Phyllidiidae Family

Family Phyllidiidae

The phyllidiids are a very distinctive looking family of nudibranchs the most noticeable being the lack of dorsal gills. They have an elongate-ovate shape that is evenly convex in profile. The mantle skirt is the same width as the foot, but still covers it and the reduced head completely. The mantle is stiff and tough since it contains spicules (as does the foot and body wall) and bears stiff tubercles that may be variously coloured. The colour, shape and arrangement of these tubercles are significant features in the identification of species. Glands that release acrid and toxic chemicals for defensive purposes are located in the mantle. The oral tentacles may be fused or unfused. Phyllidiids have a small mouth, with jaw plates and radula absent making them suctorial feeders. The rhinophores are lamellate and can retract into pockets. Gills are not borne upon the dorsum, instead they are simple secondary leaflets located underneath, down each side in the cavity between the mantle and foot (the hyponotum). The anus is located on the midline of the dorsum posteriorly except for some species of the genus Phyllidia (those that were previously named Fryeria) where instead it opens in the posterior midline below the mantle -ventrally. All phyllidiids feed upon sponges and are extremely slow moving.