Investigation on the early stages of the ommastrephid squid Todarodes pacificus near the Oki Islands (Sea of Japan)

The MOCNESS (Multiple Opening Closing Net and Environmental Sampling System) was used to investigate the distribution of the early life stages of the Japanese common squid Todarodes pacificus in the southwest Sea of Japan near the Oki Islands, a suspected spawning ground of this species. The largest catches of hatchling-sized paralarvae occurred at the surface layer (0-25 in), and paralarval mantle lengths increased with increasing sampling depth, suggesting that T pacificus paralarvae gradually descend in the water column life cycle as they grow. There was no clear difference in the horizontal distribution among the different size groups.