Foraging interactions among three benthic fish in a Posidonia oceanica reef lagoon along the Tyrrhenian Coast

Three benthic predators Coris julis, Symphodus cinereus and Mullus surmulet us in a Posidonia oceanica reef lagoon of the Tyrrhenian coast had a broad diet, including hard-bodied invertebrates such as crustaceans and molluscs, but revealed consistent interspecific differences. Diet overlap was greate r between C julis and M. surmuletus in comparison to other combinations. Ai l three species were diurnal feeders, but with different daily patterns of foraging based on different prey availability. There was a general spatio-t emporal correlation in non-foraging activity among the three species, but f oraging activity was correlated only between C. julis and the other two spe cies, but not between S, cinereus and M, surmuletus. There was heterospecif ic aggregation during foraging between C. julis and M, surmuletus, and poss ibly a scrounger-producer relationship between them. Fights between C. juli s specimens related to foraging activity were common, but not between speci es. These results support the view that differences in spatio-temporal orga nization of activity, and interactions during foraging, can contribute to r esource partitioning among syntopic populations of fish belonging to the sa me trophic group. (C) 1999 The Fisheries Society of the British Ides.