 The diets of these top predators of reefs are composed almost totally of fish, cephalopods, and occasionally shrimp.Large barracudas, when gorged, may attempt to herd a school of prey fish in shallow water where they guard over them until they are ready for another hunt.Barracudas are scavengers, and may mistake snorkelers for large predators, following them in hopes of eating the remains of their prey.