This study describes the abundance of exotic amphipods associated with aquaculture systems and their possible use as animal food. Of the six amphipod species recorded in fish aquaculture systems, Jassa marmorata (Holmes, 1903) is the most abundant. Differences were established in the species' abundance and between sites; however, no variation was observed in species composition. Feeding trials were carried out on paralarvae of the "baby octopus" Robsonella fontaniana (d'Orbigny, 1834) to determine the potential use of Jassa marmorata as animal food.