DISTRIBUTION, STOCK STRUCTURE, AND GROWTH OF THE SQUID BERRYTEUTHIS MAGISTER (BERRY, 1913) (CEPHALOPODA, GONATIDAE) DURING SUMMER AND FALL IN THE WESTERN BERING-SEA

Distribution, abundance, and length-frequency composition of schoolmas ter gonate squid, Berryteuthis magister, were studied during seven tra wl surveys in the western Bering Sea between June and November 1993. S tatolith age analysis was undertaken for 1,381 B. magister to estimate age, stock structure, and both growth and maturation rates. Three kin ds of growth increments were revealed in B. magister statoliths. Daily periodicity of the second-order increments was confirmed by two indep endent, indirect methods. According to our data, B. magister live > 1 yr; the oldest specimen was about 16 months old. Berryteuthis magister is a slow-growing and slow-maturing squid, and males exhibit slower g rowth and earlier maturation than do females. Growth in length was bes t described by a logistic curve, with a larger asymptotic parameter fo r females. In summer, concentrations of B. magister were low within th e whole region, whereas in September-October squids aggregated into de nse shoals over the continental slope of the Navarin-Olyutorsky region and Olyutorsky Bay. Stock structure of B. magister was complicated: e ach month, from 5 to 12 (usually 7-8) monthly classes of squid were en countered in the western Bering Sea. Three seasonal groups of B. magis ter occurred in the region: winter-, summer- and fall-hatched squids u tilizing resources of the continental slope in different ways. A possi ble life cycle for the B. magister fall-hatched group includes a longe vity of ca. 2 yr: 6 mo of embryonic development and 18 mo of postembry onic growth.