Piscivory and prey size selection in young-of-the-year bluefish: predator preference or size-dependent capture success?

Young-of-the-year bluefish Pomatomus saltatrix become piscivorous at a very small size/age.When feeding on Atlantic silversides Menidia menidia in the laboratory, bluefish forage in groups and, unlike many other piscivores, tend to attack their prey tail-first.Attack distances, times and velocities as well as attack rates were not size-dependent Handling tlmes and attack success rates, howcver, were strongly determined by both predator and prey slze When given a choice of silverside sizes, all bluefish sizes consumed primarily small prey.These results suggest that bluefish attack all prey sizes upon encounter but capture primarily small prey.Size selectivity may be a passive process mediated by differential size-based capture success