Alligator Snapping Turtle

Range
Native to southeast region of the United States. Confined to river systems that drain into the Gulf of Mexico. They are most prevalent from northern Florida and Georgia through the Gulf States to Texas and Oklahoma, but have been seen as far north as Indiana, Illinois, Kansas and Iowa.

Habitat
Freshwater areas, generally in deep water of large rivers, canals, swamps, and lakes.

Size
Largest freshwater turtle in the world, weighing between 154 and 176 pounds on average. The largest verified weight is 219 lbs. but there are legends with some photographic credibility of larger specimens, most famously a reported 403 lb alligator snapping turtle caught out of the Neosho River of Kansas in 1937.

Coloring
Brown or gray

Distinguishing Characteristics
The Alligator Snapping Turtle has three large, pronounced ridges that run from the front to the back of the carapace. They have powerful jaws, large heads, and are unique among snapping turtles for having eyes on the side of their heads.

Method of Temperature Regulation
Ectothermic

Diet in Zoo
Trout and herring as well as an occasional rat

Diet in Wild
Any kind of fish, but also frogs, snakes, snails, worms, clams, crayfish, aquatic plants, and other turtles

Reproduction
It is unlikely that females reproduce more than once a year, some females lay eggs on an alternate-year basis. These turtles mate in early spring in Florida and late spring in the Mississippi Valley. Females lay eggs in a nest about two months later in a nest hole dug approximately 50 m from a body of water. All nests are dug in the sand and clutch success is highly variable. A clutch may contain 8 to 52 eggs. This is the only time a female leaves the water; males generally never leaves the water.

Gestation/incubation
100 to 140 days

Offspring
Hatchlings emerge in the fall. Sexual maturity is reached by both sexes at 11 to 13 years of age. Besides the act of mating, males invest no additional time or energy towards parenting. Juvenile turtles are independent upon hatching.

Longevity
Males live from 11 to 45 years with an average age of 26 years. Females live from 15 to 37 years with an average of 23 years. Alligator snapping turtles can live a very long time in captivity; the oldest known individual was 70 years old.

Behaviors/Adaptations
Alligator Snapping Turtles look very primitive and have been called the dinosaur of the turtle world. They use chemosensory cues to locate prey items. They use gular (throat) pumping to draw water in and out to sample the surrounding water for chemicals that have been released by prey species. Adult snapping turtles use this sensory system to hunt and locate mud and musk turtles that have buried themselves into the bottom of a body of water.

Unique Behaviors

  • Can stay submerged for 40 to 50 minutes at a time
  • They actively scavenge for food at night. During the day they often lie quietly in wait to lure an unsuspecting fish by revealing a small pink worm-like lure inside their gray mouth
  • Often so motionless while lying underwater that they grow algae on their backs

Predators
The only known predators of adults are humans, but eggs and hatchlings are a source of food for large fish, raccoons, and birds.

Status
Alligator snapping turtles are threatened by human exploitation in all U.S. states, but especially in Louisiana. In 1991 the U.S. Fish and Wildlife Services (USFWS) nominated alligator snapping turtles as a candidate to be placed on the Endangered Species list, but the USFWS later concluded in 1999 that they did not warrant protection under the Endangered Species Act. In 2004 the state of Louisiana put a ban on the commercial harvest of M. temminckii anywhere in the state.