The influence of photoperiod on sexual development in underyearling rainbow trout, <i>Salmo gairdneri</i> Richardson

Abstract

Photoperiods of 19 h light or more induced sexual maturation in male underyearling rainbow trout but did not influence maturation in the females. Early maturation was not a consequence of the increased growth under long photoperiods. The rate of mortality was much higher in the early maturing males than in the immature fish.