Potamogale veloxgiant otter shrew

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Geographic Range

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).

Habitat

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).

  • Aquatic Biomes
  • rivers and streams
  • Range elevation
    0 to 1800 m
    0.00 to 5905.51 ft

Physical Description

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
    10.57 to 33.48 oz
  • Range length
    535 to 640 mm
    21.06 to 25.20 in

Reproduction

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

Lifespan/Longevity

Little in known about the longevity of P. velox, but when held in captivity individuals quickly deteriorate (Nicoll, 1985).

  • Range lifespan
    Status: captivity
    1 to 14 days

Behavior

P. velox is a strong, agile swimmer. Activity starts at dusk and continues into the night. P. velox digs burrows in the stream bank with underwater entrances and shelters there during the day. 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 more frequently than when traveling 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 above the stream flood line (Nicoll, 1985).

Communication and Perception

Food Habits

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

Conservation Status

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).

Other Comments

Information on P. velox is scarce, and much of it is in languages other than English.

Despite it's common name "shrew" it should be noted that P. velox is a tenrec, not a shrew.

Contributors

Gabriel Tamaska (author), University of Michigan-Ann Arbor, Ondrej Podlaha (editor), University of Michigan-Ann Arbor.

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

fertilization

union of egg and spermatozoan

freshwater

mainly lives in water that is not salty.

insectivore

An animal that eats mainly insects or spiders.

internal fertilization

fertilization takes place within the female's body

molluscivore

eats mollusks, members of Phylum Mollusca

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

piscivore

an animal that mainly eats fish

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

swamp

a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.

tactile

uses touch to communicate

References

"African Mammals Databank (*Potamogale Velox*)" (On-line). Accessed October 5, 2001 at http://www.gisbau.uniroma1.it/amd/amd028b.html.

Kingdon, J. 1997. Giant otter shrew. Pp. 137 in The Kingdon field guide to African Mammals. London and New York: Natural World: Academic Press.

Nicoll, M. 1985. The biology of the giant otter shrew *Potamogale velox*. National Geographic Society Research Reports, 21: 331-337.

Walker, E., F. Warnic, S. Hamlet, K. Lange, M. Davis. 1983. Giant African Water or Otter Shrew. Pp. 112 in J Paradiso, ed. Mammals of the World. Baltimore, Maryland: Johns Hopkins University Press.