Jack Fish Facts | Kidadl


Jack Fish Facts

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The crevalle jack is one of the most popular fish in the jack fish family. They are members of the Carangidae family of fish and have been found in both offshore and coastal areas. They can be found in large numbers in the eastern and western Atlantic Oceans, as well as off the coast of Florida.

There are different types of jack fish in the world. Even though the most common one is the crevalle jack, also known as trevally jack fish, other species include the yellow jack fish, amber jack fish (also known as yellowtail jack fish), blue runner or the hardtail jack, leather jack, black jack fish, white trevally (also known as striped jack fish), mangrove jack fish (also known as the mangrove red snapper), bluefin trevally, commonly known as jack fish Hawaii, and many more. The habitats of these fish are very extensive. The jack fish is not to be confused with tuna, which is a mackerel.

Read on for more interesting facts about the jack fish!

If you like this article on jacks, check out our other articles on yellowfin tuna and albacore tuna.‍

Jack Fish Facts

What do they prey on?

Prawns, shrimps, small invertebrates, mollusks, crustaceans

What do they eat?


Average litter size?

1,000,000 eggs

How much do they weigh?

70.5 lb (32 kg)

How long are they?

12-30 in (30.5-76.2 cm)

How tall are they?


What do they look like?

Silver, bluish-black, green, golden

Skin Type


What were their main threats?

Humans, Sharks, Large Fish, Seabirds, Billfish

What is their conservation status?

Least Concern

Where you'll find them?

Estuaries, Ocean, Coastal Waters, Brackish Water, Gulf, Lagoon


Pacific Ocean, Mediterranean Sea, Gulf Of Mexico









Jack Fish Interesting Facts

What type of animal is a jack fish?

The animal jack fish typically refers to crevalle jacks. It may also refer to fish like pompano and trevally.

What class of animal does a jack fish belong to?

Jack fish belong to the class Actinopterygii and the family Carangidae.

How many jack fish are there in the world?

The family of jacks includes several different species of fish under its belt. The exact number of fish is not listed.

Where does a jack fish live?

These fish live in the ocean or coastal waters, which are either tropical or temperate in nature. Their habitats also include freshwater bodies, estuaries, brackish waters, lagoons, and bays.

What is a jack fish's habitat?

The crevalle jack's habitat distribution spreads throughout the western Atlantic and eastern Atlantic regions, which ranges from Canada's Nova Scotia to Uruguay in the western Atlantic and Portugal to Angola in the eastern Atlantic Ocean. They are also found in the Mediterranean Sea, the Pacific Ocean, and the Gulf of Mexico.

Who do jack fish live with?

Jack crevalle lives in a group called the school where more than 1,000 fish can be found. However, during the time of spawning, the pairs of crevalle jacks leave the main schools temporarily only to join the group later after the spawning process is complete.

How long does a jack fish live?

The oldest jack fish studied was 17 years old.

How do they reproduce?

Crevalle jacks (Caranx hippos) reproduce by a process called spawning. In this process, the female fish lay eggs in the water during the spawning season, and the males come and fertilize it.  Female jacks can lay over a million eggs. During the process, the jack crevalle often becomes a darker shade.

The males reach sexual maturity at four or five years of age, whereas the females become sexually mature at five or six years. They reproduce all year round, although, in certain places, the peak spawning seasons vary. The adults keep the eggs and the larvae in the pelagic zone, and the small fish stay there until they become juveniles. At the juvenile stage, they swim to estuaries and lagoons, and later, when they become adults, they form schools and reside in deep waters.

What is their conservation status?

Crevalle jack is found in abundance in the Atlantic water. According to IUCN, the conservation status for the fish comes the under Least Concern category.

Jack Fish Fun Facts

What do jack fish look like?

Fishing the jacks is a common recreational and fun sport all over the world.

Crevalle jack has a silver-colored body that is oblong in shape. They also have scales around their pelvic fins. Their anal fin consists of 16-17 soft rays and one spine, whereas their dorsal fin rays have 19-21 soft rays and nine spines. The front portion of the anal fin for adults is white in color, whereas the rest of the fin can be in the shades of gray and brown. Their eyes are covered by adipose eyelids. They also have a black spot on the pectoral fins. 

Crevalle jack can range from green to bluish-black in the dorsal region and silvery or golden in the ventral region. The juveniles have five black stripes on their bodies which disappear when they become adults. The fish also has stronger canines in the upper jaw, behind which there is another layer of smaller teeth. In the lower jaw, there is only one row of teeth. The structure and arrangement of teeth assist these carnivorous fish in hunting prey.

How cute are they?

The diverse color range of the crevalle jacks makes them attractive to look at. The black spot on the pectoral fins and the small patch of scales near the pelvic region near the fins sets them apart from the others.

How do they communicate?

The jacks mostly communicate with each other in a silent process using gesture and motion.

How big is a jack fish?

The average size of a jack is 12-30 in (30.5-76.2 cm). They are a little more than double the size of a wild goldfish. In the jack family, the females are usually bigger than the males.

How fast can a jack fish swim?

The crevalle jacks can swim at the speed of 10.1 mph (16.2 kph) for 30 seconds.

How much does a jack fish weigh?

On average, freshwater jack crevalle fish and saltwater jack fish can weigh around 70.5 lb (32 kg).

What are their male and female names of the species?

There are no special names attributed to the respective sexes of this fish.

What would you call a baby jack fish?

Baby jacks are called spawns.

What do they eat?

The diet of the freshwater jack fish species mainly consists of fish. They are also known to eat a lot of shrimps, crabs, and small invertebrates. The younger crevalle jack's diet consists of small fish, whereas the adults are also seen to prey on larger fish.

Are they eaten by humans?

Jack fish, which is edible for humans, is considered not to be very appetizing. However, if cooked with proper technique, the fish can turn out to be quite wholesome and delicious. Seasoned, crispy, and golden brown fried jack fingers are one of the best delicacies made from this fish.

Would they make a good pet?

The crevalle jack fish is an aggressive predator and can be quite difficult for a fish breeder to keep them with other smaller fish. Also, this species needs a spawning ground which is normally in shallow water, making it difficult for them to be house pets as they prefer going back to the deep ocean waters when they are adults. The crevalle jack is also known to live in schools. So, separating them from their lifestyle may lower the chances of their survival.

Did you know...

Since they are both, available in offshore and coastal areas extensively, the jacks' species is commercially fishable all year. This species is also common for recreational fishing and sport.

Species of jack fish are also known to use man-made structures such as oil rig platforms as a reef for hunting prey.

Forming schools is a way that the jack fish protects itself from predators.

The northern pike (jack fish) is different from jack fish; the former is a different species of fish and belongs to a separate genus (Esox) and family (Esocidae).

One of the best techniques to catch jack fish is by using live baitfish.

What sounds do jack fish make?

Frightened crevalle jack fishes are known to produce a grunting sound when captured. They are able to emit these sounds by grinding their teeth together and creating a resonance with the air bladder.

What is the record for a jack fish?

In Florida, the fishing record for the crevalle jack is 51 lb (23.1 kg).

Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover! Learn more about some other fish including the red ear sunfish and the electric blue jack Dempsey.

You can even occupy yourself at home by drawing one of our Jack fish coloring pages.

Written By
Moumita Dutta

Moumita is a multilingual content writer and editor. She has a PostGraduate Diploma in sports management, which enhanced her sports journalism skills, as well as a degree in journalism and mass communication. She's good at writing about sports and sporting heroes. Moumita has worked with many soccer teams and produced match reports, and sports is her primary passion.

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