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.
Otters have long, slim bodies and relatively short limbs. Their most striking anatomical features are the powerful webbed feet used to swim, and their seal-like abilities holding breath underwater. Most have sharp claws on their feet and all except the sea otter have long, muscular tails. Their pelts have soft, thick underfur which is protected by an outer layer of long guard hairs. This traps a layer of air which keeps them dry, warm, and somewhat buoyant under water.
- Otters are carnivorous mammals in the subfamily Lutrinae
- The 13 extant otter species are all semiaquatic
- Otters have long, slim bodies and relatively short limbs
- Their most striking anatomical feature is their elongated, tapered tail
- Otters are proficient swimmers and are mostly found in bodies of water
- They have very sensitive whiskers which they use to locate prey
- Otters are social animals and live in groups called "rafts"
- The otter's primary predators are humans and large birds of prey