Genetic differences are significant between Neon flying squids from the Indian Ocean and the North Pacific Ocean (Kurosaka et al, 2012). In the last region, four populations are identified in the two seasonal cohorts which demonstrate different life-history traits and geographic distributions – central and east stocks of the fall cohort, west and central-east stocks of the winter–spring cohort (Bower and Ichii, 2005; Chen, 2010; Ichii et al, 2011) – but further analysis is required to understand the population structure (Kurosaka et al, 2012). The western winter-spring cohort is here regarded as a single stock (Xinjun et al, 2008).