The giant otter shrew (''Potamogale velox'') is a

semiaquatic In biology, semiaquatic can refer to various types of animals that spend part of their time in water, or plants that naturally grow partially submerged in water. Examples are given below. Semiaquatic animals Semiaquatic animals include: * Verte ...

, carnivorous

afrotheria Afrotheria ( from Latin ''Afro-'' "of Africa" + ''theria'' "wild beast") is a clade of mammals, the living members of which belong to groups that are either currently living in Africa or of African origin: golden moles, elephant shrews (also know ...

n mammal. It is found in the main rainforest block of

central Africa Central Africa is a subregion of the African continent comprising various countries according to different definitions. Angola, Burundi, the Central African Republic, Chad, the Democratic Republic of the Congo, the Republic of the Congo, ...

from

Nigeria Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf o ...

Zambia Zambia (), officially the Republic of Zambia, is a landlocked country at the crossroads of Central Africa, Central, Southern Africa, Southern and East Africa, although it is typically referred to as being in Southern Africa at its most cent ...

, with a few isolated populations in

Kenya ) , national_anthem = "Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...

and

Uganda }), is a landlocked country in East Africa East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territor ...

. It lives in streams, wetlands and slow flowing larger rivers. It is the only species in the genus ''Potamogale''.

Otter shrew Potamogalidae is the family of "otter shrews", a group of semiaquatic riverine afrotherian mammals indigenous to sub-Saharan Africa. They are most closely related to the tenrecs of Madagascar, from which they are thought to have split about 47– ...

s are most closely related to the

tenrec A tenrec is any species of mammal within the afrotherian family Tenrecidae endemic to Madagascar. Tenrecs are wildly diverse; as a result of convergent evolution some resemble hedgehogs, shrews, opossums, rats, and mice. They occupy aquatic, a ...

s of Madagascar. They are

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

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 Otters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic, or marine, with diets based on fish and invertebrates. Lutrinae is a branch of the Mustelidae family, which also includes wea ...

with their flat face, stiff

whiskers Vibrissae (; singular: vibrissa; ), more generally called Whiskers, are a type of stiff, functional hair used by mammals to touch, sense their environment. These hairs are finely specialised for this purpose, whereas other types of hair are c ...

, and muscular tails, and to their overall superficial similarity to true shrews.

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

crocodile Crocodiles (family (biology), family Crocodylidae) or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term crocodile is sometimes used even more loosely to inclu ...

s. 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 151px, Portion of a human skeleton, showing plantigrade habit In terrestrial animals, plantigrade locomotion means walking with the toes and metatarsals flat on the ground. It is one of three forms of locomotion adopted by terrestrial mammals. T ...

. Females have two mammae on the lower abdomen for feeding young. The mass ranges from to . Head and body length is to , and reaches to with tail.

Geographic range

Giant otter shrews are native to central Africa, from the southern regions of

(central Rainforest Zone), and then eastward through Equatorial

Guinea Guinea ( ),, fuf, 𞤘𞤭𞤲𞤫, italic=no, Gine, wo, Gine, nqo, ߖߌ߬ߣߍ߫, bm, Gine officially the Republic of Guinea (french: République de Guinée), is a coastal country in West Africa. It borders the Atlantic Ocean to the we ...

Gabon Gabon (; ; snq, Ngabu), officially the Gabonese Republic (french: République gabonaise), is a country on the west coast of Central Africa. Located on the equator, it is bordered by Equatorial Guinea to the northwest, Cameroon to the north ...

, and the

Central African Republic The Central African Republic (CAR; ; , RCA; , or , ) is a landlocked country in Central Africa. It is bordered by Chad to the north, Sudan to the northeast, South Sudan to the southeast, the DR Congo to the south, the Republic of th ...

Chad Chad (; ar, تشاد , ; french: Tchad, ), officially the Republic of Chad, '; ) is a landlocked country at the crossroads of North and Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic ...

, the

Republic of Congo The Republic of the Congo (french: République du Congo, ln, Republíki ya Kongó), also known as Congo-Brazzaville, the Congo Republic or simply either Congo or the Congo, is a country located in the western coast of Central Africa to the w ...

, the

Democratic Republic of the Congo The Democratic Republic of the Congo (french: République démocratique du Congo (RDC), colloquially "La RDC" ), informally Congo-Kinshasa, DR Congo, the DRC, the DROC, or the Congo, and formerly and also colloquially Zaire, is a country in ...

South Sudan South Sudan (; din, Paguot Thudän), officially the Republic of South Sudan ( din, Paankɔc Cuëny Thudän), is a landlocked country in East Africa. It is bordered by Ethiopia, Sudan, Central African Republic, Democratic Republic of the C ...

to the northern regions of

Angola , national_anthem = " Angola Avante"() , image_map = , map_caption = , capital = Luanda , religion = , religion_year = 2020 , religion_ref = , coordina ...

and

. There is a small population that lives between Uganda and Kenya and the preserved rainforest of Kakamega, Kenya.Tamaska, Gabriel. (2001-10-05
ADW: Potamogale velox
Animaldiversity.ummz.umich.edu. Retrieved on 2013-01-11.

Habitat

This species prefers fresh water aquatic microhabitats in the

rainforest Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfores ...

. Preferred environments include fast flowing rivers, streams, swamps, coastal rivers,''Potamogale velox''
fieldmuseum.org 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.

Behavior

The giant otter shrew builds

burrow An Eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of locomotion. Burrows provide a form of sh ...

s among riverbank crevices. It chooses dry leaves with which to line its nest. This is also where breeding takes place. The

s 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 visits discrete piles of

feces Feces ( or faeces), known colloquially and in slang as poo and poop, are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. Feces contain a relati ...

that are sheltered and probably used to mark boundaries of territory. Giant otter shrews are

solitary Solitary is the state of being alone or in solitude. The term may refer to: * shortened form of solitary confinement * Solitary animal, an animal that does not live with others in its species * Solitary but social, a type of social organization in ...

with one shrew occupying between 500–1,000 m of stream.

Food habits

''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

vibrissa Vibrissae (; singular: vibrissa; ), more generally called Whiskers, are a type of stiff, functional hair used by mammals to sense their environment. These hairs are finely specialised for this purpose, whereas other types of hair are coarser ...

e 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 Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Th ...

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 Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

, and freshwater

prawns Prawn is a common name for small aquatic crustaceans with an exoskeleton and ten legs (which is a member of the order decapoda), some of which can be eaten. The term "prawn"Mortenson, Philip B (2010''This is not a weasel: a close look at nature ...

. In captivity it eats 15–20 crabs per night.

Lifespan

Giant otter shrews fare very poorly in captivity. Captive specimens have been recorded to deteriorate in health very quickly, living only 1– 14 days.

Reproduction

Giant otter shrews breed during the wet/rainy season. They give birth to one or two young 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.

Conservation status

Currently this species is listed as being of least concern by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

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 Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...

and

deforestation Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated d ...

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.

References

{{Taxonbar, from=Q474780

giant otter shrew 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 str ...

Mammals of West Africa Mammals of Central Africa Mammals of East Africa Aquatic mammals