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

Abstract

Histological examination of skin from preserved specimens of 9 spp. of cyprinoids [Couesius plumbeus, Nocomis biguttatus, Notropis cornutus, Pimephales vigilax, P. notatus, Campostoma anomalum, Rhinichthys cataractae, Semotilus atromaculatus, S. margarita] and 1 catastomid [Catostomus commersoni] revealed seasonal loss of alarm substance cells in the males from 7 cyprinoid species and reduction in the females from 2 spp. Six of these species have abrasive spawning behavior, while the behavior of the 7th species has not been extensively studied. This is taken as tentative evidence that seasonal alarm substance loss is related to abrasive spawning behavior. Several species also show seasonal changes in mucus production and epidermal thickness.