Title A Review of the Reproductive Studies for Chub Mackerel in Relation to the Stock Assessment.
Authers Chikako WATANABE
Keywords reproduction, stock assessment, egg production method, batch fecundity, spawning frequency, chub mackerel
Citation Bull. Fish. Res. Agen. supplement No. 4, 101-111, 2006
Abstract
This review summarized the reproductive biology of the Pacific stock of chub mackerel in relation to the stock assessment by the Egg Production Method (EPM).
The main spawning period was in April in the 1970s when the biomass of chub mackerel was high, and in June in recent years when the biomass was low. On the other hand, the spawning ground has remained in the central part of the Pacific coast of Japan, around the Izu Islands, for the past 30 years. The depth and the water temperature of the spawning ground were estimated to be about 50m and 14-18℃respectively. The spawning time was estimated to be 20-24hr. The annual means of the spawning frequency varied from 0.17 to 0.34, and the individual batch fecundity varied from 14 to 150 thousand eggs/female.
This review also discussed the problems for applying EPM, and proposed incorporation of the reproductive biology in the process of the stock assessment and management of chub mackerel.
URI http://www.fra.affrc.go.jp/bulletin/bull/bull-b4/14.pdf