Fish and Aquatic Conservation

an artwork of an Alligator gar

Fish illustration by Laury Zicari, USFWS, Retired

Alligator gar

My Scientific Name

Atractosteus spatula

By the Numbers

I can weigh up to 350 pounds and grow 10 feet in length. Adults are generally 4 to 6 feet long and weigh 100 to 160 pounds. My International Game Fish Association World Record from the Rio Grande River in Texas weighed 279 pounds.

How to Identify Me

I have a broad or wide, short snout, and a very large body. I am dark olive-brown becoming whitish toward my belly. I am covered with ganoid scales, which are thick overlapping scales, and I have two rows of teeth on my upper jaw.

Why I Matter and What's Been Happening

People used to make arrowheads, jewelry and tools from my scales. My skin made a durable leather for many purposes, and my oils were used as an insect repellent. The construction of dams along the Mississippi River eliminated a lot of the floodplain habitat (side channels and backwater areas connected to rivers) that I need for spawning and young fish need to grow. We also were overfished because of a mistaken belief that with our toothy appearance and large size, we ate a lot of the other fish that people liked to eat. There was a major effort to get rid of us in the early 1950s.

My Status

We once were pretty abundant, but are now difficult to find. People are working together to restore more of our rivers, and raise me in hatcheries to stock me back out in our rivers.

did you know image
  • Alligator gar are euryhaline; meaning they are able to live in fresh and salty waters.
  • The Alligator gar is sometimes referred to as a “living fossil” because scientists can trace them in the fossil record back 100 million years!
  • This majestic fish is the largest of the seven species of gar found in North America, Central America, and Cuba.
  • They used to be found throughout the Mississippi River Valley from Iowa down to the Gulf of Mexico (Figure 1).
  • They live mostly in slower moving rivers, oxbows, reservoirs, and brackish estuaries along the Gulf of Mexico, but they have also been found further out in saltwater.
  • Alligator gars have gills like other fish, but they also have a swim bladder connected to their gut by a unique duct which allows them to gulp air from the surface, and live in water that is low oxygen.
  • Alligator gars can live to be 50 years old in nature.

a map of Southeastern section of the USA with black dots on it showing the historic range of Alligator gar

Figure 1 – Alligator gar historic range. Credit: Atlas of North American Freshwater Fishes.

More about Us image

two hands with light blue latex gloves on, holding a young Alligator gar

When the young Alligator gar reaches 8–10 inches they are ready to be released into streams in Mississippi and Tennessee to help promote the survival of this species.

two biologists on a fishing boat motor, pulling up a mature Alligator gar in a fishing net

These river herring were caught by biologists in the Connecticut River during annual fish surveys. The alewife (top) has a slightly larger eye than the blueback herring (bottom).

weighing adult Alligator gar

Adult Alligator gar are weighed and checked for good health prior to bringing to the hatchery for spawning and producing fish.

How you can help statement: Get to know me, if you don’t already. Help make me visible to people who don’t have the chance to see me by sharing your stories about me. Get involved in efforts to help conserve my habitat and maintain my populations into the future.