Discodorididae is one of the largest families of dorid nudibranchs (superfamily Doridoidea), with roughly thirty genera such as Discodoris, Jorunna, Peltodoris, Platydoris, Rostanga, Sclerodoris and Thordisa. They occur in all oceans from the intertidal to deep water, and several species are found in the Mediterranean. All feed on sponges, often matching their prey in colour and texture. Many are nocturnal and spend the day hidden under rocks.
◎Identification
Typical 'cryptobranch' dorids: oval, often flattened bodies with a broad mantle that is usually rough with tubercles, papillae or caryophyllidia (tiny spiculed bumps), giving a velvety or gritty look. A circlet of gills on the rear of the back and the rhinophores can both be pulled into pockets. Colours tend to be cryptic browns, greys, yellows or oranges, unlike the smooth, brightly patterned Chromodorididae.