• Common snapping turtles average 10 to 35 pounds, though some can weigh far more.Touching a Turtle image by Towards Ithaca from Fotolia.com
  
  Two species of snapping turtles exist in the world today: the alligator snapping turtle (Macrochelys temminckii) and the common snapping turtle (Chelydra serpentina), which includes four subspecies. Snapping turtles belong to the family Chelydridae and are among the largest of freshwater turtles in the world. Common "snappers" average about 10 to 35 pounds in the wild, but can weigh as much as 75 pounds. Alligator Snapping Turtles grow even larger, with the largest wild turtles reaching up to 251 pounds; one turtle achieved a hefty 316 pounds after 50 years in captivity.
  
  

Alligator Snapping Turtle

• Alligator snapping turtles have huge heads and a strongly hooked beak.horned snapping turtle image by Lucid_Exposure from Fotolia.com
  
  The alligator snapping turtle looks superficially similar to the common snapping turtle but has a much larger head, a more strongly hooked beak and prominent keels (knobs) on its top shell. They also have an extra row of scutes (keratinized plates) on each side of their shell, compared to common snapping turtles. Alligator snapping turtle occur from southwest Georgia and north Florida, east to eastern Texas and north into the Mississippi Valley, Kansas, Iowa and southwest Kentucky. However, the alligator snapping turtle is threatened or endangered in most states. Favoring lakes and rivers, this enormous turtle forages by sitting underwater and wiggling its pink, worm-like tongue to lure fish into its mouth.
  
  

Common Snapping Turtle

• Common snapping turtles have smaller heads and less-hooked beaks than alligator snapping turtles.common snapping turtle (chelydra serpentina) image by Bruce MacQueen from Fotolia.com
  
  The northern subspecies of the common snapping turtle (Chelydra serpentina serpentina) has the broadest distribution of all snapping turtles; it occupies southern and eastern Canada as well as the eastern two thirds of the United States (excluding most of Florida). Like all other subspecies of common snapping turtles, the northern subspecies is ubiquitous and inhabits nearly all freshwater aquatic habitats, including swamps, seepage ditches, ponds, lakes, streams and rivers. When defending themselves on land, common snapping turtles are quick to display a nasty disposition with their powerful jaws and highly mobile head. The common snapping turtle elevates its body and repeatedly hisses and strikes at perceived aggressors.
  
  

Florida Snapping Turtle

• The Florida snapping turtle (Chelydra serpentina Osceola) lives in Florida and southern Georgia. Although remarkably similar in appearance to the other three common snapping turtle subspecies, the Florida snapping turtle does have some morphological distinctions: it has long pointed tubercles on the upper surface of its neck (as opposed to rounded wart-like tubercles, which are seen on the neck of the northern subspecies) and tends to be smaller in body size than the northern subspecies. Like the other subspecies, Florida snapping turtles spend the majority of their time submerged in muddy, heavily-vegetated aquatic habitats waiting for fish or other aquatic prey to swim within reach.
  
  

Mexican Snapping Turtle

• According to "Turtles of the World" by Ernst and Barbour, the Mexican snapping turtle (Chelydra serpentina rossignoni) is found in the Atlantic lowlands of Mexico, from central Veracruz through the Yucatan Peninsula and down to western Belize, Guatemala and western Honduras. The Mexican snapping turtle can be differentiated from the Ecuadorian snapping turtle based on the presence of long, pointed tubercles on the Mexican snapper's neck (as opposed to short, rounded wart-like tubercles) and a few very technical characteristics. Mexican snappers, like all snapping turtles, travel considerable distances overland to nest and find new aquatic habitats. Some people think that Mexican snapping turtles are more aggressive in captivity than the other subspecies.
  
  

Ecuadorian Snapping Turtle

• The Ecuadorian snapping turtle (Chelydra serpentina acutirostris) is distributed from northern Honduras down through eastern Nicaragua, Costa Rica, Panama, Columbia and Ecuador, according to "Turtles of the World" by Ernst and Barbour. If geography can not be used to differentiate this subspecies from the Mexican snapping turtle, then look at the tubercles on the turtle's neck. The neck tubercles are shorter, rounder and more wart-like in the Ecuadorian snapping turtle. Ecuadorian snapping turtles, like the other subspecies, are omnivores (they eat plants and animals) and play vital roles in aquatic ecosystems as both scavengers of carrion and predators of live fish, snakes, turtles, invertebrates and sometimes even birds.