Re: Rediscovery of Kelaart's Thuridilla coerulea from Andaman and Nicobar Islands

Dear Vishal,

These photos are particularly interesting because they suggest to me that T. moebii and T. undula are just extreme colour forms of the much older T. coerulea.

Sreeraj's message [#23355] shows a rather typical specimen of T. moebii, with a white-spotted brownish orange border to the parapodia. I have already discussed [message #23404] the similarities between T. coerulea, and T. undula.

Your photos here show what looks to me to be an intermediate between T. coerulea and T. moebii. The biggest problem with all these names is that we have so few records of these species that we have little knowledge of colour variability. Your messages, and Sreeraj's, from the Andaman & Nicobar Islands suggests you may be sampling a population of one species with a variable colour pattern. If this proves to be true, the oldest name would be T. coerulea.

As I discuss on the T. coerulea Fact Sheet, another similarly coloured species, T. lineolata, differs in having an orange band along the base of each parapodia.

In the close-up I have ringed the everted penis.

Best wishes,
Bill Rudman