Histology and ultrastructure of the skin of Lepadichthys lineatus (Gobiesocidae: Teleostei)

Abstract

The skin of the Red Sea clingfish Lepadichthys lineatus Briggs, 1966, which lives on shallow-water crinoids, consists of a continuous layer of giant mucus-producing cells. Upon stimulation, these cells are able, in seconds, to envelope the fish entirely with a thick layer of their secretion. The cells are 75 to 290 μ high, and are enveloped by septa of compressed epithelium. They rest on a strong collagenous layer, and extend to the skin surface, where they open. The nuclei of the giant cells are large, and irregularly shaped; their cytoplasm has a very extensive endoplasmic reticulum and undergoes deep structural changes during maturation. Their ability to produce large amounts of mucus seems to be an adaptive device to protect the fish from contact with the rough surface of the crinoid host.