Myocaster coypus
What: A nutria is a large rodent with a scaly, rat-like tail and webbed hind feet.
Originated from:
How it arrived: Introduced into California in 1899 for fur farming. Escaped in 1937 from Avery Island into Louisiana. Later it was also released by the state and federal agencies as a fur source and to control alligator weed and water hyacinth. National Wetlands Research Center
It's spreading: By 1950 there were 20 million in coastal Louisiana. It continues to move into areas of fresh to brackish waters
Damage: Eats the roots of plants -- rice and cane, but also the tight knit of plants that hold marsh land together. This leads to coastal erosion.
Why it's a threat: It's only predators are alligators and humans. Their presence did, in fact, contribute to the rapid come back of alligators. They are also extremely prolific.
Control: Trapping and harvesting are the most successful means of control -- 95% of US trapping occurs in Louisiana. Currently their is a movement to create a market for nutria meat.