1968 年 34 巻 6 号 p. 457-461
In the studies on the propagation of an abalone, H. diversicolor supertexta, it is essential to estimate the age of the shell. The size of the one-year-old specimen, however, has not been definitely settled yet.
In the present paper, estimation of its size was made by the measurement of shells both reared in the laboratory and collected monthly from the natural bed in three years (Figs. 1 and 3).
The youngs reared in the laboratory reached 21.8-26.8mm (2.48mm in average) in shell length by the end of first year (Fig. 2). The results of the consecutive observations of size frequency distribution are shown in Fig. 3. The one-year-old specimens collected from natural bed are estimated as 22.0-27.9mm in shell length.