Often called Butterflies of the Reef, Nudibranchs and Snails often exhibit vivid, dazzling colors.They are found in nearly all reef habitats, from shallow to very deep.It is estimated that there are over 3000 species of them, and many new ones are being discovered.
Nudibranchs are snails without shells. Both snails and nudibranchs move with a large foot. Many nudibranchs are distinguished by two rhinophores (sensory organs) and multiple gills.
The majority of Nudibranchs feed on algae, sponges, hydroids and anenomes. Most shelled snails are carnivores feeding on bivalves such as clams and oysters.
Although highly colored, these small denizens of the reef feature sophisticated protective mechanisms to ward off predators. They employ chemical secretions which are frequently toxic or distasteful. Others ingest the stinging cells of the hydroids they eat and are able to reuse these as protective devices.