Differences in the distribution of the neon flying squid by spawning cohort in the North Pacific Ocean based on the results of age determination using statoliths

The hatching month and spawning cohort composition of neon flying squid in the North Pacific Ocean were estimated by age determination using statolith of squid caught by Japanese survey. Squid caught at 144° 00’ E and 155° 00’ E survey lines were mostly the winter-spring cohort, while squid caught at 170° 00’ E to 178° 00’ E survey line were both the autumn and winter-spring cohort. Squid caught at 144° 00’ E and 155° 00’ E survey lines were mainly hatched between February and April. Squid caught at 170° 00’ E to 178° 00’ E survey line were mainly hatched between September and November and between January and March. These results suggest that the catch of neon flying squid caught in the water east of 170° 00’ E includes both the autumn and the winter-spring cohort.