La pelle delle torpedini (Torpedo marmorata Risso e Torpedo ocellata Rafinesque) con particolare riguardo all’istochimica del secreto epidermico e dei raggi cartilaginei delle pinne.

The aim of this study is to observe morphological and histochemical dif¬ferences between dorsal, ventral skin and pectoral fin skin as well as the condrogenes•s of cartilaginous fin rays occurring in the dermis of Torpedoes. Pieces of dorsal, ventral and pectoral fin skin, were stained with histochemical methods for neutral and acid polysaccharides, for basic and sulphated proteins for lipids and for some enzymatic activities. The dorsal epidermis can be distinguished in three layers: basal, middle and superficial. The basal layer consists in columnar cells negative to the histochemical reactions performed. In the middle layer there are three different cellular types: the epidermis cells which show mucopolysaccharide-protein complexes, numerous typical large mucous cells which contain mucopolysaccharidic materials and some serous cells with proteic content. In the dermis a dense layer of melanophore cells is present. The ventral skin shows less abundant mucous cells than the dorsal one:and the melanophore cells are absent. In .the pectoral fin skin there are cartilagi¬neous rays in the dermis that show condrogenetic activity also in adult animals.