Comparative diets of macrocrustacean species from the San Jorge Gulf, Argentina

Macrocrustaceans have a central role in marine food webs given that they often dominate benthic communities and serve as link between basal levels and top predators. The aim of the present study was to describe the diet of six macrocrustacean species (Eurypodius longirostris, Libidoclaea granaria, Lithodes santolla, Grimothea gregaria, Peltarion spinosulus and Pterygosquilla armata) from San Jorge Gulf, Argentina. Stomach contents were analyzed in 331 individuals and the frequency of occurrence and relative abundance of the different prey items were estimated. Differences between the diets of the studied species were established by using an analysis of similarity (ANOSIM), and prey items responsible for dissimilarities were identified by a similarity percentage analysis (SIMPER). A high diet overlap was observed among most species, probably because crustaceans and particulate organic matter constituted very abundant prey items for the different species. The presence of sediment in the stomachs of E. longirostris, G. gregaria and P. spinosulus suggests that these species have a deposit feeding habit. The diet overlap may be the result of the generalist habit of species studied (except for P. armata). The deposit feeding strategy would be favoured by the high secondary productivity of the infaunal community of the San Jorge Gulf.