Basics of skin structure and function in elasmobranchs: a review.

In contrast to the bony fishes, particularly the teleosts, the integument of elasmobranchs is rather unknown. Therefore, a description of the basic structural and functional features of shark and ray skin is given, based on a review of the literature and published or unpublished findings of the authors. The latter aspect makes it possible to document in more detail the specific structure of the skin layers regarding, particularly, the epidermis and its cell spectrum, the more or less robust dermis with its specific features, the very special scales with their derivates and the sophisticated sensoric integumental equipment. As far as possible, all important structures are discussed including their typical biological functions and results from applied scientific work. To some extent the information given is evaluated as compared with the much broader knowledge from the Osteichthyes.