抄録
In order to establish a method to estimate population fertility through the survey of commercially caught dab, research on maturation and spawning experiment through rearing fish were carried out. In the course of the former research age, growth by sexes, spawning season, regression of fecundity on body length, proportion of females participating in spawning, etc. were made clear. Through the latter experiment the pattern of maturation and oviposition and the relation between fecundity and fertility were disclosed. As a result, it was recognized that the type of maturation and oviposition of the dab is the bimode-split-batch spawning and the fecundity approximately equals the fertility. Considering the results together, a method to estimate the population fertility is proposed.
