JACKS

Family Carrangidae

Jacks are a highly specialized, powerful swimming fish, more at home in the open ocean than near the shore. All have very streamlined bodies with a narrow tail base and forked tail. The pectoral fins are scythe shaped and most species look like the tuna family, although much slimmer. Most of the species are fish hunters and are themselves an important source of food for human consumption.

BLUE RUNNER

Caranx crysos

This species of jack generally grows to around 35cm (1ft 2in) and has a distinctive arched lateral line. Silvery reflective, it gives a blue appearance and is a creature of the open ocean. Ecology: It is rarely seen close to shore but will frequent offshore reefs which have vertical walls. It hunts along the walls in small packs, rounding up smaller shoals of sardines and the like, before attacking them in an organized frenzy.

CREVALLE JACK

Caranx hippos

Growing to around 60cm (2ft), it is very rare that this fish attains a larger size owing to overfishing. It is a highly prized species. All members of the species share a common shape. Ecology: Crevalle Jacks only form groups when they are young and rarely venture inshore. Adults are solitary and wide ranging throughout the region.

MEDITERRANEAN AMBERJACK

Seriola carpenteri

These amberjacks grow to around 45cm (1ft 6in) and, although very similar to the Great Amberjack, this species is distinguished by the much lighter yellowish markings on the head and along the flanks. The pectoral and anal fins are also tinged yellow. Ecology: Little is known of its distribution, but it feeds on squid and small fish which are hunted in small packs.

GREAT AMBERJACK

Seriola dumerili

Growing to over 1.50m (5ft), the Great Amber-jack has a distinctive dark flash of yellow or tan, which traverses the eye and spreads along the top of the body. It hunts in small packs and is hunted by other jacks and even Barracuda. Ecology: The hunting packs work quite close to the edge of the reef and around shipwrecks, rounding up schools of smelt and bogue before attacking with lightning speed.