Otter Otter Otters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic or marine, with diets based on fish and invertebrates. Lutrinae is a branch of the weasel family Mustelidae, which also includes badgers, honey badgers, martens, minks, polecats, and wolverines. The word "otter" derives from the Old English word "otor" or "oter". This, and cognate words in other Indo-European languages, ultimately stem from the Proto-Indo-European language root *wódr̥, which also gave rise to the English word "water". An otter's den is called a holt or couch. Male otters are called dogs or boars,
North American river otter North American river otter The North American river otter ("Lontra canadensis"), also known as the northern river otter or the 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 . The river otter is protected and insulated by a thick, water-repellent coat of fur. The North American river otter, a member of the subfamily Lutrinae in the weasel family (Mustelidae), is equally versatile in the water and on land. It establishes a burrow close to the water's edge in river,