June 12, 2017
Posted by: Naturalist Team
Alligator gar (Atractosteus spatula) are a true prehistoric creature that have remained a hearty predator for millions of years. They have been compared with the earliest terrestrial tetrapods which evolved from the ocean during the late Devonian period. Alligator gar are the largest species in the Gar family (Lepisosteidae), reaching up to 400 pounds and 12 feet in length! The rostrum, or mouth of an alligator gar is short and broad with two rows of extremely sharp alligator-like teeth on the upper jaw, unlike other species of gar which contain one row of teeth. These fish have an elongated body with a single dorsal and anal fin posterior near the heterocercal (rounded) caudal fin. A thick row of nonoverlapping and diamond shaped ganoid scales cover the body, acting as an armor layer to protect from predation. Alligator gar are generally dark olive-brown in color, with dark brown fins and a yellow belly. It is easy to spot gar in a body of water because they contain a lung-like gas bladder which they inflate by taking in gulps of atmospheric oxygen from the water surface! This allows them to reach various levels of the water column by inflating and burping out gas from their gas bladder.
It is common to find alligator gar in slow-moving pools and creeks extended from larger rivers, bayous, lakes, and swamps—mainly in the Mississippi Delta. Alligator gar are mainly piscivores, or consumers of fish, but also eat snakes, small mammals, turtles, and birds. Females generally lay 138,000 eggs which cling to vegetation or rocky substrate in which two or three males will fertilize simultaneously. Females can also live up to 50 years, while males only live up to 25 years old!