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Abstract
Elongate ilisha Ilisha elongata is a commercially important fishery resource in both Japan and China. Age and growth of the species were investigated by scale analysis from June 1996 to July 1997 in Ariake Sound, Japan. Scale annuli were formed once a year mainly between June and July. The age was 1-6 years for both male and female individuals. There was no significant difference in the regression of fork length (FL) on scale radius (R) between sexes by a covariance analysis. The combined sex von Bertalanffy growth equations were expressed as L ^sub t^ =495.4×(1-e^sup -0.3176(t+0.4108)^ ), where L ^sub t^ is FL in mm at age t. Comparison of the age and growth among different populations from coastal waters in the western North Pacific Ocean suggested that the FL of the Ariake population is the smallest at each age. The spatio-temporal variations in growth are possibly relevant to environmental conditions of the growth grounds of subadults; however, there was no gradient change in the growth of I. elongata with latitude. Water temperature may not be the main factor affecting the growth of this species. The growth of the tropical population from Sarawak differs greatly from those of temperate and subtemperate populations, which implies genetic variation or phenotypic plasticity in different climate zones.[PUBLICATION ABSTRACT]