Chromodoris aureomarginata feeding

Dear Floor,
Thanks for these interesting photos. I have been trying to get information on the feeding of this species for some years without success, and during my short visit to New Zealand I saw a tantalising video clip in the Auckland Museum of this species on a sponge, which revitalised my search. You were one of a number of New Zealand underwater photographers I contacted about this species and Ceratosoma amoena, and your message is one of a number I am posting today from the almost instantaneous response I have received from my request.

The only information I had on C. aureomarginata feeding was a note by Michael C. Miller of it feeding on 'Dysidea fragilis' (see Miller, 1967). Both the photos in your message show it feeding on a species of Dysidea. As this is an unusual sponge for a species of Chromodoris to be eating, it is a very valuable confirmation of Michael Miller's observations from 40 years ago. He also reported C. amoena to feed on Dysidea, and in your lower photo we can see that species as well. [see message #19842 for fuller photos of that species].

The middle left photo is a close-up showing the oral tube everted, which along with the damaged and decolorised sponge alongside, is pretty good evidence of feeding.

• Miller, M. C. (1967) Grazing carnivores - some sea-slugs feeding on sedentary invertebrates. Poirieria (Conchology Section Auckland Institute & Museum), 3(1): 1-11.

Best wishes,
Bill Rudman