Jack Crevalle

Quick Take

• Jack crevalles are prized fighters on the line, and what happens the moment one gets caught will genuinely surprise you. See the fighting reputation →
• Sport fishers chase them obsessively, yet most anglers won't eat one, and the reason behind this reveals a sharp divide between a fish's reputation and its reality. Explore the sport vs. food divide →
• As jack crevalles grow larger, some make a dramatic behavioral shift that sets them apart from virtually every other member of their school. Discover the schooling behavior →
• Scientists still can't fully agree on what species the jack crevalle actually is, with the debate coming down to a surprisingly subtle physical difference. Follow the species debate →

The jack crevalle is a highly predatory species of marine fish belonging to the genus Caranx. It roams freely throughout the Atlantic Ocean, appearing along the coasts of many adjacent countries. It primarily preys on smaller fish and various invertebrates like crustaceans. Although sport fishers value it as a tough game fish, it is not a popular food fish and has limited commercial value.

5 Jack Crevalle Facts

• One of the largest species in Caranx: This species is one of the largest members of the genus Caranx, weighing as much as 70 pounds and growing up to four feet long.
• Fearless predators: These fish are famous for their ferocious hunting instinct, which makes them valuable game fish.
• Diurnal: This species is diurnal, which means it is mainly active in the daytime.
• Larger individuals may leave their schools: Although most adults of this species move in schools, some choose to go off on their own once they grow large enough.
• Females grow larger than males: Females of this species tend to grow to greater lengths and weigh more than their male counterparts.

Classification and Scientific Name

The jack crevalle (Caranx hippos) is a predatory marine fish in the genus Caranx (jacks, trevallies, and pompanos), which contains 18 species. Alternate names for Caranx hippos include crevalle jack, common jack, black-tailed trevally, couvalli jack, black cavalli, and yellow cavalli.

From a broader taxonomic perspective, the jack crevalle is a ray-finned fish (class Actinopterygii) in the order Carangiformes (jacks). It further belongs to the family Carangidae (jacks and pompanos). Carangidae contains 32 genera and over 150 species.

Appearance

The broad-bodied jack crevalle is among the largest members of its genus. It grows up to four feet in length, though a mature length of one to 2.5 feet is more common. While adults of this species can weigh as little as two pounds, the heaviest specimen on record weighed 70.55 pounds. Females generally grow larger than males.

This species’ distinguishing marks include a steep forehead and dark spots on the gill covers, bases of the pectoral fins, and possibly the lower pectoral rays. The dorsal region ranges from olive to bluish-green in color with brassy or silvery sides. Although scales are present on most of the body, they are absent from the chest and throat.

Distribution, Population, and Habitat

The jack crevalle is common in both the eastern and western Atlantic Ocean and also the western Mediterranean. Although there are reports of these fish in the Pacific Ocean, these sightings most likely refer to a related species, the Pacific crevalle jack (Caranx caninus). Similarly, reports of the species in the Indian Ocean are probably sightings of the giant trevally (Caranx ignobilis).

The jack crevalle inhabits waters along the coasts of North America, South America, Europe, and Africa, as well as Turkey in Asia. It ranges from Nova Scotia in Canada as far as Uruguay in South America, including the following U.S. states: New Jersey, Delaware, Maryland, Virginia, North Carolina, South Carolina, Georgia, Florida, Alabama, Mississippi, Louisiana, and Texas.

This species primarily lives in marine environments, though it occasionally enters brackish waters. It is reef-associated and oceanodromous (migratory within salt waters), swimming at depths up to 1,150 feet.

Worldwide populations of this species are currently stable. As of 2018, the IUCN lists the species as Least Concern.

Evolution and History

Within the Paleogene Period, the Eocene Epoch (56 to 33.9 million years ago) was a time of emergence for many of today’s perciforms, including members of Caranx. The first fossils from this genus came from the mid-Eocene. As with many fish species, otoliths (ear bones) are the most common type of fossil for Caranx.

Linnaeus first described the jack crevalle in 1766. Its initial scientific name was Scomber hippos. This later became Caranx hippos after naturalist Bernard Germain de Lacépède created the genus Caranx. The species was known by a variety of names throughout its history, including Caranx carangua and Caranx hippos caninus, which have since fallen out of favor.

Scientists have debated whether or not to consider the jack crevalle (Caranx hippos) the same species as the Pacific crevalle jack (Caranx caninus) from the eastern Pacific. This debate also extends to a relatively new species, the longfin crevalle jack (Caranx fischeri) from the eastern Atlantic. These three species are part of the crevalle jack complex and are morphologically similar with dark marks on their pectoral fins and opercules, similar scale patterns on their breasts, and enlarged canines in their lower jaws. However, the consensus is that these remain separate species due in part to variations in hyperostosis and anal fin colors.

Predators and Prey

Jack crevalles are highly predatory carnivores that do most of their hunting in the daytime. However, their frequent proximity to the surface makes them vulnerable to certain other predators.

What Do Jack Crevalle Eat?

These fish prey mostly on smaller fish like mackerel, mullet, anchovies, and pinfish. They also eat invertebrates like crustaceans (including shrimps, prawns, and crabs) and mollusks (including some cephalopods like squid). Juveniles mainly eat small fish and crustaceans.

What Eats Jack Crevalle?

Despite being fearless predators, these fish frequently fall prey to other marine fish like sharks, marlins, and barracudas. Juveniles are the targets of any fish larger than themselves, as well as hunting seabirds, which pick them off near the surface of the water.

Reproduction and Lifespan

The jack crevalle is iteroparous, reproducing several times throughout its life. It is also oviparous, laying eggs that hatch outside its body. Spawning usually occurs year-round, with specific peak periods in some regions. For example, the typical spawning period in Florida is early March to early September. In Ghana, however, peak spawning occurs between October and January.

Before spawning, these fish form large schools and either move offshore or inshore to bays and reefs. Sexually mature pairs break off from the main school, whereupon the female lays her eggs. The male then fertilizes them. The eggs are pelagic, remaining in open water until they hatch. The larvae stay in the same area until they reach the juvenile stage. At this point, they head to brackish estuaries or lagoons. They return to the ocean when they are sufficiently mature. Although larger individuals may be solitary, most adults remain in fast-moving schools.

Males attain sexual maturity between four and five years old, while females become mature at five or six years old. Females may produce as many as one million eggs. Additionally, fish of this species can live as long as 19 years.

Fishing and Cooking

The jack crevalle is a popular game fish for its size and fighting spirit. When caught, these fish may emit croaking or grunting noises. They tend to bite hard and fight even harder, so anglers should be prepared for a struggle when reeling one in. Both live bait and artificial lures have proven successful.

Despite its popularity among sport fishers, this species does not make the best food fish. It tends to be strongly flavored and oily and is best suited for bait. However, it is still edible and can make a decent meal if carefully prepared. Check out this article for advice on how to prepare and cook jack crevalle.