Reproductive relationships of the Pacific stock of Japanese anchovy Engraulis japonicus

The relationships between the number of parents, the egg production in the eastern area from the Shionomisaki of the Pacific water off Japan from 1978 to 1994, and the number of children, the cumulative egg produciton of progeny from 1978 to 1994 year-classes, of the Pacific stock of Japanese anchovy were investigated. We obtained the cumulative egg production of progeny from the egg production of the Pacific stock of Japanese anchovy divided by the ratio of relative annual fecundity estimated from past studies and the annual adult catch every year from 1978 to 1996. Reproduction relationships of 1978-1988 year-classes differed from 1990-1994 year-classes. The reproductive relationship of the former was constant when the stack abundance was low and that of the latter fluctuated when it was high.