open access

https://hdl.handle.net/2115/38418

Distribution and Maturation of Adult Walleye Pollock in Autumn in the Japan Sea off Southwest Hokkaido

日本語

産卵回遊

1999-03-15

The Japanese Society of Scientific Fisheries

Bulletin of the Japanese Society of Scientific Fisheries

65(2)

223-229

In order to elucidate the association between the distribution and maturation of adult walleye pollock Theragra chalcogramma, otter trawl samplings were carried out in the Japan Sea off the southwest Hokkaido in October from 1989 to 1994. CPUE values of walleye pollock were significantly higher in the coastal region than those in the offshore region through the sampling years except for 1994. Proportions of males were significantly higher in the coastal region except for 1993 and 1994. Many males were nearly mature, and no differences in male gonad indices were found either between coastal and offshore regions or among the coastal areas. In contrast, females collected in the coastal region were more mature than those in the offshore region. Clear geographical differences in body length were not found either among males or among females. Sexual differences in reproductive behavior and maturity might be responsible for the skewed distribution pattern of adult walleye pollock in October.

学術雑誌論文

Version of Record

© 1999 The Japanese Society of Fisheries Science

0021-5392

AN00193422