Title Environmental Regulations of Reproductive Cycles in Teleosts
Authers Akio SHIMIZU
Keywords water temperature, photoperiod, maturation, reproduction, annual cycle, spawning period, refractory period, circa-annual rhythm
Citation Bull. Fish. Res. Agen. supplement No. 4, 1-12, 2006
Abstract
This review summarizes the knowledge of environmental regulation of annual reproductive cycles in teleosts displaying various spawning periods. Warm temperature is the important factor which causes initiation of the spawning period in both of spring spawning and "spring-to-summer" spawning teleosts, and high temperature during summer is the predominant factor that causes termination of the spawning period in the spring spawning species. In the spring-to-summer spawning species, short daylength in autumn is the predominant factor that causes the termination of the spawning period. In autumn spawning teleosts, short daylength is the predominant factor that causes initiation of the spawning period, and low temperature during winter is the predominant factor that causes the termination. In summer spawning, spring and autumn spawning, and "winter-to-spring" spawning species, changes in water temperature seem to be the important factors for both initiation of and termination of the spawning period, although daylength might also be concerned in some cases. In several cases regardless of the types of the spawning period, internal factor such as circa-annual rhythm might be concerned with the environmental regulation, through changes in photoperiodism appearance and/or existence of a refractory period.
URI http://www.fra.affrc.go.jp/bulletin/bull/bull-b4/02.pdf