Science & Nature • Fish

Gar

Gars are an ancient group of ray-finned fishes in the family Lepisosteidae, with seven living species in two genera, Atractosteus and Lepisosteus.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 26, 2026|2 min read| Fact-checked

Gars are an ancient group of ray-finned fishes in the family Lepisosteidae, with seven living species in two genera, Atractosteus and Lepisosteus. They are native mainly to North and Central America and are known for elongated jaws, ganoid scales, and an air-breathing swim bladder used in low-oxygen water.

Classification

Gars belong to the family Lepisosteidae in the order Lepisosteiformes. Modern gars are divided into seven living species across the genera Atractosteus and Lepisosteus.

Physical characteristics

Gars are recognized by their long, cylindrical bodies, elongated snouts, and sharp teeth. Their bodies are covered in ganoid scales, and they have a swim bladder that functions in air breathing.

Distribution and habitat

Gars occur mainly in North and Central America and the West Indies. They are usually associated with fresh water, though some species can enter brackish or even salt water.

Ecology and behaviour

Gars are ambush predators that feed largely on fish. They often inhabit slow-moving or vegetated waters and can tolerate low-oxygen environments better than many other fish.

Key facts

Gars are large, primitive-looking bony fishes in the family Lepisosteidae.
They are native chiefly to North and Central America, with some species reaching brackish water.
Their bodies are covered with hard ganoid scales that act like armour.
They have elongated jaws filled with sharp teeth and are ambush predators.
A lung-like swim bladder helps them survive in low-oxygen conditions by gulping air.

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Canadian context

Gars reach the southern part of Canada and are of interest to Canadian anglers, wildlife managers, and naturalists, especially in the context of native freshwater fish in the Great Lakes–St. Lawrence and prairie drainages.

Frequently asked questions

How many species of gar are there?

There are seven living species of gar in two genera, Atractosteus and Lepisosteus.

Where do gars live?

Gars are found mainly in North and Central America and the West Indies, usually in fresh water, though some species use brackish water.

What do gars look like?

They have long bodies, elongated jaws, sharp teeth, and hard ganoid scales that give them an armored appearance.

How do gars survive low-oxygen water?

They have a lung-like swim bladder that lets them gulp air at the surface.

Are gars ancient fish?

Yes. They are an ancient lineage of fish and are often described as primitive because they retain several older anatomical traits.

References

Encyclopaedia Britannica — https://www.britannica.com/animal/gar
Supports: Seven species, genera Atractosteus and Lepisosteus, family Lepisosteidae, mainly freshwater distribution.
SeaWorld / United Parks & Resorts — https://seaworld.org/animals/facts/bony-fish/gars/
Supports: Family, order, body form, ganoid scales, and distribution in Central and North America and the West Indies.
Kentucky Department of Fish & Wildlife — https://fw.ky.gov/Fish/Pages/Gar-Family.aspx
Supports: Habitat, ganoid scales, ambush predation, air-breathing swim bladder, and ecological role.
U.S. Fish and Wildlife Service — https://www.fws.gov/story/all-about-alligator-gar
Supports: Seven living gar species and modern distribution extending into southern Canada and Central America.