Koji Takeno，Mamoru Yoshiya，Toshiaki Miyajima

　

Nippon Suisan Gakkaishi, 67(6) : 1061-1064 (2001)
　

Meristic characters were studied in Japanese flounder Paralichthys olivaceus collected in western Wakasa Bay with the focus on two distinct populations. The numbers of dosal and anal fin rays were compared between immature and adult fish collected from 1994 to 2000. Matured adult fish collected in the spawning season had significantly lower number of dosal and anal fin rays compared to the immature fish collected in the same area. Considering the previous reports which showed that there were two distinct populations as resident (lower fin ray number) and migrant (higher fin ray number), we speculated that the higher fin ray number population emigrates from western Wakasa Bay to the westward at one or two years old, whereas the lower fin ray number population stays in this area through life.