The Pacific crevalle jack belongs to the genus Caranx, which is part of the Carangidae family within the order Carangiformes. It is a member of the Caranx hippos species complex, alongside the Crevalle jack (Caranx hippos) and the Longfin crevalle jack (Caranx fischeri). Initially described by the British zoologist Albert Günther in 1867, the Pacific crevalle jack was named Caranx caninus, derived from the specific epithet meaning 'dog-like'. While there have been debates regarding its taxonomic classification and potential conspecificity with the Atlantic crevalle jack (Caranx hippos), the most recent review by Smith-Vaniz and Carpenter established it as a separate species based on distinct anatomical features and fin coloring.
The Pacific crevalle jack is predominantly found in the tropical to subtropical waters of the eastern Pacific Ocean. Its range stretches from California in the north to Peru in the south, encompassing various offshore islands such as the Galápagos, Malpelo, Cocos, and Revillagigedo Islands. While it is more common in coastal regions, the species can also venture into pelagic settings, although it does not inhabit depths beyond 350 meters. Sandy and rocky substrates, protected bays, lagoons, and estuaries serve as preferred habitats for the Pacific crevalle jack. Juveniles display a particular affinity for estuarine environments, showcasing their adaptability to different salinity levels.
The Pacific crevalle jack boasts a robust physique, with recorded lengths of up to 101.6 cm and weights of 19.7 kg. Its body shape resembles other members of the Caranx genus, featuring a moderately deep and compressed, oblong structure. The dorsal fin consists of eight spines in the first section and one spine with 19 to 21 soft rays in the second section. The anal fin comprises two detached spines in the anterior region, followed by one spine and 16 to 17 soft rays. Falcate pectoral fins, a strongly forked caudal fin, and a moderately arched lateral line further characterize this species. Notably, the Pacific crevalle jack possesses mostly unscaled breasts, except for a small patch of scales in front of the pelvic fins. Its coloration varies from bluish-green to bluish-black dorsally, transitioning to a silvery white or golden shade ventrally. Distinctive markings include five dark vertical bars on the sides, white or brownish-orange anal and lower caudal fins, and a black spot on the base of the pectoral fins.
Schooling behavior is prominent among Pacific crevalle jacks, especially during their early life stages. These schools range in size and exhibit rapid movement patterns. As they mature, older individuals tend to become more solitary and venture into deeper offshore waters. Ecologically, the Pacific crevalle jack holds great significance as one of the most abundant pelagic species within its range. Its diet primarily consists of small fish, crustaceans, and various benthic invertebrates, although specific data on its feeding habits remain limited.
Sexual maturity is typically attained at lengths of 67 cm for males and 65 cm for females, with spawning believed to occur throughout the year. While spawning peaks vary across regions, reported periods include January–February and August in Colombia, as well as May and November in Mexico. Pelagic eggs and larvae mark the early stages of the Pacific crevalle jack's life cycle. Growth studies have revealed different growth rates across years, influenced by factors such as seasonal variations and spawning peaks. The species exhibits both slow and fast growth periods, with faster growth occurring from August to February due to increased runoff and nutrients during the rainy season. Estimated lifespans range from 12 to 37 years, based on von Bertalanffy growth equations derived from otoliths.
The Pacific crevalle jack holds substantial importance in commercial fisheries, particularly in regions like Colima, Mexico, where it contributes up to 15% of the annual catch. Its abundance and popularity also make it a highly sought-after gamefish. Anglers target this species using various techniques, including bait fishing and employing a diverse array of lures. However, it is worth noting that the Pacific crevalle jack is considered relatively poor in quality as a food source.