Bullet Mackerel, Auxis rochei rochei
Bullet Mackerel, Auxis rochei rochei. Fish caught from coastal waters off Tokyo, Japan, January 2022. Length: 43 cm (17 inches). Catch, photograph and identification courtesy of Ben Cantrell, Peoria, Illinois.
The Bullet Mackerel, Auxis rochei rochei, is one of the most common members of the Mackerel or Scombridae Family, that is also known as the Bullet Mackerel, and in Mexico as barrilete melvera. Globally, there are four species in the Auxis Genus, two are found in the Atlantic Ocean and two in the Pacific Ocean.
The Bullet Mackerel has a robust elongated rounded fusiform tuna-like body. They are torpedo-shaped with no fins and are designed aerodynamically for speed. Dorsally, they are dark bluish with fifteen or more fairly broad nearly vertical bars above their lateral line; ventrally, they are silvery white. They have mid-sized black eyes and slender conical teeth. Their anal fin is small with 12 to 14 rays and 7 finlets; their caudal fin is deeply forked with 2 small keels separated by 1 large keel at the base; their first dorsal fin has 9 to 12 spines followed by 8 finlets; their second dorsal fin is widely separated from the first, and is small with 10 to 13 rays and followed by 8 finlets; and, their pectoral fins are short. The front portion of their body is covered with scales. The Bullet Mackerel are a pelagic highly migratory species found in both oceanic and coastal waters at depths up to 200 m (655 feet). They reach a maximum of 55 cm (22 inches) in length and 1.8 kg (4 lbs 0 oz) in weight. As of December 1, 2025, the International Game Fish Association world record stood at 1.84 kg (4 lbs 1 oz) with the fish caught in coastal waters off Spain in July 2004. They normally travel in large schools at times mixed in with Frigate Mackerel, Auxis thazard. Each female releases between 31,000 and 103,000 eggs annually with the eggs and larvae being pelagic. The larvae from the four species of Auxis are the most abundant of all tuna larvae. Due to their abundance they are considered an important component of the oceanic food web, particularly as food for larger fish. They feed on small fish, crustaceans, and squids. They have lifespans of five years. The Bullet Mackerel is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, diet, growth, habitat, longevity, movement patterns, and reproduction.
The Bullet Mackerel is a resident of Mexican waters of the Atlantic Ocean but is limited to the coastal waters surrounding the Yucatán Peninsula.
The Bullet Mackerel is very similar to and can be very easily be confused with the Bullet Tuna, Auxis euydorax (Pacific Ocean species) and the Frigate Mackerel, Auxis thazard (15 or more broad oblique to oblique bars beginning under the first dorsal and pectoral fins).
From a conservation perspective the Bullet Mackerel are currently considered to be of Least Concern, with stable, widely distributed populations. They are considered an important commercial catch in certain parts of the world being caught by hook and line and as a by-catch in gill nets, purse seines, and traps at a level of 250,000 tons per year. They are marketed fresh, frozen, dried and salted, and smoked and canned.