biology

Giant otter shrew

Giant otter shrew is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Giant otter shrew rather than just read about it. In short: 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.

Key takeaways

Giant otter shrew belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Giant otter shrew to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Giant otter shrew from memory before moving on to harder problems.

Reference excerpt

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 streams, wetlands and slow flowing larger rivers. It is the only species in the genus Potamogale. Otter shrews are most closely related to the tenrecs of Madagascar. They are nocturnal carnivores that feed on aquatic animals. Despite its name, the giant otter shrew is neither a true shrew (Soricidae) or otter (Lutrinae). The common name refers to their resemblance to otters with their flat face, stiff whiskers, 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 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 grams (11 oz) to 950 grams (34 oz). Head and body length is 290 millimetres (11 in) to 350 millimetres (14 in), and reaches 535 millimetres (21.1 in) to 640 millimetres (25 in) with tail.

Geographic range 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 the preserved rainforest of Kakamega, Kenya.

Habitat 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.

Behavior 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 visits discrete piles of feces that are sheltered and probably used to mark boundaries of territory. Giant otter shrews are solitary with one shrew occupying between 500 and 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 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.

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 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.

References

Illustrations

Worked examples

Example 1 — a first encounter with Giant otter shrew

Start with the simplest possible case. Write down what Giant otter shrew claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Giant otter shrew before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Giant otter shrew ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Giant otter shrew

In research: Giant otter shrew appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Giant otter shrew in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Giant otter shrew is common in secondary-school and first-year university syllabi. It links to neighbouring topics Afrosoricida, Aquatic mammals, IUCN Red List least concern species, so understanding it makes those chapters shorter.
In everyday life: Look for Giant otter shrew outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Giant otter shrew in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Giant otter shrew means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Giant otter shrew out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Giant otter shrew in simple terms?

Why does Giant otter shrew matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Giant otter shrew?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Giant otter shrew.