Food preferences of British nudibranchs.


Dorid nudibranchs all have a rosette of branched gills surrounding the anus in the posterior region of their backs. True dorids such as Archidoris have broad radulae with typically 20-60 teeth per row and feed on sponges. Phanerobranch dorids such as Polycera and Onchidoris have narrow radulae typically with two principal teeth and usually a series of smaller hooks or plates. They feed on Bryozoans or Tunicates and a few have odd diets such as Onchidoris bilamellata which eats barnacles.


The arminaceans are a rather motley assortment of nudibranchs which do not fit into the larger suborders. They have either lateral gills like dendronotaceans (eg. Hero), gills in a slit between the mantle edge and foot (eg. Armina) or cerata like those of aeolids, but without cnidosacs (eg. Janolus). They feed on a variety of diets, especially Cnidarians and Bryozoans.


Dendronotacean nudibranchs are elongate molluscs with lateral gills, usually in pairs, arising from the pallial rim. They usually have sheaths around the rhinophores. Most species feed on soft corals, anemones or hydroids.


Aeolid nudibranchs are elongate agile molluscs with numerous cerata on their backs. Most feed on various hydroids, with a smaller number in the family Aeolidiidae feeding on sea anemones and a few such as the egg-eating Favorinus spp. and Calma with more unusual diets. They are the main suborder in which the stinging cells from their Cnidarian (Coelenterate) diet are transferred through the digestive gland in the cerata to the terminal cnidosacs, for use in defence of the nudibranch.