Seasonal loss of alarm substance cells in North American cyprinoid fishes and its relation to abrasive spawning behaviour

Histological examination of skin from preserved specimens of nine species of cyprinoids and one catastomid revealed seasonal loss of alarm substance cells in the males from seven cyprinoid species and reduction in the females from two species. Six of these species have abrasive spawning behaviour, while the behaviour of the seventh species has not been extensively studied. This is taken as tentative evidence that seasonal alarm substance loss is related to abrasive spawning behaviour. Several species also show seasonal changes in mucus production and epidermal thickness.