The black jack is a large fish, and is confidently known to grow to a length of 1 m and a weight of 17.9 kg, although is more common at lengths under 70 cm. At least one source asserts a fish of 2.21 m has been reported, which if true would make the black jack the second largest species of carangid behind the yellowtail amberjack (2.5 m). The black jack has a similar overall body shape to the other members of Caranx, having an oblong, compressed form, with the dorsal profile more convex than the ventral profile. This convexity is most pronounced at the head, which slopes steeply downwards, giving the head profile a very angular appearance. The profile between the snout and the nape is concave, with this indent centered near the nostrils. The mouth is fairly large compared to other members of its genus and the maxilla extends to under the centre of the fish's eye. The upper jaw contains a series of strong outer canines with an inner band of smaller teeth, while the lower jaw contains a single row of widely spaced conical teeth. The dorsal fin of the black jack is in two sections the first has 8 spines and the second 1 spine and 20 to 22 soft rays. The anal fin has 2 anteriorly detached spines and 16 to 19 soft rays. The lobes of both the dorsal and anal fins are elongated. The pelvic fins contain 1 spine and 21 soft rays, while the pectoral fins are falcate and longer than the head. The lateral line has a pronounced and moderately long anterior arch, with t...Learn more about Black Jack