Aonyx cinereus

The Asian small-clawed otter (Amblonyx cinerea), also known as the oriental small-clawed otter or simply small-clawed otter, is a semiaquatic mammal native to South and Southeast Asia. It is a member of the otter subfamily (Lutrinae) of the weasel family (Mustelidae), and is the smallest otter species in the world. Its paws are a distinctive feature; its claws do not extend beyond the fleshy end pads of its partially webbed fingers and toes. This gives it a high degree of manual dexterity so that it can use its paws to feed on molluscs, crabs and other small aquatic animals. The Asian small-clawed otter inhabits mangrove swamps and freshwater wetlands in South and Southeast Asia. It lives in extended family groups with only the alpha pair breeding; offspring from previous years help to raise the young. Due to ongoing habitat loss, pollution, and hunting in some areas, it is listed as Vulnerable on the IUCN Red List. This species was originally described as the only member of the genus Amblonyx, but was transferred to the genus Aonyx after mitochondrial DNA analysis. However, further studies have shown that this species is more closely related to the genus Lutrogale than to Aonyx, which means the genus Amblonyx should be retained. A synonym for the Asian small-clawed otter is Aonyx cinereus. Asian small-clawed otters are the smallest extant otter species. The overall length can range from 70 to 100 cm (28 to 39 in), of which about 30 cm (12 in) is the tail. Weight can range from 1 to 5.4 kg (2.2 to 11.9 lb). Its body is slender, streamlined and serpentine, and is flexible enough to allow grooming of almost all the body. Dark, grayish-brown fur covers most of the dorsal surface with a lighter cream coloration on the ventral surface, especially on the face and neck. The fur has relatively short hairs less than 2.5 cm in length, and it is fine, dense and velvety. Otters have two types of fur: long, stout guard hairs and a short, fine undercoat. Asian small-clawed otters have flattened heads and short, thick necks; eyes are located toward the front of the head. The ears are small and rounded and have a valve-like structure that enables them to be closed when swimming underwater. Nose pads are dusky or pinkish in color. The muzzle has vibrissae on either side. These are sensitive to touch and to underwater vibrations, and are important in detecting the movements of prey. Similar to other otters, Asian small-clawed otters have relatively short legs, which are used to swim, walk, groom and manipulate prey. Feet are very narrow and only webbed to the last joint, a feature which distinguishes the Asian small-clawed otter from all other species of otter. These partially webbed paws give them an excellent sense of touch and coordination, providing them with more dexterity than other otters with full webbing. Unlike other otters, they catch their prey with their paws instead of with their mouth. Their small, blunt, peg-like claws are extremely reduced and rarely extend past the tips of the digits. The Asian small-clawed otter's tail is long, about one-third of its total body length. The tail is thick at the base, muscular, flexible, and tapers to a point. Subcutaneous and scent glands are located at the base of the tail. The tail is used for propulsion when swimming at high speed, to steer when swimming slowly and for balance when standing upright on hind legs. The Asian small-clawed otter ranges in coastal regions from southern India to Southeast Asia including the islands of Sumatra, Java, Borneo and Palawan. It inhabits freshwater wetland systems such as swamps, meandering rivers, mangroves and tidal pools as well as irrigated rice fields. It prefers pond areas and rice fields over rivers with bare banks, but dislikes bare and open areas that do not offer any shelter. It wanders between patches of reeds and river debris where many crab species are likely to be found. In the riverine systems it chooses areas with low vegetation, and dugs nesting burrows into muddy banks. It spends most of its time on land unlike most other otters.