Age, Growth and Reproductive Characteristics of the Yellow Sea Bream Dentex tumifrons in the East China Sea

Abstract

We examined 1,377 specimens of the yellow sea bream Dentex tumifrons caught by bull trawl in the East China Sea and landed at Nagasaki Fish Market from March 1993 to May 1994, and obtained information about age, growth, and reproduction. Ages were determined by scale readings. The relationship of fork length to scale radius was significantly different in males and females. Rings on the scales formed twice a year, spring and autumn. Growth equations are given for spring and autumn spawned fish and for males and females. It is inferred that the calculated fork lengths at age in the present study were smaller than those reported 30 years ago from the East China Sea, in other words, the growth rate appears to have slowed. From the monthly changes of GSI, spawning is estimated to occur twice a year, in spring and autumn. Egg diameter distribution and histological observations of the ovaries suggest that each fish spawns several times during the spring and the autumn spawning season.