Bluefin Trevally, Caranx melampygus
The Bluefin Trevally, Caranx melampygus, whose common Spanish name is “Jurel Aleta Azul”, is a member of the Jack or Carangidae Family, known collectively as “Jureles and Pámpanos” in Mexico.
The Bluefin Trevally has an overall “jack-like” appearance with a moderately compressed deep oblong body with a width that is 33 to 37% of standard length. Their head and body are bronze in color with a blue tinge and the mid to rear portion of the body is covered with small black dots. The anal, caudal and second dorsal fins are electric blue. The pectoral fins of juveniles are yellow. The Bluefin Trevally has an angular head profile. The anal and dorsal fins have elongated front lobes and the pectoral fins are disproportionately long. They have 17 to 21 gill rakers and 27 to 42 strong scutes. The lateral line has a pronounced anterior arch. The body is covered with small scales.
The Bluefin Trevally reach a maximum of 117 cm (46 inches) in length. They are associated with reefs with the adults being found in deep water, at a maximum depth of 750 feet, traveling either solitary or in small schools. The juveniles can be found seasonally in large numbers in shallow sandy inner flat environments and they are known to enter estuaries. They are opportunistic predators feeding on benthic and pelagic fishes as well as squid and crustaceans. In Mexican waters of the Pacific the Bluefin Trevally has a very limited range being found in the southern extreme of the Sea of Cortez; I have a fish in my possession that was caught forty miles north of Cabo San Lucas along the southwest coast of Baja establishing a range extension for this species.
The Bluefin Trevally can be confused with the Black Jack, Caranx lugubris (all fins grey-black), the Golden Trevally, Gnathanodon specious (yellow fins and large dark spots on its side), and the Island Jack, Carangoides orthogamus (six oval yellow spots on its sides).
In some parts of the world (the Eastern and Central Pacific and the Indian Ocean including the eastern, northern and western coastal waters of Australia) the Bluefin Trevally is a popular and prized game fish for recreational anglers. They are also considered to be an excellent food fish. Efforts are currently on-going in Hawaii to raise this species via aquaculture.