Home   —

Alligator Gar

The alligator gar (Atractosteus spatula) is a ray-finned euryhaline fish related to the bowfin. It is the largest species in the gar family, and among the largest freshwater fish in North America. The fossil record traces its group’s existence back to the Early Cretaceous over 100 million years ago. Gars are often referred to as “living fossils” because they have retained some morphological characteristics of their early ancestors, such as a spiral valve intestine, and the ability to breathe both air and water. Their common name was derived from their resemblance to the American alligator. An alligator gar can grow up to 10 ft (3.0 m) in length.


Their body is torpedo-shaped, usually brown or olive, fading to a lighter gray or yellow ventral surface. In very rare occurrences, they can also be black, seen in gars that have a high level of melanin. Their scales are not like the scales of other fishes; rather, they are ganoid scales, which are bone-like, rhomboidal-shaped scales, often with serrated edges, and covered by an enamel-like substance. Ganoid scales are nearly impenetrable and are excellent protection against predation. Unlike other gar species, the upper jaw of an alligator gar has a dual row of large, sharp teeth that are used to impale and hold prey. Alligator gar are stalking, ambush predators, they also ambush and eat waterfowl and small mammals they find floating on the water’s surface.

Population, and Habitat

Theey can be found in the lakes, rivers, estuaries, bayous, and reservoirs of the Southern United States and Eastern Mexico. Its range once extended as far north as Iowa and Nebraska, but after years of hunting, the alligator gar now mostly occupies the lower Mississippi River Valley and possibly as far south as Veracruz, Mexico. The gar’s bladder functions as a kind of lung that enables it to survive in water with low oxygen content. It also has the ability to tolerate a bit of salt water, but it never ventures out to the open sea.

Alligator gar is considered a species of least concern by the IUCN Red List. Populations of alligator gar have been extirpated from much of their historic range as a result of habitat destruction, indiscriminate culling, and unrestricted harvests. Populations are now located primarily in the southern portions of the United States extending into Mexico. They are considered euryhaline because they can adapt to varying salinities ranging from freshwater lakes and swamps to brackish marshes, estuaries, and bays along the Gulf of Mexico.

Predators and Prey

The alligator gar is one of the top predators in its natural freshwater environment.  It is an ambush predator that lies in wait for prey and then attacks with its large jaws. The gar’s good vision and ability to sense chemicals seem to be the main means by which they detect prey in the water. They play a similar role as sharks in marine ecosystems by keeping prey populations within healthy numbers.

What does the alligator gar eat?
The alligator gar preys upon almost anything that will fit into its mouth, including smaller fish, turtles, birds, and even small mammals. Some of their favorite fish include buffalo fish, carp, and shad.

What eats the alligator gar?
A fully grown alligator gar has few predators in the wild except for humans and actual alligators. The juveniles are sometimes preyed upon by other fish as well.

Feeding behavior

Alligator gar are relatively passive, seemingly sluggish solitary fish, but voracious ambush predators. They are opportunistic night predators and are primarily piscivores, but they also ambush and eat water fowl, turtles, and small mammals that may be floating on the surface. Their method of ambush is to float a few feet below the surface, and wait for unsuspecting prey to swim within reach. They lunge forward, and with a sweeping motion, grab their prey, impaling it on their double rows of sharp teeth.

Diet studies have shown alligator gar to be opportunistic piscivores, and even scavengers depending on the availability of their preferred food source. They occasionally ingest sport fish, but the majority of stomach content studies suggest they feed predominately on forage fishes such as gizzard shad as well as invertebrates and water fowl. However, brackish water populations of alligator gar are known to feed heavily on blue crabs in addition to fish such as the hardhead catfish (Ariopsis felis). Diet studies have also revealed fishing tackle and boat-engine parts in their stomachs.

Alligator Gar Reproduction and Lifespan

The breeding season occurs between May and July. In Texas, at least, the female does not reproduce every year. Instead, she tends to reproduce when water overruns the banks and creates floodplains. This allows her to lay thousands of dark green or red eggs on the rocks and vegetation near the banks. Although they receive minimal parental care, the unborn gars have a very useful defense mechanism: their eggs are toxic to ingest.

After about six to eight days, the offspring hatch from the eggs, measuring only a small fraction of their full adult size. With their long, sinewy body, they almost resemble sticks. A disc on the snout lets them remain attached to rocks and vegetation, where they continue to grow rapidly by absorbing what’s left of the yolk sac. After the yolk is depleted, they must be ready to fend for themselves.

Since a typical lake can only support a few hundred alligator gar at most, many of the young are obviously expected to be lost to predation early on. These fish grow rapidly in its first year or two of life, though it takes about around 10 years for the alligator gar to reach sexual maturity. Some have a lifespan of more than 50 years in the wild. Females seem to live longer than males on average.

3 Alligator Jar Facts!

  1. The large front teeth and powerful jaws are adaptations to help them eat large, hard prey.
  2. Males initiate courtship by bobbing their heads up and down. This has given it the alternative name of koggelmander, or “little mocking man,” in the South African Afrikaans language.
  3. The agama’s colors will suddenly become brighter when it’s alarmed or agitated in some manner.

FAQs (Frequently Asked Questions)

Their common name was derived from their resemblance to the American alligator, particularly their broad snouts and long, sharp teeth. Anecdotal evidence suggests that an alligator gar can grow up to 10 ft (3.0 m) in length.

Texas is king, followed by Mississippi, Oklahoma, Arkansas and Florida. Estuaries along the Gulf of Mexico for coast states are prime locations. They can also be found in saltwater, usually further out. The habitat of alligator gars varies by season.

The world record for the largest alligator gar ever caught is 8 feet 5 inches and 327 pounds. Researchers estimate that fish was 95 years old. “It’s very likely there are alligator gar out there that are over 100 years old,”

Due to its large size and sharp teeth, the alligator gar is capable of delivering a serious bite wound to fisherman or swimmers. However, there is no documentation of attacks on man by alligator gars. The eggs are poisonous, causing illness if consumed by humans.

Share Post:


Related Topics

Inline Feedbacks
View all comments