Striped Bonito

Striped Bonito, Sarda orientalis

The Striped Bonito, Sarda orientalis, whose common Spanish name is bonito mono, is a member of the Mackerel or Scombridae Family, known collectively as macarelas in Mexico. 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 Striped Bonitos have elongated rounded fusiform tuna-like bodies that are designed aerodynamically for speed. They are dark blue-gray dorsally (darker on their head) and silvery ventrally and on their flanks. They have a series of 8 to 11 broken narrow stripes running horizontally along their upper back. Their second dorsal fin is black. They have a moderately large mouth equipped with large prominent conical teeth on both jaws. Their anal fin has 13 to 16 rays and 5 to 7 finlets. Their caudal fin is deeply forked with two small keels separated by one large keel at the base. They have two dorsal fins set close together, the first having 17 to 19 spines and the second having 14 to 16 rays followed by 7 to 9 finlets. They have small gill rakers and their body is covered with small scales.

The Striped Bonitos are a coastal pelagic schooling species often found associated with schools of small tuna. They are found from the surface to depths up to 165 meters (550 feet). They reach a maximum of 1.17 meters (3 feet 10 inches) in length and 10.7 kg (24 pounds) in weight. They form large schools and feed on fish, clupeoids, squids, and crustaceans. They are found in water temperatures between 13.5oC (56oF) and 23oC (73oF). Reproduction is oviparous with each female spawning several times per year and releasing between 80,000 and 115,000 eggs per annum. Eggs and larvae are pelagic. Very little is known about their behavioral patterns.

In Mexican waters the Striped Bonito have a limited distribution being found from Magdalena Bay southward along the southwest coast of Baja, in the southern 20% of the Sea of Cortez, and along the coast of the mainland south to Guatemala. I have a recent report from Chris Wheaton that he catches the Striped Bonito fairly regularly in coastal waters off Loreto extending the known range of this species further into the Sea of Cortez.

The Striped Bonito can be confused with the Black Skipjack, Euthynnus lineatus (distinguishing black spots on throat), the Skipjack Tuna, Katsuwonus pelamis (four to six horizontal dark stripes on sides), and most certainly the Pacific Bonito, Sarda chiliensis (five or six oblique dark stripes on upper back).

The Striped Bonitos are not fished commercially. They are caught as an incidental catch with purse seines and sold fresh, frozen, dry-salted, and canned. They are also caught by artisanal fishermen. They are considered an excellent food fish. Due to their size, coastal habitats, and horrific fights when hooked, they are also a favorite target of recreational sports anglers. From a conservation perspective they are currently considered to be of Least Concern, however, their populations are poorly documented with a wide global distribution.

Striped Bonito, Sarda orientalis. Fish caught from coastal waters off Puerto Los Cabos, Baja California Sur, May 2003. Length: 58 cm (23 inches).

Striped Bonito, Sarda orientalis. Fish caught from coastal waters off Puerto Los Cabos, Baja California Sur, January 2014. Photo of the now departed “Ramon” (a longtime good friend of within the confines of Puerto Los Cabos. Photo courtesy of Eric Brictson, Gordo Banks Pangas, La Playita, Baja California Sur.