Effects of hypophysectomy and ovine prolactin on the epithelial mucus-secreting cells of the Pacific staghorn sculpin, Leptocottus armatus (Teleostei: Cottidae)

Abstract

Although hypophysectomy did not affect the number of skin mucous cells of sculpins in 5% seawater (1.4‰ salinity), there were fewer mucous cells in the gills, compared with intact and sham-operated controls. Injections of ovine prolactin (10 μg/g) maintained the number of gill mucous cells of the hypophysectomized fish at levels near that of sham-operated controls. The results are discussed in relation to the possible involvement of mucus secretion in teleost osmoregulation. An index method for easily estimating the number of mucous cells in the gill is described and evaluated.