A scanning electron microscope study of notum structures in some dorid nudibranchs (Gastropoda: Opisthobranchia)

Abstract

Skin structures of nine different species of dorid nudibranchs were examined at the scanning electron microscope and the light microscope levels. From these observations the animals are grouped into three categories.1. Dorids with spicule-supported tubercles carrying a sensory knob (Rostanga rubra, Jorunna tomentosa, Onchidoris sparsa, Onchidoris pusilla).2. Dorids with small sensory papillae set in pits and distributed randomly between projecting spicules (Aegires punctilucens).3. Dorids with tubercles differing in shape from one species to another, invested with numerous spicules but without conspicuous sensory structures. The tips of the tubercles do, however, contain single sensory epithelium cells (Archidoris pseudoargus, Acanthodoris pilosa, Onchidoris muricata, Onchidoris bilamellata).