American Alligator - Description

Description

An alligator can live up to 30 to 50 years. In adult male American alligators, length averages 3.4 m (11 ft) while in smaller females, it averages 2.6 m (8.5 ft). Occasionally, a large, old male may measure in excess of 4 m (13 ft). There have been reports during the 19th and 20th centuries of larger males reaching 5 to 6 m (16 to 20 ft). The largest reported size was a male killed in 1890 on Marsh Island, Louisiana and reportedly measured at 5.8 m (19 ft) in length but no voucher specimen was available since the alligator was left on a muddy bank after having been taped due to having been too massive to relocate. Adult males may weigh around 227 kg (500 lb) while females weigh around 91 kg (200 lb). Wild alligators range from long and slender to short and robust, possibly due to variations in factors like growth rate, diet and climate. Alligators have broad snouts, especially in captive individuals. When the jaws are closed, the edge of the upper jaws covers the lower teeth which fit into the jaws' depressions. Like the spectacled caiman, this species has a bony nasal ridge, though it is less prominent. Dorsally, adult alligators may be olive, brown, gray or black in color while their undersides are cream colored. The teeth number from 74–84.

When on land, the alligator moves either by sprawling or walking, the latter involving the reptile lifting its belly off the ground. The sprawling of alligators and other crocodilians is not identical to the sprawling of salamanders and lizards, being similar to walking. Thus the two forms of territorial locomotion can be term the "low walk" and the "high walk". Unlike most another land vertebrates, alligators increase their speed through the distal rather than proximal ends of their limbs. In the water, alligators swim like fish; moving their pelvic regions and tails from side to side. American alligators have the strongest laboratory-measured bite of any living animal, measured at up to 9,452 newtons (2,125 lbf) in laboratory conditions. It should be noted that this experiment has not (at the time of the paper published) been replicated in any other crocodilians. During respiration, airflow is unidirectional; looping through the lungs during inhalation and exhalation.

Some alligators are missing an inhibited gene for melanin, which makes them albino. These alligators are extremely rare and almost impossible to find in the wild. They could survive only in captivity as they are very vulnerable to the sun and predators.