water shrew

mammal
      any of 12 species of amphibious shrews (shrew) that have a broad, fleshy muzzle, large chest, and long hind legs and digits. Most water shrews live in montane habitats and forage in clear, cold streams and small rivers. They use all four feet to swim, but most of the propulsive force comes from the hind feet. Their relatively large brain is associated with enlarged nerves leading to the shrews' abundant and sensitive whiskers, which are used to locate prey underwater by touch. Water shrews do not hunt by using smell, sight, or hearing, as their olfactory regions of the brain are reduced, their eyes small, and their ears hidden in fur.

      Their soft, very dense fur is blackish but slightly paler or white on the underparts. The longer hairs in its coat, instead of being rounded, as in terrestrial shrews, are grooved on each side (H-shaped in cross section), and the grooves contain numerous ridges. This configuration helps trap air, providing the coat with water-repellent properties and increased insulation to counter heat loss while submerged. The long tail is finely furred.

      The elegant water shrew (Nectogale elegans) of continental Southeast Asia is the most specialized for aquatic life. Only occasionally emerging from the water, it eats only aquatic insect larvae and nymphs. This species lacks external ears entirely and is blind, its eyes covered by skin. Its nostrils are located behind a nosepad that is closed by flaps to keep out water. The sides of the feet have small scales, and the digits are fringed with stiff hairs; all four feet are webbed. Fringes and webbing expand the surface area of the feet for pushing through the water. The palms have large disklike pads that enhance agility on wet, slippery surfaces. Along the tail are four rows of fringes that coalesce toward the tip into a rudderlike shape. The elegant water shrew weighs up to 45 grams (1.6 ounces), with a body 10 to 14 cm (4 to 5.5 inches) long and a tail nearly as long as the body.

      Two of the 72 species in the genus Sorex are water shrews. The North American water shrew (S. palustris) is found throughout much of the western United States and Canada, from the plains to the mountains. It is the smallest and least specialized species of water shrew, weighing up to 18 grams, with a body 6 to 9 cm long and a slightly shorter tail. It forages on land and enters water to seek food and escape predators. It can remain underwater for 45 seconds or more at a time and is able to skitter across the surface supported by air bubbles trapped in the feet and toe fringes. Half of its diet consists of aquatic insects, the other half of terrestrial insects, earthworms, snails, and slugs as well as vegetation, mice, fish, and salamanders.

      In addition to the North American and elegant water shrews, there are several species of Oriental water shrews (genus Chimarrogale) and three species of Old World water shrews (genus Neomys). All are classified in the family Soricidae of the order Soricimorpha, which belongs to a larger group of mammals referred to as insectivores (insectivore).

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Universalium. 2010.

Look at other dictionaries:

  • Water shrew — may refer to one of several species of aquatic red toothed shrews: *Genus Chimarrogale (Asiatic water shrews) **Malayan Water Shrew ( C. hantu ) **Himalayan Water Shrew ( C. himalayica ) **Sunda Water Shrew ( C. phaeura ) **Japanese Water Shrew ( …   Wikipedia

  • Water shrew — Wa ter shrew (Zo[ o]l.) Any one of several species of shrews having fringed feet and capable of swimming actively. The two common European species ({Crossopus fodiens}, and {Crossopus ciliatus}) are the best known. The most common American water… …   The Collaborative International Dictionary of English

  • water shrew — vandeninis kirstukas statusas T sritis zoologija | vardynas taksono rangas rūšis atitikmenys: lot. Neomys fodiens angl. British water shrew; Eurasian water shrew; European water shrew; Old World water shrew; water shrew; white breasted water… …   Žinduolių pavadinimų žodynas

  • water shrew — noun Any of the small insectivores of the genus Neomys in the Soricidae family. There are three species, the Eurasian water shrew (also known as European water shrew) Neomys fodiens, the Mediterranean water shrew Neomys anomalus and the… …   Wiktionary

  • water shrew — noun any of several small semiaquatic shrews usually living near swift flowing streams • Hypernyms: ↑shrew, ↑shrewmouse • Hyponyms: ↑American water shrew, ↑Sorex palustris, ↑European water shrew, ↑Neomys fodiens, ↑ …   Useful english dictionary

  • water shrew — pelkinis kirstukas statusas T sritis zoologija | vardynas taksono rangas rūšis atitikmenys: lot. Sorex palustris angl. American water shrew; northern water shrew; water shrew vok. nordische Wasserspitzmaus rus. болотная бурозубка; водяная… …   Žinduolių pavadinimų žodynas

  • water shrew — pelkinis tenrekas statusas T sritis zoologija | vardynas taksono rangas rūšis atitikmenys: lot. Limnogale mergulus angl. aquatic tenrec; marsh tenrec; water shrew; web footed tenrec vok. Wassertanrek rus. болотный тенрек; водяной тенрек;… …   Žinduolių pavadinimų žodynas

  • water shrew — /ˈwɔtə ʃru/ (say wawtuh shrooh) noun either of two small aquatic shrews of the genus Neomys, inhabiting Europe and parts of Asia …   Australian English dictionary

  • American Water Shrew — American Water Shrew[1] Conservation status …   Wikipedia

  • Eurasian Water Shrew — Eurasian Water Shrew[1] Conservation status Least Concer …   Wikipedia

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