Heard last night on KQED, a BBC Science program, “Pyrenean desman: On the trail of Europe’s weirdest beast” by Rebecca Morelle. Odd creatures indeed, with a misleading name.
From Wikipedia on the desmans in general:
The desmans or tribe Desmanini are one of several tribes of the mole family Talpidae.
This tribe consists of two species of semiaquatic insectivores found in Europe; one in Russia and the other in the Pyrenees. Both species are considered to be vulnerable. They have webbed paws and their front paws are not well adapted for digging.
The species are (in the genus Galemys) the Pyrenean desman (G. pyrenaicus) and (in the genus Desmana) the Russian desman (D. moschata). On the former (from the Arkive site, which has links to references):
Named after the place of its home, the Pyrenean desman is a small aquatic insectivore closely related to moles, also known as the Iberian desman. This adept swimmer has many adaptations to its aquatic habitat, including an elongated head and body with a long tail, webbed, paddle-like hindfeet, and the ability to close both ears and nostrils to prevent water getting in. In contrast to moles, which have powerful digging front legs, desmans have powerful hind legs that are longer than the forefeet to help propel them through the water. The tail is also slightly flattened vertically, acting as a rudder and helping to steer and direct the animal as it swims. A double layer of fine dark greyish-brown fur includes a dense waterproof underfur and oily guard hairs. The eyes are tiny and eyesight is poor, but the long, black, almost hairless snout is highly sensitive and used to locate prey.
A 1927 drawing of the Russian desman:
Now, the name. From OED2, the etymology:
In French and German desman, < Swedish desman-råtta musk-rat, < desman (Danish desmer, Icelandic des-) musk.
According to the OED, the Russian desman is known as the musk-shrew or musk-rat, but these creatures are not shrews, rats, or muskrats, but are most closely related to moles (which, indeed, they resemble, though they are semiaquatic rather than subterranean and have highly developed hindlimbs rather than forelimbs).
The BBC Science story is an entertaining lightweight piece, focusing especially on the difficulties of studying these reclusive nocturnal creatures.