The Feeding Ecology of Four Species of Mojarras (Family: Gerreidae) Inhabiting a Brackish Water Stream in Jamaica

Abstract The feeding ecology of four co-occurring mojarra species, Eucinostomus argenteus, Diapterus auratus, Gerres cinereus, and Diapterus rhombeus in a shallow, brackish water, tropical stream on the south coast of Jamaica was studied. Stomach content analyses were performed, and these revealed that the fishes have a primarily zoobenthic diet. Both juveniles and sub-adults of the four species feed significantly on cyclopoid copepods, but in varying amounts. Invertebrate eggs, nematodes, algae (both filamentous and unicellular), and amorphous organic matter were shown to be of significant importance in the diets as well. The working hypothesis is that these four species of mojarras vary their diet interspecifically and intraspecifically to decrease competition within this habitat.