Size and age at sexual maturity of Atlantic argentine,Argentina silus: a critique

Synopsis A recent analysis of size and age at sexual maturity ofArgentina silus on the Scotian Shelf is invalid because field maturity stage data collected during the non-spawning, quiescent stage of the reproductive cycle were unreliable for distinguishing between immature and resting mature stages. Thus two-thirds of the data used must be discounted. Utilization of different length measurement criteria for different years, for which no correction is made, could introduce substantial error in length at maturity estimates based on the remaining data. Age data collections were restricted to one 12 month period and thus were inadequate to characterize age at maturity by 5 yr time periods as attempted in this analysis. No attempt is made in the analysis to determine whether available samples adequately represent the population with regard to maturity i.e. whether immature and mature fish of the same length had an equal probability of being sampled. It is demonstrated here that maturity ogives can differ greatly depending on assumptions made concerning the representativeness of samples. Many of the criticisms made are likely valid for a series of papers on maturity of Atlantic coast fishes by the same author.