Epidermal fine structure of the teleost Esox americanus (esocidae, salmoniformes)

Abstract

The epidermis of Esox americanus consists of filament-containing cells, secretory cells, and occasional chloride cells. The filament-containing cells are the most numerous with three distinct types belonging to basal, mid and surface layers. These cells have predominately a structural role, although the surface cells probably contribute to the formation of the cuticle. The structure of the basal cells also suggests other activities. The surface of the epidermis is characterised by concentric patterns of fingerprint-like folds on top of each cell, a feature found in other teleosts. Two types of secretory cells are present; the typical gobletlike mucous cell, and another type not previously described but also considered to produce mucus. The diversity of cell types reflects the numerous functions of teleost epidermis. However, although the epidermis of E. americanus is distinct from other teleosts, gross differences in function are not envisaged.