北海道木古内湾におけるアイナメHexagrammos otakiiの年齢と成長

Hexagrammos otakii

日本水産増殖学会

水産増殖

Age and growth of fat greenling Hexagrammos otakii collected from Kikonai Bay, Hokkaido were examined. Observation of otolith margin verified that annuli (outer margins of the opaque zone) were chiefly produced between August and September. It was found that the surface method tended to underestimate the age of fat greenling older than 6 years, comparing with the cross section method. Growth of fat greenling was expressed by the von Bertalanffy asymptotic growth function as SLt=435.0 (1-exp^[-0.234(t+1.387)]) for males and SLt=564.6 (1-exp^[-0.138(t+1.927)]) for females, where SLt is the standard length (mm) at estimated age t (years). A significant difference was found in parameters of growth equation between both sexes. It seems that the growth rate of fat greenling in this study area is relative low, because of low temperature during the winter.