The alligator snapping turtle is a huge aquatic species with a noticeably large head (as compared to other species of turtles). The upper shell has 3 prominent ridges — 1 along the center line and 1 on either side. The large head terminates in a sharp, strongly hooked beak. The tail is long and muscular. The skin on the head, neck, and forelimbs has a number of fleshy projections or tubercles. Adults have dark brown heads, limbs, and shells; the skin on the neck and other areas may be yellowish brown.
Similar species: The snapping turtle (Chelydra serpentina) is more common and widespread in our state. Adults have a more rounded shell, lacking the 3 prominent ridges described for the alligator snapping turtle. Also, the head is often covered with numerous small black lines or spots. Underparts are yellowish-white. The upper part of the tail has large, pointy scales in a sawtoothed row. The eyes can be seen from above.
Upper shell length: 15–26 inches; weight 35–150 pounds.
Presumed to occur in the large rivers, sloughs, and oxbow lakes of southern, southeastern, and eastern Missouri.
Habitat and Conservation
Deep sloughs, oxbow lakes, and deep pools of large rivers. This species is totally aquatic and seldom climbs out of the water onto objects to bask in the sun. Most individuals seen out of water are apparently females seeking an egg-laying site. Otherwise, they spend most of their time in deep water, hiding in root snags or among submerged logs. They are most active at night and walk slowly as opposed to swimming.
Mainly fish, but also small turtles. Young alligator snappers eat a variety of small aquatic prey. This species is unique among North American turtles in having the ability to lure fish to its mouth. Its tongue has a special appendage shaped like a stout worm; it can be moved at will by the turtle while it lies motionless on the bottom of a river of slough. Fish are attracted to the wriggling “worm” and are captured and eaten when they venture too close.
Rare and declining due to water pollution, habitat loss, reduction of egg-laying sites, and overharvesting. Imperiled in Missouri, possibly vulnerable globally. Missouri and federal law prohibits the importation, transportation, sale, purchase, taking, or possession of animals on the State or Federal lists. If fishing, check your limb lines and trotlines daily; if you catch one of these rare turtles you must release it unharmed.
Individuals become sexually mature between 11 and 13 years of age. Courtship and breeding take place in water, presumably in late spring. Females emerge from the water in May and June to dig a nest and lay eggs. About 16–52 eggs may be laid by a single female. Hatching probably takes place in late summer. There is evidence that some adult females may only produce eggs every other year instead of annually.
In the past, alligator snapping turtles served humans in many ways, providing their bodies as meat and as pets, and their shells as conversation pieces. Today, their alarming decline is a call for us to serve the snappers by working to restore their numbers.
These turtles help to keep the populations of many aquatic animals in check. Meanwhile, despite the ability of adults to defend themselves, eggs and nests are very vulnerable to predators such as skunks and raccoons.