Thorunna daniellae from Midway

Note added 4 October 2003: This is Thorunna kahuna. See message.

Dear Keoki,
Thanks for this great photo. I have included an enlargement of the posterior and anterior ends of the animals because they clearly show white mantle glands. Such glands are found in most chromodorids, and each genus has a quite distinctive arrangement of the glands. Over the years I have examined specimens of most species of Thorunna and have had very little success in finding any distinctive evidence of these glands in the genus, so your photo is an important bit of information. In a review of the family some years ago (Rudman, 1984) I suggested, that based on many anatomical features, Thorunna belonged to a distinct branch of the chromodorids, which included amongst others, such genera as Hypselodoris, Mexichromis, Ceratosoma, all of which have a concentration of large mantle glands posteriorly. I suggested that if Thorunna really didn't have mantle glands then they had been secondarily lost. Your photo certainly supports my hypothesis that Thorunna belongs to the Hypselodoris 'branch' of the family with prominent posterior glands.

Could you confirm I have the date correct. I try to convert dates so they are understood worldwide. I assume your '4/10/00' is American for 10 April 2000. In my part of the world '4/10/00' means 4 October 2000.

• Rudman, W.B. (1984) The Chromodorididae (Opisthobranchia: Mollusca) of the Indo-West Pacific: a review of the genera. Zoological Journal of the Linnean Society, 81: 115-273.

Best wishes
Bill Rudman