Growth and Hypothetical Age of the Newfoundland Bait Squid Illex illecebrosus illecebrosus

Abstract

Length measurements of a migrant ommastrephid squid Illex illecebrosus illecebrosus (Le-Sueur), in Newfoundland east coast waters indicated that only 1 modal class was present except in Nov. of some years. Average lengths and weights of random samples taken monthly from May to Nov. indicated also that growth was very rapid during this period. The majority of the population, averaging 140 mm in mantle length (54 g whole weight) in both sexes in May, reached maximum mantle lengths of 260 mm in males and 300 mm in females by Oct. (weights of 360 and 550 g in males and females respectively). By fitting growth curves to these data, and by observations on sexual maturity, the approximate times of birth and mortality were extrapolated. Spawning and probable subsequent mortality of this squid was estimated to be at not more than 2 yr and most probably at only 1 yr of age.