The giant otter shrew (Potamogale velox) is a semiaquatic, carnivorous afrotherian mammal. It is found in the main rainforest block of central Africa from Nigeria to Zambia, with a few isolated populations in Kenya and Uganda. It lives in streams, wetlands and slow flowing larger rivers.[2] It is the only species in the genus Potamogale. Otter shrews are most closely related to the tenrecs of Madagascar.[3]
They are nocturnal carnivores that feed on aquatic animals. Despite its name, the giant otter shrew is not a true shrew (Soricidae). The common name refers to their resemblance to otters with their flat face, stiff whiskers, and muscular tails, and to their overall superficial similarity to true shrews.
The giant otter shrew is a mammal superficially similar to an otter in appearance. It is characterized by a long, flat tail, which it uses for swimming by sideways undulation like a fish. It has a muzzle covered with bristles, and flat shielded nostrils. It has dense, soft hair, silky on the tail.[2]
It has small eyes and external ears. Its fur consists of a dense undercoat and coarse guard hairs. It possesses counter-shading with dark brown on its back and whitish or yellowish under parts.[4] The tail is covered with a short, silky coat of fur and is compressed laterally which allow it to swim by horizontal undulations as in fishes and crocodiles.[1] Its legs are short and lack webbing so they are not used for swimming. The hind feet have a flap of skin along the inside that allows them to be held snugly against the body when swimming.[4] There are also two syndactylous (2nd and 3rd toes are fused) toes on the hind feet, used for grooming. On land P. velox is plantigrade.[4] Females have two mammae on the lower abdomen [4] for feeding young.
The mass ranges from 300 grams (11 oz) to 950 grams (34 oz). Head and body length is 290 millimetres (11 in) to 350 millimetres (14 in), and reaches 535 millimetres (21.1 in) to 640 millimetres (25 in) with tail.
Giant otter shrews are native to central Africa, from the southern regions of Nigeria (central Rainforest Zone), and then eastward through Equatorial Guinea, Gabon, and the Central African Republic, Chad, the Republic of Congo, the Democratic Republic of the Congo, South Sudan to the northern regions of Angola and Zambia. There is a small population that lives between Uganda and Kenya and the preserved rainforest of Kakamega, Kenya.[1][4]