AGE AND GROWTH OF JAPANESE FLOUNDER PARALICHTHYS-OLIVACEUS IN THE SEA OF SOUTH-WEST KYUSHU, JAPAN

Age and growth of Japanese flounder Paralichthys olivaceus were studied with 198 females and 107 males, totaling 305 specimens (265-875 mm in total length) collected in the sea of south-west Kyushu. Judging from changes of the marginal growth index, age marks were formed during the period from January to April in the spawning season. Though significant data was not obtained in males due to shortage of specimens, the growth of females was expressed with the Bertalanffy curve of L(t) = 840.45[1-exp {-0.406(t+0.067)}] (L(t), total length; t, age). The growths of Japanese flounders around Japan were compared among 19 localities, and divided into three groups: the slow growth in the Touhoku and Hokuriku Districts and the Seto Inland Sea, the intermediate growth in the Sanin District, and the fast growth in the Pacific coast south of the Kantou District and around the Kyushu District.