Abstract

An alternative method was used to estimate size at maturity for jack mackerel. This method considers relative oxygen consumption as a function of body weight and the consistency of relative oxygen consumption at the size at first maturity and at the asymptotic size in teleosts. Variance in the estimation was evaluated with the Monte Carlo method and considering the uncertainty in the parameters of the length-weight relationship and relative oxygen consumption. Size at first maturity was estimated to be 25.5 cm fork length (17.7-31.3 cm), which was similar to other estimates made using histological analyses of mature females. The method was applied to other species with the objective of demonstrating its usefulness for estimating size at first maturity in fishes.