Ontogeny and sex alter the effect of predation on body shape in a livebearing fish: sexual dimorphism, parallelism, and costs of reproduction

摘要: Predation can cause morphological divergence among populations, while ontogeny and sex often determine much of diversity individuals. We used geometric morphometrics to characterize body shape in the livebearing fish Brachyrhaphis rhabdophora test for interactions between these three major shape-determining factors. assessed variation juveniles adults both sexes, populations from high- low-predation areas. Shape differed significantly predation regimes all regardless sex. As males grew matured into adults, ontogenetic trajectories were parallel, thus maintaining differences adult environments. However, females environments followed a different pattern. matured, converged so that less pronounced mature predator nonpredator Convergence female may indicate trade-off optimal evasion versus required mode reproduction.