Pacific Bonito, Sarda chiliensis

Pacific Bonito, Sarda chiliensis. Fish caught from coastal waters off Puerto Los Cabos, Baja California Sur, February 2004. Length: 40 cm (16 inches).

Pacific Bonito, Sarda chiliensis. Fish caught in coastal waters off  Puerto Adolfo Lopez Mateos, Baja California Sur, May 2017.  Length: 40 cm (16 inches). Catch courtesy of Jimmy Camacho, Puerto Adolfo Lopez Mateos, Baja California Sur.

Pacific Bonito, Sarda chiliensis. Fish caught from coastal waters off Long Beach, California, May 2016. Length: 42 cm (17 inches). Catch, photograph, and identification courtesy of Chris Wheaton, Fullerton, California.

Pacific Bonito, Sarda chiliensis. Fish caught from coastal waters off Long Beach, California, May 2016. Length: 44 cm (18 inches). Note the strong vertical barring pattern indicating that this fish was either in a feeding or breeding mode. Catch, photograph, and identification courtesy of Chris Wheaton, Fullerton, California.

Pacific Bonito, Sarda chiliensis. Fish caught off the Golden Reef, 22 miles east of Puertecitos, Baja California, June 2017. Length: 46 cm (18 inches). Catch, photograph, and identification courtesy of Chris Wheaton, Fullerton, California.  This is  a significant range extension for Sarda chilensis into the Northern Sea of Cortez.

Pacific Bonito, Sarda chiliensis. Fish caught from coastal waters off Tijuana, Baja California, August 2019. Length: 46 cm (18 inches). Catch, photograph, and identification courtesy of Kenneth Tse, Toronto, Canada.

The Pacific Bonito, Sarda chiliensis, is a member of the Mackerel or Scombridae Family, that is also known as the Eastern Pacific Bonito and in Mexican waters as bonito del Pacífico. Globally, there are four species in the genus Sarda, of which three are found in Mexican waters, one in the Atlantic and two in the Pacific Ocean. The fish found in Mexican waters of the Pacific is the subspecies Sarda chiliensis lineolata.

The Pacific Bonito has an elongated rounded fusiform tuna-like body that are designed aerodynamically for speed. They are silvery with a dark blue-gray back (being darker on the head), silvery flanks and belly, and a series of 5 or 6 stripes running diagonally along their upper back. Their anal and pelvic fins are white; their caudal fin is gray and deeply forked with two small keels separated by one large keel at the base; and their pectoral fins are gray. They have a moderately large mouth equipped with large prominent teeth. Their anal fin has 12 to 15 rays and 6 or 7 finlets; their caudal fin is forked; their first dorsal fin has 17 to 19 rays; their second dorsal fin has 12 to 15 rays and 7 or 8 finlets. They have 8 gill rakers on the upper arch and 15 to 18 gill rakers on the lower arch. The front of their body is covered with large scales.

The Pacific Bonito is a coastal pelagic schooling species found from the surface to depths of up to 100 m (360 feet). They reach a maximum of 1.22 m (4 feet 0 inches) in length and 11.3 kg (25 lbs) in weight. As of January 1, 2024, the International Game Fish Association world record stood at 77 cm (2 feet 6 inches), with the fish caught in off Newport Beach, California in July 2015. They are normally found within 32 km (20 miles) from shore. Young reside around sandy beaches and kelp beds while adults are found in deeper waters. They undergo extensive summer migrations of up to 1,000 km to cooler waters which mirrors the migration of their favorite prey, the Northern Anchovy. They form large schools by size. They feed primarily on Northern Anchovy and other small forage fish, amphipodes, euphausiids, squid and other crustaceans. They are rapid growing and short lived fish that can reach 51 cm (20 inches) in length within 1 year. Reproduction is oviparous with each female attaining sexual maturity at 2 years of age and then spawning several times per year by releasing about 500,000 eggs per annum. Fecundity increases exponentially with size. The eggs and larvae are pelagic. They have a lifespan of less than six years. The Pacific Bonito  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 Pacific Bonito is a resident of Mexican waters of the Pacific Ocean but has a limited distribution being found along the entire West Coast of the Baja and in the extreme southern portions of the Sea of Cortez, however, they will virtually disappear from southern portions of their range when water temperatures are elevated. A fish recently caught caught off the Golden Reef, 22 miles east of Puertecitos, Baja California in June 2017 by Chris Wheaton significantly extends the range of this species into the Northern Sea of Cortez.

The Pacific Bonito can be confused with the Black Skipjack, Euthynnus lineatus (5 or 6 horizontal stripes along upper sides; distinguishing black spots on throat); the Skipjack Tuna, Katsuwonus pelamis (4 to 6 horizontal diagonal stripes along upper sides), and the Striped Bonito, Sarda orientalis (8 to 11 broken horizontal stripes along sides; prominent teeth).

From a conservation perspective the Pacific Bonito is currently considered to be of Least Concern with stable, widely distributed populations. It is noteworthy that their populations have significantly decreased over the last ten years. They have historically been a heavily targeted commercial species but due to a significant reduction in their population fishing pressure has decreased and they are no longer targeted and have become an incidental commercial catch unless they show up in very large schools. Historically they were harvested in purse seines at levels up to 4,600,000 fish and 17,000 tons annually. They are considered an excellent food fish and sold fresh and frozen. Due to their size, coastal habitats, and horrific fights when hooked, they are also a favorite target of recreational sports anglers along the northwest coast of Baja being caught from boats, piers, jetties, and shores. They are normally caught on live sardines, rapidly trolled feathers, or hoochies, or off the bottom with chrome yo-yo irons. In California they are heavily regulated with length and bag limits.