トリガイの生態学的研究-I

成長について

抄録

A study on growth of Fulvia mutica (R_EEVE) from Suo-dada, Inland Sea of Japan was carried out. The results are as follows:
(1) Ring formation of shell of this bivalve seems to take place once in a year, during the months August-January in the first ring, and April-January in the second and other ones. Causative factors for ring formation appear to be water temperature and physiological rhythm of spawning.
(2) Shell-length becomes about 69mm., 85mm. in one and two full age respectively. In shells of ages more than three, shell-length is above 85mm.