Distribution:
Atlantic, Indian and Pacific Oceans; rarely in brackish water.
Habitat:
Tropical and temperate nearshore waters, commonly along reefs, a few species in oceanic waters near the surface; juveniles occasionally in estuaries.
Remarks:
Some of these species are known as amberjacks, pompanos, moonfishes, pilotfishes, rudderfishes, scads, and trevallies, the jacks have a variety of body types. They are usually compressed and have small cycloid scales. Many species have scales on the lateral line modified into spiny scutes. The anal fin generally has two anterior spines separate from the rest of the fin.
Jacks are efficient swimmers, often forming large schools that roam great distances. This family is known for its distinctive "carangiform" locomotion, or rapid side-to-side movement of the rear body and tail. Typically, jacks have slender caudal peduncles and strongly forked caudal fins.
Jacks are pelagic predators and zooplanktivores; however a few species root through the sand. They feed primarily on small fishes and invertebrates.
This family consists of four subfamilies: Trachinotinae, Scomberoidinae, Naucratinae, and Caranginae, and comprises about 32 genera and 140 species. Many members of this family are important foodfishes.
References:
Allen & Robertson 1994;
Helfman et al. 1997;
Nelson 2006;
Smith-Vaniz, pp. 1426-1468, in: Carpenter 2002