Potamogale velox, Du Chaillu, 1860

Russell A. Mittermeier & Don E. Wilson, 2018, Potamogalidae, Handbook of the Mammals of the World – Volume 8 Insectivores, Sloths and Colugos, Barcelona: Lynx Edicions, pp. 174-179 : 179

3.

Giant Otter-shrew

Potamogale velox

French: Potamogale / German: GrolRe Otterspitzmaus / Spanish: Musarana nutria gigante

Taxonomy. Cynogale velox Du Chaillu, 1860 ,

“mountains of the interior, or in the hilly country ... north and south of the equator,” Gabon . This species is monotypic.

Distribution. Central rainforest zone from the extreme SE tip of Nigeria, E through S Central African Republic to W Uganda and S to N Angola, S DR Congo, and NW Zambia, with an outlying population in SW Kenya (Kakamega Forest).

Descriptive notes. Head-body 305-337 mm, tail 235-290 mm, ear 15-23 mm, hindfoot 39-46 mm; weight 517-780 g. The Giant Otter-shrew is very large—an

order of magnitude larger than its closest relatives in the genus Micropotamogale . It has a strong superficial resemblance to an otter, with short, sleek pelage and thick, laterally compressed tail. Fur is soft, thick, and rich brown dorsally, shading to white ventrally. Chin, throat, and upper chest are white. Coat is thick with white underfur. Ears are relatively small. Tail is coated in dense fur along its entire length, being longer in the first one-quarter and shorter along the rest oftail. Limbs are relatively short and same color as dorsum. There are five digits on forefeet and hindfeet, all of which lack webbing. Second and third digits of hindfeet are fused to form comb used for grooming. There are four pairs of nipples: two pectoral, one abdominal, and one inguinal.

Habitat. Streams and small rivers in lowland rainforests. One Giant Otter-shrew was found in the larger Ivindo River, Gabon, several hundred meters wide. They are found up to elevations of 1800 m in the Albertine Rift.

Food and Feeding. The Giant Otter-shrew preys on various aquatic animals including fish, crabs, and other crustaceans; frogs are rarely eaten.

Breeding. There is little information available, but litters of Giant Otter-shrews have 1-2 young that are born throughout the year.

Activity patterns. The Giant Otter-shrew is nocturnal and almost exclusively aquatic, and individuals appear to make several foraging bouts per night. Unique among mammals, it swims by lateral undulations of its muscular tail, with forelimbs are held close to the body when swimming through water. During the day, the Giant Otter-shrew rests in a burrow, located in the bank of a river or stream, typically under a tree among its roots; entrance can be above or below surface of the water.

Movements, Home range and Social organization. Home range and movement patterns of Giant Otter-shrews are not known. Densities in suitable habitat may reach one territorial individual per 500 m of stream length, with maximum densities of c.1 ind/100 m. Latrines are probably used to mark territorial boundaries.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Although the Giant Otter-shrew is not currently under conservation threat,it is widely hunted for its skin and it occurs in stream/river habitat that is sensitive to degradation by increased soil erosion resulting from deforestation.

Bibliography. Aggundey (1977), Dubost (1965), Nicoll (1985b), Nicoll & Rathbun (1990), Vogel (2013d).

Figures

1. Nimba Otter-shrew (Micropotamogale lamotte), 2. Rwenzor Otter-shrew (Micropotamogale ruwenzorii), 3. Giant Otter-shrew (Potamogale velox)

Distribution. Central rainforest zone from the extreme SE tip of Nigeria, E through S Central African Republic to W Uganda and S to N Angola, S DR Congo, and NW Zambia, with an outlying population in SW Kenya (Kakamega Forest).