Otters (Lutrinae) are about a dozen species of medium-sized aquatic mustelid carnivorous mammals found over much of the globe. The largest species is the giant otter of Brazil, which can grow to a length of six feet.
Typically otters feed upon fish and crustaceans such as crayfish, and live in rivers. The sea otter and marine otter live in the sea, and supplement their diet with molluscs such as abalones. The sea otter is one of the few tool-using mammals, using stones to break the molluscan shells.
Sea otters were historically heavily hunted for their valuable fur, and wiped out over much of their range. In Europe, the common river otter was hunted by specially bred dogs such as otterhounds and Airedale terriers, because of the damage they did to salmon and trout fisheries.
- River Otter, Videos © 2008 Yellowstone Association