Jacks

The Carangidae are a family of ray-finned fish that includes the jacks, pompanos, jack mackerels, runners, trevallies, and scads. It is the largest of the six families included within the order Carangiformes. Some authorities classify it as the only family within that order but molecular and anatomical studies indicate that there is a close relationship between this family and the five former Perciform families which make up the Carangiformes. They are marine fishes found in the Atlantic, Indian and Pacific Oceans. Most species are fast-swimming predatory fishes that hunt in the waters above reefs and in the open sea; some dig in the sea floor for invertebrates.

Source: Wikipedia