Risbecia godeffroyana feeding & trailing [1]

Dear Bruce,
Thanks very much. Another very valuable contribution. In the upper right photo we have the usual tantalising situation where it seems to be feeding but I am not sure on what. I am pretty sure it is not the bright orange-red sponge but most probably the whitish translucent patch just below the head. However in the middle left photo there are two animals which seem to have excavated a huge feeding hole. All we can see of the upper animal is its gills. I am pretty sure what they are eating is the greyish sponge - a species of Euryspongia - which you can see in the close-up on the right. It seems the Euryspongia colony is partly overgrown by the yellow sponge at the bottom and the reddish sponges on either side of the hole. I haven't posted your whole photo but in it I can see more patches of the greyish sponge further away. The way these sponges compete for space by overgrowing each other certainly makes identifying nudibranch food sources very difficult. It also make sampling colonies difficult because it is often impossible to get a sample of one species without contamination from other nearby species

These trailing photos certainly give the impression, as Roberto Sozzani suggested [message #17592 ] that these animals can't bear to be apart.

Best wishes,
Bill Rudman