The Alligator Snapping Turtle (Macrochelys temminckii) is one of the largest freshwater turtles in the world. It is not closely related to, but is often associated with the common snapping turtle. They are the sole living member of the genus Macrochelys--while common snappers are in the genus Chelydra. The epithet temminckii is in honor of Dutch zoologistCoenraad Jacob Temminck.
The largest freshwater turtle in North America, the alligator snapping turtle is found primarily in southern United States waters. They are found from eastern Texas east to the Florida panhandle, and north to southeastern Kansas, Missouri, southeastern Iowa, western Illinois, western Kentucky, and western Tennessee. Typically only nesting females will venture onto open land.
Due to the exotic pet trade and other factors the species has found its way to Asia and Europe with a breeding/research center found in Japan.
In the UK they have also been found mainly on the end of fishing lines. People are unsure of exactly how many are breeding here but there could be as many as 10-20 for all we know. They got here from being released by pet owners once they grew to big for them to handle.
There is an unverified report of a 403-pound (183 kg) Alligator Snapping Turtle found in Kansas in 1937, but the largest one actually on record is debatable. One weighed at the Shedd Aquarium in Chicago was a 16-year resident giant alligator snapper weighing 249 lb (113 kg), sent to the Tennessee State Aquarium as part of a breeding loan in 1999. Another was 236 lb (107 kg), and housed at the Brookfield Zoo in suburban Chicago. Both of these may still be alive. They generally do not grow quite that large—average adult size is around 26 inches shell length with a weight of 175 lb (80 kg). Males are typically larger than females. Alligator snapping turtles can also range in length from 16 to 32 inches (40.4 to 80.8 cm).The alligator snapping turtle is characterized by a large, heavy head, and a long, thick shell with three dorsal ridges of large scales (osteoderms) giving it a primitive appearance reminiscent of some of the plated dinosaurs. They can be immediately distinguished from the Common Snapping Turtle by the three distinct rows of spikes and raised plates on the carapace, whereas the common snapping turtle has a smoother carapace. They are a solid gray,brown, black, or olive-green in color, and often covered with algae. They have radiating yellowpatterns around the eyes, serving to break up the outline of the eye and keep the turtle camouflaged. Their eyes are also surrounded by a star-shaped arrangement of fleshy filamentous "eyelashes."
Contrary to claims that Alligator Snapping Turtles possess the second strongest bite force of any animal, it has been recorded at 158 ±18 kilograms-force (1,550 ±180 N; 350 ±40 lbf) which is lower than several other species of turtle and at about the same level as humans. Still, these turtles must be handled with extreme care.The inside of the turtle's mouth is camouflaged, and it possesses a vermiform (literally, "worm-shaped") appendage on the tip of its tongue used to lure fish, a form of Peckhamian mimicry. The turtle hunts by lying motionless in the water with its mouth wide open. The vermiform tongue imitates the movements of a worm, luring prey to the turtle's mouth. The mouth is then closed with tremendous speed and force, completing the ambush.In mature specimens (carapace length over 12 inches) male and female can be differentiated by the position of the cloaca from the carapace and the thickness of the tail's base. A mature male's cloaca extends beyond the carapace edge, a female's is placed exactly on the edge if not nearer to the plastron. The base of the tail of the male is also thicker as compared to females because of the hidden reproductive organs.
Alligator snappers are opportunistic carnivores more often at a young age, but are also scavengers. Fishermen have glorified the species' ability to catch fish and to deplete fish populations. Minnows are usually the main source of meat for the species at a young age.They will eat almost anything they can catch.
Their natural diet consists primarily of fish and dead fish carcasses (usually thrown overboard by fishermen), invertebrates, carrion, and amphibians, but they are also known to eat snakes, and even other turtles. In captivity they may consume almost any kind of meat provided, including beef, chicken and pork although these are not always healthy on a day to day basis. They will refuse to eat if exposed to temperature extremes. Though not a primary food source for them, adult Alligator snappers have been known to kill and eat small alligators that they have been confined with, such as in a net, small bog, or poorly planned aquarium display.