Distribution of Todarodes pacificus (Cephalopoda: Ommastrephidae) paralarvae near the Kuroshio off southern Kyushu, Japan

The distribution and abundance of Japanese common squid [Todarodes pacificus (Steenstrup, 1880)] paralarvae off southern; Kyushu Island near the Ku-roshio were examined in relation to water types in the region. Surveys were conducted in 1996 and 1997 using paired, 70 cm diameter Bongo nets. Temperature-salinity plots from 0, 50 and 100 m depths were used to assign sampling stations to three water types: inshore, mixing and Kuroshio. In total, 4103 T. pacificus paralarvae were collected at 59 of 72 stations. Catch densities at positive stations ranged between 8 and 4282 ind./50 m(2) sea surface area. Catches during both years were highest in mixing waters, followed by inshore and Kuroshio waters. Total catches were highest just north of the oceanographic front at the inshore edge of the Kuroshio and declined with increasing distance away from the front. Catches of paralarvae less than or equal to 1.0 mm mantle length also peaked near the front. In both years, greater than or equal to 85% of all paralarvae and greater than or equal to 69% of those less than or equal to 1.0 mm mantle length occurred less than 25 km from the front. We conclude that most spawning off southwest Kyushu occurs near the frontal zone, where Kuroshio and inshore waters meet.