Bluntnose Jack, Hemicaranx amblyrhynchus
Bluntnose Jack, Hemicaranx amblyrhynchus. Fish caught off the Gulf State Park Pier, Gulf Shores, Alabama, July 2023. Length: 17 cm (6.7 inches). Catch, photograph and identification courtesy of Chris Moore, Peoria, Arizona.
The Bluntnose Jack, Hemicaranx amblyrhynchus, is a member of the Jack or Carangidae Family, and is known in Mexico as jurelito chato. Globally, there are four species in the genus Hemicaranx, all of which found in Mexican waters, two in the Atlantic and two in the Pacific Ocean.
The Bluntnose Jack has a “jack-like,” moderately compressed, elongated, and fusiform body with a depth that is 37% to 41% of standard length. They are an overall silvery color being bluish green dorsally transitioning to silvery ventrally with a transparent anal fin with a white tip, yellow caudal fin, and a dusky dorsal fin with a white tip. The juveniles have 4 or 5 bars on their sides and darker anal and dorsal fins. They have a black blotch on the gill cover. Their head is small with small eyes, a blunt snout and a terminal mouth that opens in the front. Their anal fin has 3 spines and 23 rays; their caudal fin is and forked with a longer upper lobe and a wider lower lobe; their first dorsal fin is short has 7 spines; their second dorsal fin has 3 spines and 23 to 25 rays; and their pectoral fins are longer than the head. They have 7 to 10 gill rakers on the lower arch and 18 to 23 gill rakers on the upper arch. Their body is covered with small scales. Their lateral line has a short high anterior arch with 38 to 56 strong well developed scutes.
The Bluntnose Jack is a benthopelagic species found mid-water as solitary individuals or in small schools in coastal waters at depths up to 50 m (165 feet). The juveniles are known to associate with jellyfishes. They are known to enter brackish waters. They reach a maximum of 50 cm (20 inches) in length. As of January 1, 2023, the International Game Fish Association world record stood at 0.45 kg (1 lb 0 oz) with the fish caught from coastal waters off Florida, January 2022. They are opportunistic predators and feed on benthic and pelagic fish as well as squid and crustaceans. Their eggs are pelagic. The Bluntnose Jack is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.
The Bluntnose Jack is a resident of all Mexican waters of the Atlantic Ocean but are uncommon in the Gulf of Mexico.
The Bluntnose Jack can be confused with the Atlantic Bumper, Chloroscombrus chrysurus (dark spot on top of the caudal peduncle) and the Crevalle Jack, Caranx hippos (elongated anterior rays; black pectoral fin base).
From a conservation perspective the Bluntnose Jack is currently considered to be of Least Concern with stable, widely distributed populations. They are of minor commercial importance and utilized as a human food.