Discodorididae Family

Family Discodorididae

Discodorids typically have an ovate body that in most is usually quite flattened in profile however some genera do present a high dorsum. The mantle is broad and thick with the skirt usually covering the whole body (including the tail) and containing spicules arranged in complex networks. There is a variety of mantle surface textures including smooth, ridged, tuberculate, or even pustulose. Some species with very broad mantles are able to autotomize portion of the mantle skirt if aggravated. Sometimes the raised tubercles are girdled by a circle of spicules surrounding a central sensory structure and this whole organ is called a caryophyllidium. Small irregularly situated defensive glands are also present on the mantle a short distance in from the margin. The head is usually small and the distinct oral tentacles vary in form from conical, to tentacular, to large and flattened. The rhinophores are retractable into separate pockets often with raised sheaths and are lamellate. These pockets can have rims that are smooth, pustulose or papillate. The gills are located posteriorly on the dorsum, are usually tripinnate, and are able to retract into a pocket which can be protected by a raised sheath. The foot is large and all discodorids have a lateral split anteriorly producing an upper and lower lip with a vertical split in the upper lip giving left and right halves (philtrum). All feed upon sponges, with each species having a preference usually for one species of sponge only. Many species of the family Discodorididae are found intertidally.