Family Lutrinae (River Otters)
* Sea Otter (Enhydra lutris): Found in the North Pacific Ocean, these are the smallest marine mammals in the world and are known for their thick fur. There are three subspecies: the Northern Sea Otter (E. l. lutris), the Californian Sea Otter (E. l. nereis), and the Russian Sea Otter (E. l. lutris).
* Giant Otter (Pteronura brasiliensis): Found in South America, these are the largest living otter species. They are social animals and live in family groups.
* North American River Otter (Lontra canadensis): Found in North America, these otters are highly adaptable and live in a variety of habitats. They are known for their playful nature.
* Neotropical River Otter (Lontra longicaudis): Found in Central and South America, these otters are smaller than the North American River Otter and are often found near rivers and lakes.
* Marine Otter (Lontra felina): Found in South America, these are the smallest otter species and are adapted to living in rocky coastal areas.
* Smooth-coated Otter (Lutrogale perspicillata): Found in Southeast Asia, these otters are known for their smooth, shiny fur. They are semi-aquatic and live in rivers and lakes.
* Eurasian Otter (Lutra lutra): Found in Europe and Asia, these otters are adaptable and live in a variety of habitats, including rivers, lakes, and coastal areas.
* Oriental Small-clawed Otter (Aonyx cinerea): Found in Southeast Asia, these otters are the smallest otter species and are known for their small claws. They are primarily fish eaters and are often found in mangrove swamps and rivers.
Family Mustelidae (Other Otters)
* African Clawless Otter (Aonyx capensis): Found in Africa, these otters are known for their lack of claws. They are semi-aquatic and live in rivers, lakes, and coastal areas.
* Sea Otter (Enhydra lutris): While it's technically in the Lutrinae family, it's often grouped with the sea otters due to its marine adaptation.
Important Note:
There are also several extinct otter species, such as the Japanese Otter (Lutra nippon) and the (**Lontra provocax).