Epidermal cellular proliferation and differentiation in sexually mature male Salmo salar with androgen levels depressed by oil.

Sexually mature male Salmo salar exhibit epidermal thickening and an increase in goblet cell concentration during the spawning season. The ventral skin, which is likely to experience most abrasive contact during the spawning period, has the thickest epidermis and the greatest goblet cell concentration. Following exposure to crude oil there is inhibition of cellular proliferation and elongation associated with epidermal thickening, and also inhibition of mucigenesis. Data on the androgen levels in these fish, and data from earlier studies involving treatment with hormones, indicate that oil-related epidermal effects during the spawning period are most likely systemic in origin, probably arising from reduced plasmatic androgen levels.