抄録
Juveniles less than 20mm total length (TL) were collected by hand beam trawl from July through October. Small-sized fish 30 to 50mm TL began to be recruited to the catch by boat seine from August through September. Although they showed annual fluctuation of pattern in the length frequency distribution, small-sized fish grew up to large-sized fish from 50 to 70mm TL in spring through summer of the next year. A negative relationship between population density and growth in weight was observed. The spawning season is estimated to extend from May through September judging from the seasonal change of a gonadsomatic index. Some small-sized fish recruitd in summer also had well developed gonads. The rate of group maturity for females at around the end of August or time of recruitment showed annual variation, and was lower in 1977 when population density was higher than in other years.
