Potamogalinae is the subfamily of "otter shrews", a group of semiaquatic riverine mammal

Mammal

Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

s in the family Tenrecidae

Tenrecidae

Tenrecidae is a family of mammals found on Madagascar and parts of Africa. Tenrecs are widely diverse, resembling hedgehogs, shrews, opossums, mice and even otters, as a result of convergent evolution. They occupy aquatic, arboreal, terrestrial and fossorial environments...

 indigenous to Subsaharan Africa. All otter shrews are carnivorous, preying on any aquatic animal they can find with their sensitive whiskers. As their common name suggests, they bear an extreme resemblance to true otter

Otter

The Otters are twelve species of semi-aquatic mammals which feed on fish and shellfish, and also other invertebrates, amphibians, birds and small mammals....

s. They move through the water by undulating their tail in a side-to-side motion similar to the motions made by a crocodile swimming.

Species

Three species of otter shrew are recognized.

• Dwarf otter shrews, genus Micropotamogale
  Micropotamogale
  Micropotamogale is a genus of small, otter-like tenrecs native to riverine habitats of West African rainforests. They feed on aquatic animals and insects they can find and capture.Two species are recognized:...
  
  
  • Nimba Otter Shrew
    Nimba Otter Shrew
    The Nimba Otter Shrew is a dwarf otter shrew and belongs to the mammal family Tenrecidae. It is native to Mount Nimba in West Africa. Also known as Pygmy Otter Shrew, it shares the genus Micropotamogale with the Ruwenzori Otter Shrew.-Description:The Nimba Otter Shrew has a body length of 12-20 cm...
    
     (Micropotamogale lamottei)
  • Ruwenzori Otter Shrew
    Ruwenzori Otter Shrew
    The Ruwenzori Otter Shrew is a species of semiaquatic mammal in the family Tenrecidae. It is found in Democratic Republic of the Congo and Uganda. Its natural habitat is rivers. It is threatened by habitat loss....
    
     (Micropotamogale ruwenzorii)
• Giant Otter Shrew, genus Potamogale
  • Giant Otter Shrew
    Giant Otter Shrew
    The Giant Otter Shrew is a semiaquatic, carnivorous tenrec. It is found in the main rainforestblock of Central Africa from Biafra to Zambia, with a few isolated populations in Kenya and Uganda. It is found in streams, wetlands, and slowly flowing larger rivers...
    
    (Potamogale velox)