The North American river otter, also known as the northern river otter or common otter, is a semiaquatic mammal endemic to the North American continent found in and along its waterways and coasts. An adult North American river otter can weigh between 5.0 and 14 kg. Scientific name: Lontra canadensis Family: Mustelidae Order: Carnivora Phylum: Chordata Kingdom: Animalia