Austraeolis catina from St Kitts, Caribbean Sea

Dear Eric,

Thanks for the excellent photos which shows the shape of the rhinophores very well. As I mentioned in an earlier message [#19814], in almost all the photos I have seen of this species it is on the same species of sponge. If it belonged to a family of nudibranchs that ate sponges I would be pretty convinced we had found its choice of food. However, with few exceptions, species of aeolids feed on cnidarians, including sea anemones and hydroids. I would expect this species to feed on one or more species of hydroids, and in your photo there is a network running over the sponge colony - it looks whitish, because whitish particles seem to have become stuck to whatever is forming the network. In the close-up alongside, I am pretty sure I can see the skeletons of small stalked hydroids which may well be this species' food.

Best wishes,
Bill Rudman