Growth and Reproduction of Three Species of Embiotocid Fishes in the Zostera marina Belt of Odawa Bay

Abstract

The purpose of the present paper is to elucidate the seasonal growth pattern and the mechanism of the reproductive phase of three species of embiotocid fishes, Ditrema viridis, Ditrema temmincki and Neoditrema ransonneti, in Odawa Bay. Two regression lines fitted the data of relations between body length and body weight for females and two or three regression lines were applied to the data of relations between total body length and body weight for embryos at the stage of gestation in the ovary of female mother. The growing season was seen to occur generally from May to September and the non-growing season from October to February of the next year with slight differences according to species and year class. A time lag of about six months between males and females of D. viridis and D. temmincki was seen in the reproductive cycle and the fat content had a close relation to sexual maturation. A common balance between the number of embryos and the size of young at birth was recognized in both D. viridis and D. temmincki. © 1980, The Japanese Society of Fisheries Science. All rights reserved.