NUDIBRANCHS

Nudibranchs, which means bare gills, are members of the phylum mollusca. The Mollusc phylum includes a number of seemingly very different classes; there are the Cephalopods which contain the squids, octopuses etc.; there are the Bivalves which include shells with two halves such as scallops, clams, oysters; and there are the Gastropods or stomach footed molluscs such as the snails, winkles, tritons, limpets and sea slugs. The term 'sea slugs' does very little justice to the stunningly beautiful creatures that make up the Nudibranchs

Nudibranchs have no shell, are symmetrical, and typically have gills or a pair of gills towards their rear end. The gills are often flowerlike and are retracted when the animal is disturbed. At the head end there is a pair of rhinophores. These tentacles are taste or ‘smell’ sensors and are used to help find food. Many of the species are brightly coloured, sometimes to match their favoured food but also often as a warning to predators that they are at least nasty tasting and often toxic.

Some Nudibranchs have the ability to take the poisons and stinging cells in their food and ‘send’ them to their own skin in order to give protection from predators.

Nudibranchs often have tiny commensal shrimps or even fish living on them.