Giant otter shrew

The giant otter shrew (Potamogale velox) is a semiaquatic, carnivorous tenrec. 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 is found in streams, wetlands and slow flowing larger rivers. It is monotypic in the genus Potamogale.

Contrary to its name the giant otter shrew is not a true shrew (Soricidae) but a tenrec (Tenrecidae). The common name refers to their resemblance to otters with their flat face and stiff whiskers, and the tenrecs' overall superficial similarity to true shrews. They are nocturnal carnivores that feed on aquatic animals.

Description

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.

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. 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. 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. 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. Females have two mammae on the lower abdomen for feeding young.

Potamogalinae

Potamogalinae is the subfamily of "otter shrews", a group of semiaquatic riverine mammals in the family Tenrecidae 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 a strong, but superficial resemblance to true otters. 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.

Giant otter

The giant otter (Pteronura brasiliensis) is a South American carnivorous mammal. It is the longest member of the Mustelidae, or weasel family, a globally successful group of predators, reaching up to 1.7 m (5.6 ft). Atypical of mustelids, the giant otter is a social species, with family groups typically supporting three to eight members. The groups are centered on a dominant breeding pair and are extremely cohesive and cooperative. Although generally peaceful, the species is territorial, and aggression has been observed between groups. The giant otter is diurnal, being active exclusively during daylight hours. It is the noisiest otter species, and distinct vocalizations have been documented that indicate alarm, aggressiveness, and reassurance.

The giant otter ranges across north-central South America; it lives mostly in and along the Amazon River and in the Pantanal.

Its distribution has been greatly reduced and is now discontinuous. Decades of poaching for its velvety pelt, peaking in the 1950s and 1960s, considerably diminished population numbers. The species was listed as endangered in 1999 and wild population estimates are typically below 5,000. The Guianas are one of the last real strongholds for the species, which also enjoys modest numbers — and significant protection — in the Peruvian Amazonian basin. It is one of the most endangered mammal species in the neotropics. Habitat degradation and loss is the greatest current threat. The giant otter is also rare in captivity; in 2003, only 60 animals were being held.