Great barracuda eat other fish. They are piscivorous at all ages. Their large teeth are quite useful for this purpose. They have a large gape which allows them to feed on very large fish by chopping them in half. They eat what they can catch using their combination of a sit-in-wait and active predator style. As juveniles, these fish compete with needlefishes and small snapper for food. This consists of killifishes, herrings, sardines, gobies, silversides, anchovies small mullets, and lizardfishes to name a few. As the fish get older and bigger, they may compete with larger fish like mackerel, or even dolphins, depending on their habitat (Paterson 2000).
Sphyraena barracuda will feed on both bottom-dwelling species as well as species of the higher water column (Paterson 2000).
They have the narrow head-on profile and the silvery color which reduces their visibility to prey. It has been observed that great barracudas herd schools of fish into shallow water and guard them. They will do this until their last meal has been digested and they are hungry again (Norman 1958).