There are two species of alligators known in the world--- the American alligators and the Chinese alligators. Several other species of alligators thrived in the world, but they are all driven to extinction. American and Chinese alligators differ in terms of their size and weight. The Chinese alligator weighs a bit less than its American counterpart. It is considerably smaller in size too.
The most ferocious aspect of crocodiles is that their teeth are visible while their mouths are shut. With alligators, the teeth are well concealed behind jaws when they have their mouths closed. But alligators rule the roost when it comes to speed of reptiles moving. They can clock a speed of 15mph on land. But you can see that an alligator's snout is much smaller than a crocodile's snout.
The color of an alligator's skin varies from yellow, brown and green. The color of their skin varies with their age. They become almost totally black in color when they get old. They have an armor over their bodies to guard them against predators. They have a strong and powerful tail to guide them thorough rough waters.
Alligators have toes on their legs separated by webbings as in ducks. This way, they find it quite easy to wade through watery ecosystem, and walk over sand and swamps too.
American alligators are known to thrive in freshwater environments. Freshwater rivers and lakes are known to have quite a population of alligators. Ponds, wetlands and marshes are also known to be the perfect habitat for alligators. Alligators are one of the most important links required to maintain the functionality of wetlands because they make alligator holes where plants and animals live during drought.