This species occurs in the central rainforest zone and peripheral areas from Nigeria (Cross River) eastwards through Cameroon, Equatorial Guinea, Gabon, Central African Republic, Chad, Republic of Congo, Sudan, Democratic Republic of Congo (DRC), to western Uganda and western Kenya and Tanzania, and southwards to central Angola and northern Zambia (Corbet 1974). It is found from sea level up to 1,800 m asl. Most of the recent records have been from eastern DRC, in places such as the Okapi Wildlife Reserve, Ituri Forest (P.J. Stephenson pers. obs.), the Itombwe Massif (T. Demos pers. comm.) and in the Upper Lualaba (J. Kerbis Peterhans pers. comm.).
Potamogale velox is found only in central Africa, from the southern regions of Nigeria, Gabon, and The Central African Republic to the Northern regions of Angolia and Zambia. It is rarely found west of Tanzania and Uganda. One small population lives between Uganda and Kenya (African Mammal Databank).
Biogeographic Regions: ethiopian (Native )
The Giant Otter Shrew got its common name because of its physical resemblance to otters. It has a broad, flat muzzle covered with stiff whiskers, and flaps of skin that seal its nostrils when diving. It has small eyes and external ears. The thick round body is covered with a dense undercoat and course guard hairs. P. velox has a dark brown back and whitish under parts. The tail is covered with a short, silky coat of fur. It is compressed laterally, and allows P. velox to swim with a fish-like motion (Knigdon, 1997; Nicoll, 1985; Walker, 1983). Legs, which are short and lack webbed digits, are not used for swimming. The hind feet have a flap if skin along the inside that allows them to be held snugly against the body when swimming. There are also two syndactylous toes on the hind feet, used for grooming. On land P. velox is plantigrade (Walker, 1983; Nicoll, 1985). Females have two mammae on the lower abdomen (Nicoll, 1985).
Range mass: 300 to 950 g.
Range length: 535 to 640 mm.
Other Physical Features: endothermic ; bilateral symmetry
Habitat and Ecology
A very muscular tail enables efficient swimming by horizontal undulations (Kingdon 1974), as in fishes and crocodiles. This method of swimming is unique amongst aquatic mammals (e.g., pinnipeds, cetaceans) which usually swim by undulations in a vertical plane. The forelimbs are not used for propulsion. Moving on land it is rather clumsy. The body pelage is groomed with comb-like structure formed by the fusion of second and third toes. It is nocturnal with several bouts of activity each night (Dubost 1965, Nicoll 1985), and it rests during the daytime in a burrow in river bank. When disturbed, it escapes in the water. Movements over long distances are always by water, never over-land.
It forages in water, feeding on aquatic prey. It hunts by diving and each dive lasting for only a few seconds. Prey are located using the sensitive vibrissae and odour; the eyes apparently are not used to locate prey. Analysis of stomach contents and faeces show that the diet is mainly fishes, crabs, shrimps and water insects; frogs are eaten rarely (Dubost 1965). In captivity it eats 15-20 crabs per night (Durrell 1953).
Latrines are probably used to mark the boundaries of territory (Dubost 1965). The den, with the nest chamber, is entered from below or above water level and is usually placed under a tree.
This species breeds during wet and dry seasons.
P. velox prefers aquatic environments in the central African rain forest. Its preferred habitats include both high and low order streams, swamps, and during the rainy season some animals may migrate to small forest pools (Kingdon, 1997; Walker 1983).
Range elevation: 0 to 1800 m.
Habitat Regions: freshwater
Terrestrial Biomes: rainforest
Aquatic Biomes: rivers and streams
P. velox is a nocturnal predator, hunting primarily by touch and scent in calm pools. It searches both the pool and the bank for food. It prefers areas that have cover to retreat to when it feels threatened (Nicoll, 1985). P. velox attacks prey using sharp bites, sometimes pinning the prey with its fore feet, and flipping crabs over to attack their ventral surface. When attacking larger prey P. velox hisses, and avoids crabs larger than 7 cm across (Nicoll, 1985; Walker, 1983). The prey preference varies among individuals; some prefer crabs; others, frogs, or even fish. Frogs are eaten headfirst and fish are pulled into manageable bits. Prey is consumed on the bank (Nicoll, 1985). They also eat insects, mollusks, and prawns.
Animal Foods: amphibians; fish; insects; terrestrial non-insect arthropods; mollusks
Primary Diet: carnivore (Eats terrestrial vertebrates, Piscivore , Insectivore , Eats non-insect arthropods, Molluscivore )
Known prey organisms
This list may not be complete but is based on published studies.
Life History and Behavior
Perception Channels: tactile ; chemical
Little in known about the longevity of P. velox, but when held in captivity individuals quickly deteriorate (Nicoll, 1985).
Status: captivity: 1 to 14 days.
Males move long distances in search of mates and it is thought that males rut during the wet season (Nicoll, 1985).
Little is known about the reproductive patterns of P. velox, but females examined were generally developing twins (Nicoll, 1985).
Breeding season: Wet season
Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal )
IUCN Red List Assessment
Red List Category
Red List Criteria
- Least Concern (LC)
- 2006Least Concern (LC)
- 1996Endangered (EN)
The habitat of P. velox is highly fragmented (Walker, 1983; African Mammal Databank; Nicoll, 1985). While they can tolerate seasonally cloudy streams, streams muddied from erosion and deforestation are little used (Walker, 1983; African Mammal Databank). Habitat quality is apparently important to this species. Some drown in fishing nets or fish traps (Walker, 1983; Kingdon, 1997), and members of this species have not survived well in captivity (Nicoll, 1985). There is ongoing research about the effects of human activity on them (African Mammal Databank).
US Migratory Bird Act: no special status
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Soil erosion caused by deforestation increases the murkiness and opaqueness of waterways which seems to be to the detriment of this species. This is a particular problem in Cameroon (Nicoll 1985), where forest clearance, soil erosion and resultant murky water in forest streams resulted in the disappearance of the local Potamogale population. This species may therefore be in decline in most of its range states where the loss of native forest due to timber extraction, agriculture and infrastructure development is an ongoing threat. It is reported to be widely hunted for its skin and is accidentally trapped in nets or fish traps, but the extent to which such offtakeis a threat to the survival of the speciesis unknown.
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.
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.
The mass ranges from 300 to 950 g. Head and body length is 290–350 mm, and reaches 535–640 mm 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 preserved rainforest of Kakamega, Kenya.
This species prefers fresh water aquatic microhabitats in the rainforest. Preferred environments include fast flowing rivers, streams, swamps, coastal rivers, and during rainy season some may retreat to small forest pools (altitude range from 0–1,800m). River banks provide good habitats for breeding and nesting. These animals make burrows with an entrance below water level (like otters) and during the day find shelter there and then become active in the afternoon.
The giant otter shrew builds burrows among riverbank crevices. It chooses dry leaves with which to line its nest. This is also where breeding takes place. The burrows are frequently changed. When foraging, otter shrews take frequent grooming breaks. When traveling upstream the otter shrew travels on the bank and then swims downstream. The night foraging routine is regular and predictable, and covers up to 800 meters a night. P. velox regularly visited discrete piles of feces that were sheltered and probably used to mark boundaries of territory.
P. velox is a nocturnal predator, hunting primarily by touch and scent in and around calm pools. Each dive lasts only seconds. P. velox searches both within the pool and along the bank for prey using the sensitive vibrissae and odor and apparently not eyesight. It prefers areas that have cover to retreat to when it feels threatened. P. velox attacks prey using sharp bites, sometimes pinning the prey with its fore feet, and flipping crabs over to attack their weaker ventral surface. They usually avoid crabs larger than 7 cm across. The prey preference varies among individuals; some prefer crabs; others, frogs or fish. Frogs are eaten headfirst and fish are pulled apart into manageable bits. Prey is consumed on the bank. P. velox also eats insects, mollusks, and freshwater prawns. In captivity it eats 15–20 crabs per night.
Giant otter shrews fare very poorly in captivity. Captive specimens have been recorded to deteriorate in health very quickly, living only 1– 14 days.
Giant otter shrews breed during the wet/rainy season. They reproduce sexually and give birth to one or two pup per litter, once or twice a year. Males move long distances via water in search of mates and it is thought that males rut (or fight) during the wet season.
Currently this species is of least concern because its declining rate is not significant enough to move to the next category. However it is on the decline. One of the major threats to this species is the soil erosion caused by deforestation especially in Cameroon. While they can tolerate seasonally cloudy streams, streams muddied from erosion and deforestation are little used. Some drown in fishing nets or fish traps, and members of this species have not survived well in captivity. There is ongoing research about the effects of human activity on them. It is also hunted extensively for its skin.
|Wikimedia Commons has media related to Potamogale velox.|
|Wikispecies has information related to: Potamogale|
- Vogel, P. (Afrotheria Specialist Group) (2008). Potamogale velox. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 29 December 2008.
- Kingdon, Jonathan (1997). The Kingdon Field Guide to African Mammals. San Diego: AP Natural World. p. 137. ISBN 0-12-408355-2.
- Tamaska, Gabriel. (2001-10-05) ADW: Potamogale velox. Animaldiversity.ummz.umich.edu. Retrieved on 2013-01-11.
- Potamogale velox, fieldmuseum.org
- Bronner, G. N.; Jenkins, P. D. (2005). "Order Afrosoricida". In Wilson, D. E.; Reeder, D. M. Mammal Species of the World (3rd ed.). Johns Hopkins University Press. p. 76. ISBN 978-0-8018-8221-0. OCLC 62265494.