三陸地方南部の河川残留型サクラマスの成長〔英文〕

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In order to clarify the growth pattern of the fluviatile form masu salmon in the southern Sanriku district, a total of 342 individuals were collected from 1984 to 1989 at five rivers. One hundred and thirty-six males and 110 females of fluviatile form (including the individuals before differentiation into the sea-run and fluviatile forms) were sorted by body shape, coloration, fork length mode and histological observation of ovaries, and used for calculation. Age was determined on the basis of the scale pattern and fork length composition. Three general growth equations were calculated by the nonlinear least squares method using basic data on fork lengths by sex and months of age of the fluviatile form. The von Bertalanffy growth equation was selected as the most suitable one: male, Lt=21.93[1-exp{-1.003(t-0.1961)}], female, Lt=24.12[1-exp{-0.8210(t-0.1431)}], where Lt indicates the fork length in cm at age t (year). The fitness to growth equation was poor in old males and females. Males mature and die one year earlier than females. It seems that the process of maturation exerts an influence on the differences between the sexes on the growth pattern.
日本水産學會の論文