Distribution and growth in juveniles of the squid Berryteuthis magister (Cephalopoda, Gonatidae) in the western Bering Sea

Seasonal distribution, size composition, age structure and growth of Berryteuthis magister juveniles (mantle length from 20 to 130 mm) were studied in the western Bering Sea (from 1700E to 179°W) between June and October 1994. According to the analysis of 1030 statoliths, the juveniles hatched from December to June with a peak in February and March. Growth data for different seasonally hatched groups were best fitted by an exponential function, summer-hatched juveniles demonstrated the fastest growth. B. magister attained the length at which it recruits (130 mm mantle length) at an age ranging from 140 to 200 days. Comparison of variability of both juvenile age structures and geostrophic currents in the region revealed that the Eastern Bering Slope Current (EBSC) was the main carrier of B. magister juveniles from the spawning grounds to the western Bering Sea. Seasonal variability of the EBSC determined the differences in juvenile migratory patterns. During its intense stage in May-June, the EBSC transported winter-hatched and spring-hatched juveniles first to the eastern part of the region and then westward along the slope. During its relaxed stage in July-September, the EBSC carried spring- and summer-hatched juveniles across the deep-water part of the Aleutian Basin directly to the western part of the region