, which is characteristic of C. michaeli. However in Gosliner & Behren's original description of this species they say that the orange band around the mantle edge is 'uninterrupted'. In this animal the band around the anterior end is 'uninterrupted' but that is certainly not the case around the rest of the mantle edge.

These groups of similarly coloured species of chromodorids are often difficult to separate from one another. If we are correct in thinking that these colour groups are the result of mimicry then it is not surprising that different species look so alike.
Best wishes,
Bill Rudman