Species-specific predation on amphipod crustacea by the pinfish Lagodon rhomboides: Mediation by macrophyte standing crop

The amphipod species consumed by Lagodon rhomboides represented only a small subset of the amphipod assemblage available at three seagrass habitats in Apalachee Bay, Florida (USA). Predatory preferences were related most closely to the microhabitat of prey species and were unrelated to amphipod abundances. Important prey species were all epifaunal types. Consumption of preferred amphipod species was non-selective at a site with sparse macrophyte cover, but selectivity increased with macrophyte biomass. The amphipod species that were preferentially selected as prey by pinfish correspond with those that have been suggested as being limited by fish predators. It was suggested that mediation of predator behavior by physical structure in seagrass meadows may play an important role in the regulation of species richness and abundances. Species-specific identification of prey is recommended for food-habit studies.