http://animal.discovery.com/fish/river-monsters/giant-snakehead/
Maximum Length: Up to nearly 6 feet
Maximum Weight: Up to 66 pounds
Extreme Aggression: As long as a full-grown person and weighing as much as a 5-year-old child, the giant snakehead is not only the largest member of the snakehead gang, but also the most violent. In Southeast Asia, there are stories of this fish attacking people unprovoked, especially during the breeding season. Giant snakehead parents aggressively guard their spawn, which is unusual for a fish. The father corrals and guides the fry while the mother patrols at a distance, ready to voraciously attack anything that looks like a threat — even something as large as a person.
U.S. Invasion: The giant snakehead has been sporadically sighted in U.S. waterways from Maine to Arkansas. Given its extremely aggressive nature and willingness to attack people, this is a huge cause for concern for the United States. The government is spending millions to fight this and other invasive snakehead species, mainly the northern and bullseye snakehead species, which have a much stronger foothold. These fish will eat anything that comes close — fish, frogs, lizards, rats, small ducks, snakes and even other snakeheads — and are causing massive environmental damage wherever they're found. They have no predators in the United States and, alarmingly, a female snakehead can produce over 100,000 young in a year.
A Monstrous Fish: There are around 30 different species of snakehead, ranging from the tropical Africa to the Far East and Russia. All are predators with streamlined bodies, sharp teeth and a reputation for extreme aggression. Snakeheads are also air-breathers. The fish will come to the surface, lift its head up, grab a mouthful of air and then submerge. The oxygen diffuses directly into a dense network of blood vessels encircling its swim bladder, an organ that doubles as a simple lung in snakeheads. This allows the fish to survive in stagnant areas where oxygen levels are low. It can even walk on land, using its soft pectorals to drag itself to new locations. It's said a snakehead can survive out of water for up to 4 days.
