The Atlantic tarpon, Megalops atlanticus, inhabits coastal waters, estuaries, lagoons, and rivers. It feeds almost exclusively on schooling fish and occasionally crab. It is capable of filling its swim bladder with air and absorbing oxygen from it, like a primitive lung.This gives it an advantage when oxygen levels in the water are low. Specimens have been recorded at up to 250 centimetres (98 in) in length and weighing up to 161 kilograms (350 lb). The Atlantic tarpon is also known as the silver king.

In appearance, it is greenish or bluish on top, and silver on the sides. The large mouth is turned upwards, and the lower jaw contains an elongated bony plate. The last ray of the dorsal fin is much longer than the others, reaching nearly to the tail.

The Atlantic tarpon is found in the Atlantic ocean typically in tropical and subtropical regions, though it has been reported as far north as Nova Scotia and the atlantic coast of Southern France, and as far south as Argentina. As with all Elopiformes it is found in coastal area, spawning at sea. Diet includes smaller fish and crustaceans.

It is the official state saltwater fish of Alabama.