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alligator gar

alligator gar (Atractosteus spatulai) [extirpated, but transplanted]
Photo © Solomon David

Features and Behaviors


An alligator gar can grow to eight feet in length and weigh more than 300 pounds. This animal is the second largest freshwater fish species in North America. Its diet depends on the most readily available food source, usually gizzard shad (Dorosoma cepedianum), and other species not prized for sport fishing. Individuals will scavenge for dead items to supplement live prey, too. The species has two rows of teeth on the upper jaw. The snout is short, with the upper jaw shorter than the rest of the head. Young alligator gars have a light line from the tip of the snout to the base of the caudal fin. Adults are dark green-brown on the back and sides and may have spots. The belly is white to yellow. Pools and backwaters of large rivers, swamps and lakes are the habitats preferred by this species.


By the 1960s, the alligator gars were extirpated from Illinois. Huge declines in their populations occurred throughout their range in the Mississippi River basin. The U.S. Fish and Wildlife Service began a project in the late 1990s to raise and reintroduce alligator gars to their historic range. Illinois began stocking alligator gars through this program in 2010 and continues to do so in an effort to add to the biodiversity of the ecosystems where they are found.

Illinois Range


Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Lepisosteiformes
Family: Lepisosteidae

Illinois Status: ​extirpated but being restocked, native