Size composition of neon flying squid based on Chinese squid jigging survey in the Northwest Pacific Ocean

This report presents an updated analysis of the size composition, length-weight relationship, and sexual maturity of neon flying squid (Ommastrephes bartramii), based on squid jigging surveys conducted by the Chinese research vessel “Songhang” in the Northwest Pacific Ocean during the summer months (June to August) from 2021 to 2025. A total of 3,908 neon flying squid individuals were measured during the survey period. The results showed that the mantle length of the sampled neon flying squid ranged from 110 to 490 mm, with a unimodal distribution where the vast majority of individuals were concentrated between 180 and 250 mm. Most of these medium-sized individuals remained at immature stages (maturity stages 1 and 2), indicating that the summer aggregations in the surveyed high-seas fishing grounds were primarily composed of the winter-spring cohort.