Fish

Gar

Lepisosteidae · also called garfish, garpike

Not Evaluated carnivore Rivers & wetlands Coasts & shorelines

A gar is a fish from an older world. Its body is a rigid tube of enamelled armour, its jaws are a beak lined with needles, and its swim bladder doubles as a lung so it can breathe air in water that would suffocate anything else. The design is more than 100 million years old and has barely been touched since.

Overview

Gars are the family Lepisosteidae, just seven species, in the fresh and brackish waters of North and Central America and Cuba. They are long, cylindrical ambush predators with a bony beak, and they range from the metre-long shortnose gar to the alligator gar at around 3 m and 130 kg, one of the largest freshwater fish in North America. All eat mainly other fish, striking sideways with a fast snap of the jaws.

Armour and air

A gar is sheathed in ganoid scales — hard rhombic plates coated in an enamel-like layer, locked into a near-impenetrable jacket that some Native American peoples used as arrow-proof armour. Its swim bladder works as a lung: the gar gulps air at the surface, which lets it live in warm, stagnant, oxygen-poor swamps and backwaters.

A living fossil

Gars keep ancient features most modern fish have lost — the ganoid scales, a tail with the backbone running into the upper lobe, a shark-like spiral-valve gut. Their eggs are toxic to eat, protecting the clutch, though the adult flesh is edible and eaten in the American South and Mexico, once the armour is cut off with snips or a saw.

Status

Gars as a family are Not Evaluated. The smaller gars — longnose, shortnose, spotted — remain common, but the alligator gar has been lost from much of its former northern range to habitat loss, dams that block access to floodplain spawning, and decades of deliberate eradication, and is now the focus of restoration and stocking programmes.

Gar: common questions

Are gar dangerous to people?

Not really. Gars are large, armoured, and full of teeth, and a big alligator gar is an imposing animal, but there is no reliable record of a gar attacking a person in the water. They are ambush predators of fish and show no interest in humans. The realistic risks are all to do with handling a caught fish — the long jaws and needle teeth can inflict a bad cut, the sharp-edged ganoid scales can slice a hand, and a thrashing large gar is powerful. Anglers use heavy gloves and keep clear of the head. Gar eggs are toxic to eat, but the fish does not deliver any venom.

How can a gar breathe air?

A gar's swim bladder is not a simple sealed float as in most fish, but a lung-like organ connected to the gut by a tube and lined with a dense network of blood vessels and pockets that increase its surface area. The fish comes to the surface, gulps a mouthful of air into this organ, and absorbs oxygen from it directly into the blood, then releases the stale air. Gars still use their gills, but the air-breathing lets them live in warm, still, oxygen-poor backwaters, swamps, and drying pools where other predatory fish cannot, and it means a gar can be kept alive out of water for surprisingly long if its skin and gills are kept wet.

Why do people say gar are living fossils?

Because the gar body plan is ancient and has changed very little. Fossil gars from more than 100 million years ago, in the age of dinosaurs, are clearly recognisable as gars, and living gars retain a suite of primitive features that most modern bony fish have lost, among them thick, enamel-coated ganoid scales rather than thin overlapping ones, a tail in which the backbone turns up into the upper fin lobe, a spiral valve intestine like that of a shark, and the air-breathing gas bladder. Gars are not literally unchanged, and they are not the ancestors of other fish, but they are a slow-evolving lineage that offers a window onto an older kind of fish.

Are gar good to eat?

The flesh is edible and is eaten in parts of the American South, Texas, and Mexico, where gar balls, fried gar, and gar in tacos are traditional, and the meat is firm and mild, often compared to alligator or chicken. Preparing a gar is hard work, because the armour of ganoid scales cannot be removed with an ordinary knife and is usually cut with tin snips, a hatchet, or a saw. The one firm rule is that the eggs, or roe, must never be eaten, as they contain a toxin that causes severe illness in humans and is thought to be an anti-predator defence for the clutch.

Sources & further reading

Written by HideShark Editorial Team · reviewed by HideShark Science Desk. Published September 10, 2026. Last updated September 10, 2026.

Quick facts

Scientific name: Lepisosteidae
Diet: Almost entirely fish, hunted by drifting alongside a school like a floating log and then striking sideways with a fast snap of the toothed jaws, with the largest species, the alligator gar, also taking waterfowl, turtles, small mammals, and carrion
Armour of interlocking enamelled scales: A gar is covered in ganoid scales, hard rhombic plates coated in an enamel-like layer and locked together into a rigid, almost impenetrable jacket, so tough that some Native American peoples used gar skin as arrow-proof armour and covered ploughshares with it
A living fossil: Gars appeared more than 100 million years ago and have changed remarkably little since, keeping ancient features such as the ganoid scales, an asymmetrical tail with a backbone that extends into the upper lobe, and a spiral valve in the gut, all rare among modern fish
They breathe air: A gar's swim bladder is connected to the throat and richly supplied with blood vessels, so it works as a lung, and gars regularly rise to gulp air at the surface, which lets them survive in warm, stagnant, low-oxygen water that would kill most fish and even stay alive out of water for a time if kept moist
The alligator gar is a giant: The alligator gar of the southern United States and Mexico is the largest gar and one of the largest freshwater fish in North America, reaching around 3 m and over 130 kg, with a broad snout and a double row of large teeth in the upper jaw
Toxic eggs: Gar eggs contain a toxin that makes them poisonous to eat for humans and for many potential predators such as crayfish, birds, and other fish, which protects the clutch, though the flesh of the adult fish is edible and eaten in parts of the southern United States and Mexico
From trash fish to prized quarry: Gars were long dismissed as worthless predators and were culled in large numbers, but they are now recognised as native apex predators important to river ecosystems, and the alligator gar in particular has become a sought-after catch-and-release sport fish
Range: North and Central America and Cuba, in fresh and brackish water including large rivers, oxbow lakes, reservoirs, bayous, swamps, and coastal estuaries and bays, favouring warm, slow, weedy water, with the alligator gar historically ranging up the Mississippi system as far as the Ohio and Missouri rivers.
Conservation status: Not Evaluated ≈ Not assessed as a family of seven species, and the smaller gars such as the longnose, shortnose, and spotted gars remain common across their ranges, but the alligator gar has been lost from much of its former northern range through habitat loss, dams that block spawning access to floodplains, and decades of deliberate eradication, and it is now the focus of restoration and stocking programmes in several states, while the tropical gar and Cuban gar have more limited ranges in the wild