Atlantic Bonito

Atlantic Bonito, Sarda sarda

The Atlantic Bonito, Sarda sarda, whose common Spanish name is bonito del Atlántico, is a member of the Mackerel or Scombridae Family, known collectively as macarelas in Mexico. This fish is also known as the Common Bonito. Globally, there are only four species in the genus Sarda, three of which are found in Mexican waters, one in the Atlantic and two in the Pacific.

The Atlantic Bonitos have elongated, rounded, fusiform, thick, stout, and tuna-like bodies with a depth that is approximately 25% of standard length; they are designed aerodynamically for speed. They are steely blue dorsally transitioning to silver ventrally with 5 to 11 narrow dark blue bands running slightly obliquely downward and forward across their lateral line. Their anal and pelvic fins are white; their caudal fin is dark gray; their dorsal fins are dusky with the second fin having a white tip; and their pectoral fins are gray. Their head has a moderately large mouth that ends at the rear margin of the eyes and is equipped with prominent large conical teeth. Their anal fin has a short base, is deeply concave, and has 14 to 17 rays followed by seven finlets. Their caudal fin is lunate, is much broader than long, and has one large and two small keels on its base. Their first dorsal fin has 20 to 23 spines and their second dorsal fin, which is deeply concave and closely follows the first dorsal fin, has 15 to 18 rays followed by eight finlets. Their pectoral and pelvic fins are similarly shaped and small in stature. They have 16 to 23 gill rakers on their first arch. Their lateral line is prominent and wavy and they are covered with minute scales.

The Atlantic Bonitos are common inhabitants of shallow waters being epipelagic and neritic; they are normally found at depths up to 660 feet, however, they may also enter estuaries. They reach a maximum length of 1.02 meters (3 feet 4 inches) and weight of 11 kg (24 pounds). They are typically found in waters between 12oC (54oF) and 27oC (81oF). At sea they form large schools and jump out of the water in pursuit of prey. They prey on small schooling fish and invertebrates including shrimp and squid; they are also known to be cannibalistic. Reproduction is oviparous and involves pelagic eggs and larvae. They have a lifespan of up to five years. They are a poorly studied species and very little is known about their behavioral patterns.

In Mexican waters the Atlantic Bonitos are found in all waters of the Atlantic with the exception of along the east coast of the Yucatán.

The Atlantic Bonito can be confused with the Skipjack Tuna, Katsuwonus pelamis (four to six dark horizontal stripes on belly) and the Striped Bonito, Sarda orientalis (horizontal stripes; mouth more than half the head length).

The Atlantic Bonitos are caught commercially with various types of nets, by hook and line, and as a by-catch of tuna fishermen trolling for bigger game. On a global basis they are caught at a level of 80,000 tons per annum of which 5% is taken from Mexican waters. They are a significant recreational angler foe and known for their strength and endurance. They are also used as bait. They are considered a quality food and sold fresh, dried, salted, smoked, canned, and frozen but are considered inferior to tuna. Note: canned Bonito del Norte is actually Albacore Tuna. They are reported to contain Cigua Toxin. From a conservation perspective they are widespread and fast growing, thus currently considered of Least Concern.

Atlantic Bonito, Sarda sarda. Fish caught from coastal waters off Point Pleasant, New Jersey, September 2014. Length: 56 cm (22 inches). Weight: 1.4 kg (3.1 pounds). Catch, photo, and identification courtesy of Kenneth Tse, Toronto, Canada.