The western Sea of Japan stock of willowy flounder Tanakius kitaharai was analysed for stockrecruitment relationship using virtual population analysis. The biomass of spawning females increased from 417 t in 1998 to 1174 t in 2007, being stable at a high level in later years. Variation in recruitment (number of age 1 fish) were small, ranging from 16 .4 million in 1998 to 21.2 million in 2009. The Ricker type stock-recruitment model, R^^^=51.1 Pe^{-0.000945P}, was derived. An index of year class strength was evaluated from the relative distance from the Ricker curve, RR=(R-R^^^)/R^^^. Significant positive correlations were observed between RR and both sea water temperatue of the spawning ground and season. It was considered that recruitment success of willowy flounder may be enhanced by high temperatures.
sea water temperature
Tanakius kitaharai
virtual population analysis
willowy flounder