Japanese flying squid, Japanese Common Squid
Japanese common squid, Pacific flying squid
Japanese flying squid (Todarodes pacificus) is an important commercial species caught by Japanese, Chinese, Korean and Russian fishermen in the Northwest Pacific Ocean, Sea of Japan, Yellow Sea, and East China Sea (FAO 61; major fishing area 61) Wang et al. (2018). According to these authors, genetic analyses of population structure are somewhat limited but they suggest the existence of two distinct breeding groups defined by their spawning times: (1) the fall spawners, and (2) the winter, summer, and spring spawners combined. The fall breeding stock spawns mainly from October to December and is distributed and landed chiefly in the Sea of Japan; while the winter and spring breeding group spawns mainly from January to March and performs a counterclockwise migration around the Japanese Islands. Fall spawners also show some unique life history characteristics, such as comparatively large body size and low individual fecundity, and hydrographic conditions may keep larvae within the central and southern parts of the Japan Sea. The fall and winter breeding groups support large-scale fisheries, while the summer spawning breeding group supports only small-scale fisheries.
Thus, this species can be classified as a transboundary stock, in that is to be found in different EEZs, extending also into the high seas, adjacent to the coastal states' EEZs.
The Fisheries Research Agency of Japan performs separate stock assessments of the fall and winter spawning breeding groups, while a single TAC is set for the stock (including the two breeding groups).