Critter of the Week: the brightly coloured and aptly named clown nudibranch, Ceratosoma amoenum.
This week’s critter, found from the northern part of New Zealand to southern Australia, is the brightly coloured and aptly named clown nudibranch, Ceratosoma amoenum. It is in one of the largest nudibranch families Chromodorididae. Nudibranchs (http://en.wikipedia.org/wiki/Nudibranch) are shell-less marine molluscs, their name means ‘naked gills’, and this group has some brightly coloured and beautiful animals. There are some absolute stunners on this national geographic website to give you a taster: http://ngm.nationalgeographic.com/2008/06/nudibranchs/doubilet-photography
Ceratosoma amoenum is often found living on sponges, on which they feed. It can sequester toxic metabolites from the sponges as a defensive mechanism against predation by concentrating the chemicals in their mantle glands making themselves distasteful to predators. Groups of feeding or copulating clown nudibranchs can easily be spotted and are often photographed by divers as they are found from the low intertidal to about 40m.