Eurasian water shrew

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Eurasian water shrew [1]
Neomys fodiens TF 090829.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Eulipotyphla
Family: Soricidae
Genus: Neomys
Species:
N. fodiens
Binomial name
Neomys fodiens
(Pennant, 1771)
Eurasian Water Shrew area.png
Eurasian water shrew range
Synonyms

Crossopus fodiens Pallas [3]

The Eurasian water shrew (Neomys fodiens), known in the United Kingdom as the water shrew, is a relatively large shrew, up to 10 cm (4 in) long, with a tail up to three-quarters as long again. It has short, dark fur, often with a few white tufts, a white belly, and a few stiff hairs around the feet and tail. It lives close to fresh water, hunting aquatic prey in the water and nearby. Its fur traps bubbles of air in the water which greatly aids its buoyancy, but requires it to anchor itself to remain underwater for more than the briefest of dives.

Contents

Like many shrews, the water shrew has venomous saliva, making it one of the few venomous mammals, although it is not able to puncture the skin of large animals, nor that of humans. Highly territorial, it lives a solitary life and is found throughout the northern part of Europe and Asia, from Britain to Korea.

Description

The Eurasian water shrew grows to a length of about 10 cm (4 in) long with a tail length of 8 cm (3 in) and weight of 15 to 19 grams (12 to 58 oz). The dense short fur on the head, back and sides is greyish-black. The underparts are dirty white and are sharply demarcated from the dorsal surface. Sometimes they are tinged with rusty brown or occasionally are entirely dark grey. There is a white spot just behind the eye and often another near the small, rounded ear which is nearly hidden in the fur. The nose is black and the snout long and tapering. [4] The sharp, mostly white teeth are tipped with red, typical of the shrew subfamily Soricinae. The rusty colour comes from deposits of iron which serve to harden the enamel and which are concentrated in the tips of the teeth, particularly the molars which are the teeth most subject to wear. [5] The female has five pairs of nipples. The legs are short and the hind feet are powerful, with a fringe of short, stiff hairs on the outer edge, both of which features assist while it is driving its body through the water. The tail is slender and has a keel of short white hairs on the underside. [4] This shrew often utters shrill cries as it scurries about. [4]

Its karyotype has 2n = 52 and FN = 98. [1]

Distribution and habitat

The Eurasian water shrew is found throughout Europe with the exception of Iceland, Ireland, certain Mediterranean islands and the Balkans. [4] In Asia, its range extends from western Siberia and Asia Minor to North Korea and the Pacific coast of Siberia. [6] It rarely strays far from water and is found in and around ditches, streams, ponds, watercress beds, fish ponds, damp meadows and rough bushy ground adjoining water. [4]

Biology

Outside the breeding season, both male and female Eurasian water shrews maintain a territory but during the breeding season, only the females do so. At this time the males wander about visiting various female territories which indicates a promiscuous mating system without pair bonding. [7] On the whole they are solitary animals that seem to mutually avoid each other and there is no social hierarchy. [6]

The breeding season extends from April to September and much of the courtship takes place in the water. It either uses pre-existing burrows or digs its own. The nesting chamber is lined with moss, dry grass and leaves. Litters of four to eight or more young are born after a twenty-four-day gestation period. The young are tiny and helpless at birth. Their eyes open at fifteen to eighteen days and they are fully weaned at about seven weeks. Females can produce two or three litters a year. [4] The juveniles disperse after weaning, setting up their own territories. [7] They are sexually mature at six to eight months and their life expectancy is about three years. [6]

The Eurasian water shrew is active both night and day and is thoroughly at home in the water. Its short fur holds air and the skin does not get wet when it swims. When it emerges from the water it enters one of its many burrows and any moisture adhering to the fur is absorbed by the earth walls. It mostly feeds on aquatic organisms which are caught while it is swimming. It can remain underwater for twenty seconds before it has to surface to breathe. Larger prey items can be subdued by the toxic secretions from its submaxillary glands. They feed on crayfish, Freshwater snails, small fish, aquatic larvae, insects, spiders, amphibians, especially newts and small rodents are also eaten. It also feeds on land on such things as insect larvae. [6] According to a study, N. fodiens showed a higher consumption frequency of small invertebrates (larvae) compared to medium-sized earthworms and beetles. Additionally, medium-sized prey were consumed more gradually than small prey items (earthworms versus larvae and earthworms versus beetles). [8]

The Eurasian water shrew has a pair of glands under its jaw which produce venom, and this has been shown to be potent against the field vole (Microtus agrestis), and lethal at a minimum dose of fifteen milligrams per kilogram body weight. [9] The venom consists of a paralytic peptide which has been patented for use in neuromuscular therapy. [10] Overall, the Eurasian water shrew venom has stronger paralytic properties and lower cardioinhibitory activity. Thus acting as an immobilizing agent towards their prey or to organisms that may threaten them. [11]

Their behavior in captivity is described in Konrad Lorenz's book King Solomon's Ring .

Status

The International Union for Conservation of Nature lists the Eurasian water shrew as being of "Least concern" in its Red List of Threatened Species. This is because it has a large population distributed across a wide range and its population seems fairly stable. In some areas habitat degradation is occurring and wetlands are being drained but not to such an extent as to increase the status to "Vulnerable". Other possible threats include agricultural products and sewage which may pollute waterways and reduce the availability of food. In western Spain, a separate subspecies (N. f. niethammeri) has a very limited range and may be declining in numbers. [2]

Related Research Articles

<span class="mw-page-title-main">Shrew</span> Family of mammals

Shrews are small mole-like mammals classified in the order Eulipotyphla. True shrews are not to be confused with treeshrews, otter shrews, elephant shrews, West Indies shrews, or marsupial shrews, which belong to different families or orders.

<span class="mw-page-title-main">Solenodon</span> Family of mammals

Solenodons are venomous, nocturnal, burrowing, insectivorous mammals belonging to the family Solenodontidae. The two living solenodon species are the Cuban solenodon and the Hispaniolan solenodon. Threats to both species include habitat destruction and predation by non-native cats, dogs, and mongooses, introduced by humans to the solenodons' home islands to control snakes and rodents.

<span class="mw-page-title-main">Talpidae</span> Family of small insectivorous mammals

The family Talpidae includes the true moles who are small insectivorous mammals of the order Eulipotyphla. Talpids are all digging animals to various degrees: moles are completely subterranean animals; shrew moles and shrew-like moles somewhat less so; and desmans, while basically aquatic, excavate dry sleeping chambers; whilst the quite unique star-nosed mole is equally adept in the water and underground. Talpids are found across the Northern Hemisphere of Eurasia and North America, and range as far south as the montane regions of tropical Southeast Asia.

<span class="mw-page-title-main">Etruscan shrew</span> Species of mammal

The Etruscan shrew, also known as the Etruscan pygmy shrew, white-toothed pygmy shrew and Savi’s pygmy shrew, is the smallest known extant mammal by mass, weighing only about 1.8 g (0.063 oz) on average.

<span class="mw-page-title-main">Red-toothed shrew</span> Subfamily of mammals

The red-toothed shrews of the subfamily Soricinae are one of three living subfamilies of shrews, along with Crocidurinae and Myosoricinae. In addition, the family contains the extinct subfamilies Limnoecinae, Crocidosoricinae, Allosoricinae and Heterosoricinae. These species are typically found in North America, northern South America, Europe and northern Asia. The enamel of the tips of their teeth is reddish due to iron pigment. The iron deposits serve to harden the enamel and are concentrated in those parts of the teeth most subject to wear. Members of the genera Chimarrogale, Nectogale, Neomys (Nectogalini) and some members of Sorex (Soricini) are known as water shrews, due to having a semi-aquatic lifestyle.

<span class="mw-page-title-main">Northern short-tailed shrew</span> Species of mammal

The northern short-tailed shrew is the largest shrew in the genus Blarina, and occurs in the northeastern region of North America. It is a semifossorial, highly active, and voracious insectivore and is present in a variety of habitats like broadleaved and pine forests among shrubs and hedges as well as grassy river banks. It is notable in that it is one of the few venomous mammals. The specific epithet, brevicauda, is a combination of the Latin brevis and cauda, meaning "short tail".

<span class="mw-page-title-main">North American least shrew</span> Species of mammal

The North American least shrew is one of the smallest mammals, growing to be only up to 3 inches long. It has a long pointed snout and a tail never more than twice the length of its hind foot. The dense fur coat is either grayish-brown or reddish-brown with a white belly. Its fur becomes lighter in the summer and darker in the winter. Although similar in appearance to several species of rodents, all shrews are members of the order Eulipotyphla and should not be mistaken for a member of the order Rodentia. The North American least shrew's eyes are small and its ears are completely concealed within its short fur, giving it very poor eyesight and hearing.

<span class="mw-page-title-main">Marsh shrew</span> Species of shrew

The marsh shrew, also known as the Pacific water shrew, Bendire's water shrew, Bendire's shrew and Jesus shrew is the largest North American member of the genus Sorex. Primarily covered in dark-brown fur, it is found near aquatic habitats along the Pacific coast from southern British Columbia to northern California. With air trapped in its fur for buoyancy, marsh shrews can run for three to five seconds on top of the water. It measures about 16 cm (6.3 in) in length, including a 7-centimetre (2.8 in)-long tail, and weighs an average of 14.5–16 g (0.51–0.56 oz). The marsh shrew's diet consists mainly of invertebrates, which it hunts on land and in the water. They are rare; their populations are thought to be in decline, and they are considered endangered in parts of their range.

<span class="mw-page-title-main">Southern short-tailed shrew</span> Species of mammal

The southern short-tailed shrew is a gray, short-tailed shrew that inhabits the eastern United States.

<span class="mw-page-title-main">American shrew mole</span> Species of mammal

The American shrew mole is the smallest species of mole. It is the only living member of the genus Neurotrichus and the tribe Neurotrichini. It is also known as Gibb's shrew mole and least shrew mole. It is not closely related to the Asian shrew mole. The reason that it is called a "shrew mole" instead of being called either a "shrew" or a "mole" is because of its fur, which is a characteristic of shrews and its large head and heavy dentition, which is characteristic of moles.

<span class="mw-page-title-main">Hairy-tailed mole</span> Species of mammal

The hairy-tailed mole, also known as Brewer's mole, is a medium-sized North American mole. It is the only member of the genus Parascalops. The species epithet breweri refers to Thomas Mayo Brewer, an American naturalist.

<span class="mw-page-title-main">Common shrew</span> Species of mammal

The common shrew, also known as the Eurasian shrew, is the most common shrew, and one of the most common mammals, throughout Northern Europe, including Great Britain, but excluding Ireland. It is 55 to 82 millimetres long and weighs 5 to 12 grams, and has velvety dark brown fur with a pale underside. It is one of the rare venomous mammals. Juvenile shrews have lighter fur until their first moult. The common shrew has small eyes, a pointed, mobile snout and red-tipped teeth. It has a life span of approximately 14 months.

<span class="mw-page-title-main">Venomous mammal</span> Venom-producing animals of the class Mammalia

Venomous mammals are tetrapods of the class Mammalia that produce venom, which they use to kill or disable prey, to defend themselves from predators or conspecifics or in agonistic encounters. Mammalian venoms form a heterogeneous group with different compositions and modes of action, from four orders of mammals: Eulipotyphla, Monotremata, Primates, and Chiroptera. To explain the rarity of venom delivery in Mammalia, Mark Dufton of the University of Strathclyde has suggested that modern mammalian predators do not need venom because they are able to kill quickly with their teeth or claws, whereas venom, no matter how sophisticated, requires time to disable prey.

<span class="mw-page-title-main">Greater white-toothed shrew</span> Species of mammal

The greater white-toothed shrew is a small insectivorous mammal found in Europe and North Africa.

<span class="mw-page-title-main">Asian house shrew</span> Species of shrew

The Asian house shrew is a shrew species native to South and Southeast Asia that has been listed as Least Concern on the IUCN Red List since 2008 because of its large population and wide distribution. It has been introduced in several West Asian and East African countries. It is considered an invasive species and implicated in the demise of several island lizard species.

<span class="mw-page-title-main">Merida small-eared shrew</span> Species of mammal

The Merida small-eared shrew is a species of shrew that is endemic to Venezuela.

<i>Myosorex varius</i> Species of mammal

The forest shrew is a species of shrew in the mouse shrew family, Soricidae. It is found in Lesotho, South Africa, and Eswatini. Its natural habitats include temperate forests, dry savanna, Mediterranean-type shrubby vegetation, and temperate grassland. The term "forest shrews" in the plural is sometimes confusingly used to collectively refer to a different genus, Sylvisorex.

References

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  2. 1 2 Hutterer, R.; Meinig, H.; Bertolino, S.; Kryštufek, B.; Amori, A.; Sheftel, B.; Stubbe, M.; Samiya, R.; Ariunbold, J. & Buuveibaatar, V. (2017) [errata version of 2016 assessment]. "Neomys fodiens". IUCN Red List of Threatened Species . 2016: e.T29658A115170106. doi: 10.2305/IUCN.UK.2016-3.RLTS.T29658A22282586.en .
  3. Buchanan White, F. (1882). "The Mammalia of Scotland". The Scottish Naturalist. 6: 49.
  4. 1 2 3 4 5 6 Konig, Claus (1973). Mammals. Collins & Co. pp. 23–26. ISBN   978-0-00-212080-7.
  5. Strait, S. G.; Smith, S. C. (2006). "Elemental analysis of soricine enamel: pigmentation variation and distribution in molars of Blarina brevicauda". Journal of Mammalogy. 87 (4): 700–705. doi: 10.1644/05-MAMM-A-265R4.1 .
  6. 1 2 3 4 Fahey, Bridget (1999). "Neomys fodiens: Eurasian water shrew". Animal Diversity Web. University of Michigan Museum of Zoology. Retrieved 30 August 2013.
  7. 1 2 Cantoni, Debora (1993). "Social and spatial organization of free-ranging shrews, Sorex coronatus and Neomys fodiens (Insectivora, Mammalia)". Animal Behaviour. 45 (5): 975–995. doi:10.1006/anbe.1993.1116. S2CID   53162373.
  8. Kowalski, Krzysztof; Rychlik, Leszek (2018-04-03). "The role of venom in the hunting and hoarding of prey differing in body size by the Eurasian water shrew, Neomys fodiens". Journal of Mammalogy. 99 (2): 351–362. doi:10.1093/jmammal/gyy013. ISSN   0022-2372.
  9. Dufton, Mark J. (1992). "Venomous mammals". Pharmacology & Therapeutics. 53 (2): 199–215. doi:10.1016/0163-7258(92)90009-O. PMID   1641406.
  10. "Patent: Paralytic peptide for use in neuromuscular therapy". Patent 7485622. United States Patent Office. 3 February 2009. Retrieved 30 August 2013.[ dead link ]
  11. Kowalski, Marciniak, P., Rosiński, G., & Rychlik, L (2017). "Evaluation of the physiological activity of venom from the Eurasian water shrew Neomys fodiens". Frontiers in Zoology. 14 (1): 46. doi: 10.1186/s12983-017-0230-0 . PMC   5622582 . PMID   29026428.{{cite journal}}: CS1 maint: multiple names: authors list (link)