Testing predictions of length at first maturity of teleostean fishes, given their maximum length

Abstract

This contribution presents a test of a hypothesis published in 1984 that teleostean fishes mature and spawn when they reach the threshold value of LmaxD/LmD of 1.35 (95% CI: 1.22-1.53). Here, Lm is the average length at first maturity of the fish in a given population, Lmax is the maximum length reached by the individuals in that population, and D a parameter ranging between 0.3 and 1.2 in fish which relates their body size, via their gill surface area, to their oxygen consumption. The data analysed here, which include 120 Lmax/Lm pairs in 57 fish species from the published literature on marine and freshwaters in Southeastern Europe and West Asia, lead to a new ratio estimate of 1.44 (95% CI: 1.41-1.48), when all cases are given the same weight and 1.30 (95% CI: 1.17-1.43) when the phylogeny of the 57 species is explicitly accounted for. Both sets of results are within the confidence intervals of the earlier estimate and thus corroborate the above hypothesis.