Growth of long-finned squid, Loligo peali, in the northwest Atlantic

The application of statolith ageing techniques to long-fined squid, Loligo pealei, suggests that this species has a life span of less than one year and grows more rapidly than preiously thought. In this study we provide direct estimates of growth for long-finned squid in the northwest Atlantic based on a data set of 353 animals aged by counting putative daily statolith increments. We examine empirical patterns in length and weigth at age and estimate parameters of a general growth model. The results indicate that growth rate increases rapidly as squid age and that growth in length and weight is expotential. Although there is substantial heterogeity in L. pealei size at age, sexual dimorphism is evident: males grow more rapidly than do females and achieve lager sizes. Back-calculated hatching dates show that L. pealei spawning is not restricted to spring through late-autumn, as previously supposed, but occurs durin winter months as well. Differences between growth rates of squid hatched during June-October and November-May are suggested and lend support to the hypothesis that growth can be influened by seasonal environmental condititions. We discuss the practical impilcations of our findings for the assessment and management of the long-finned squid stock in the northwest Atlantic