Mammals

Shrews are a highly successful group of insectivores, comprising the third most speciose mammal family (Soricidae). They occur throughout most of the world, with the exception of Australasia and much of South America. They are often portrayed as “primitive” animals; indeed, the earliest mammals are often portrayed as shrew-like. However, soricids are a relatively modern group. The earliest shrew fossils have been found in North America from the middle Eocene (45 million years ago). They are known from Asia and Europe from the early Oligocene (34 million years ago), and in Africa from the middle Miocene (14 million years ago). The Soricidae is divided into two sub-families: the Crocidurinae (white-toothed shrews) and the Soricinae (red-toothed shrews). Red-toothed shrews are so-called because their teeth have a reddish appearance because of a deposition of iron in the outer layer of enamel, which may increase resistance to wear. The genus Chimarrogale belongs to the Soricinae, and is thought to have diverged from other shrews during the Miocene (7-26 million years ago). The taxonomic status of the Sumatran water shrew is uncertain. Some authorities consider it to be a full species, while others consider it to be a subspecies of Chimarrogale phaeura (the Bornean water shrew).

Head and body length: 80-130 mm
Tail length: 60-101 mm

This relatively large shrew has a coat of short dense fur which is a uniform sooty grey colour above, interspersed with longer white-tipped hairs, and dull-brown below. The tail is dark brown. Like other shrews the Sumatran water shrew has a long snout, small eyes and ears, short legs and a long tail in relation to its body length. The species has a number of modifications to a semi-aquatic lifestyle. Its fur is relatively waterproof and there is a flap of skin which seals the ear openings when submerged. The feet are fringed with stiff hairs which help to propel the animal through the water.