An alligator is a crocodilian in the genus Alligator of the family Alligatoridae. The name alligator is an anglicized form of the Spanish el lagarto ("the lizard"), the name by which early Spanish explorers and settlers in Florida called the alligator. There are two living alligator species: the American Alligator (Alligator mississippiensis) and the Chinese Alligator (Alligator sinensis).
Alligators are characterized by a broader snout and eyes more dorsally located than their crocodile cousins. Both living species also tend to be darker in color, often nearly black but color is extremely dependent on the water. Algae laden waters produce greener gators. Waters with a lot of tannic acid from overhanging trees are often darker. Also, in alligators only the upper teeth can be seen with the jaws closed (in contrast to true crocodiles, in which upper and lower teeth can be seen), though a lot of individuals bear jaw deformities which complicate this means of identification.
The eyes of a huge alligator will glow red and those of a smaller will glow green when a light is shined on them. This fact can be used to find alligators in the dark.
According to the Everglades National Park website, the largest alligator ever recorded in Florida was 17 feet 5 inches long (5.3 meters). The largest alligator ever recorded calculated 19 feet 2 inches (5.8 meters) and was found on Marsh Island, Louisiana. Few of the giant specimens were weighed, but the larger ones could have exceeded a ton in weight.
There are only two countries on earth that have alligators: the United States and China. The Chinese alligator is endangered and lives only in the Yangtze River valley though currently Rockefeller Wildlife refuge in southern Louisiana has various in captivity in an attempt to preserve the species. The American Alligator is found in the United States from the Carolinas to Florida and along the Gulf Coast. The majority of American Alligators inhabit Florida and Louisiana. In Florida alone there are an estimated more than 1 million alligators. The United States is the only nation on earth where both alligators and crocodiles live side by side. American Alligators live in freshwater environments, such as ponds, marshes, wetlands, rivers, and swamps. In China, they live only along the fresh water of the Yangtze River.