Asian short-clawed otter (Aonyx cinerea)
|Also known as:||Oriental small-clawed otter, small-clawed otter|
|Synonyms:||Amblonyx cinereus, Aonyx cinereus|
|Spanish:||Nutria Cenicienta, Nutria Inerme Asiatica|
|Size||Head-body length: 45 – 61 cm (2)|
Tail length: 25 – 35 cm (2)
|Weight||1 – 5kg (2)|
Classified as Vulnerable (VU) on the IUCN Red List (1) and listed on Appendix II of CITES (3).
This charismatic mammal, equally at home in the water and on land, is the smallest of the world’s otters (4). As well as its size, the Asian short-clawed otter can be distinguished from other otters by its small claws (5), after which it is named, and the incomplete webbing between digits. These tiny claws, which do not protrude beyond the ends of the fingers (2), enhance the manual dexterity of this otter as it handles prey (5). The Asian short-clawed otter typically has brown fur with a paler underside, although cream-coloured individuals have also been known (5) (6). The edges of the upper lip, chin, throat, sides of neck and face are generally greyish-white (5). Like other otters, the Asian short-clawed otter has a small head, short legs and flattened tail, creating a streamlined silhouette that can move easily through the water (5) (7).
The Asian short-clawed otter has a large distribution, ranging from north-western and south-western India, through southern China (including Hainan) and the Malay Peninsula, to Sumatra, Java, Borneo and the Riau Archipelago (Indonesia), and Palawan Island in the Philippines (2).
A truly amphibious animal, the Asian short-clawed otter can be found in, and around, rivers, creeks, estuaries, hill streams, marshes, coastal wetlands (2), mangroves and rice fields (6), often close to human activity (5). It prefers areas of shallow water, where there is both abundant food and sufficient vegetation (4), and can be found from sea level up to 2,000 metres (5).
The Asian short-clawed otter is a sociable animal, living in loose family groups of up to 12 individuals (2). Within each group is an adult monogamous pair, with both parents contributing to the raising of their offspring (5). The female gives birth to up to two litters each year (2), each containing up to seven young but often just containing one or two. The young are born after a gestation period of 60 to 64 days (2), into a nest of grass that the female has built two weeks prior (5). The young otters do not open their eyes until 40 days old. At seven to nine weeks of age they take their first swim and, shortly after, they eat solid food (2) (8).
The diet of the Asian short-clawed otter consists primarily of crabs, other crustaceans, molluscs and fish (2), although frogs, small mammals, snakes and insects are also eaten (6). With their sensitive and dexterous front paws, they dig around in the mud or under stones to find their prey (2). With their large back teeth, the Asian short-clawed otter can crush the shells of crabs and molluscs, or they have been known to leave these creatures out in the sun once they have been dug up, where the heat causes the shells to open up (5). In areas of rice fields, the Asian short-clawed otter may serve a valuable function to farmers as it preys on the crabs found in the paddies (6).
When not searching for food, this playful otter may be found along the grassy or sandy banks of rivers, resting or grooming (5). It interacts with other members of the family group using a vocabulary of at least 12 calls (2), including greeting, mating and alarm calls (5). In Malaysia at night, their chirps are often heard as they move through rice fields (6).
The most significant threat to the Asian short-clawed otter is the destruction of habitat (1). Throughout Asia, deforestation is resulting in the loss of hill streams, peat swamp forests are drained for agriculture, and mangroves are being converted for aquaculture (1) (4). Aquaculture projects are a particular problem, as they bring otters in closer contact with humans who view them as pests. Few areas can afford the fences needed to keep otters from killing the fish or prawn stocks; instead, the otters are killed (6). The hunting of otters for their pelts and organs, which may be used in traditional medicines, is also a very significant threat to this species (9).
Further threats to this species include a reduction in their prey as a result of overexploitation by humans, and pollution, which may also affect prey abundance, as well as the otter directly (1) (4). Tea and coffee plantations in India, and other forms of intensive agriculture elsewhere, not only often destroy the otter’s natural habitat, but result in the surrounding streams and rivers being polluted by pesticides (1) (4).
Limited conservation measures are in place for the Asian short-clawed otter. There is some national legal protection in place for this species (4), for example, in Malaysia and Singapore, all otters are totally protected (10), but local habitat protection needs to be established (4). In 1983, the American Association of Zoological Parks and Aquariums established a species survival plan to encourage more research on the captive breeding of this species (5). Many zoos in the world keep this species (10), creating the opportunity for scientists to gain further knowledge about this fascinating mammal, which can then be used to assist their conservation in the wild.
One of the key organisations involved in the conservation of the Asian short-clawed otter is the IUCN Otter Specialist Group, which has developed a network of biologists across Asia that are conducting field surveys and popularising this species’ conservation. Nevertheless, concerted conservation effort—involving policy, research and habitat-based action—is required if the long-term survival of the Asian short-clawed otter is to be assured (1).
For further information on the conservation of the Asian short-clawed otter, see:
IUCN Otter Specialist Group:
Authenticated (01/07/2010) by Daniel Willcox, Field Research Advisor, Carnivore and Pangolin Conservation Program (CPCP), Vietnam.
- Amphibious: capable of living both on land and in water.
- Crustaceans: diverse group of arthropods (a phylum of animals with jointed limbs and a hard chitinous exoskeleton) characterised by the possession of two pairs of antennae, one pair of mandibles (parts of the mouthparts used for handling and processing food) and two pairs of maxillae (appendages used in eating, which are located behind the mandibles). Includes crabs, lobsters, shrimps, slaters, woodlice and barnacles.
- Gestation: the state of being pregnant; the period from conception to birth.
- Molluscs: a diverse group of invertebrates, mainly marine, that have one or all of the following; a horny, toothed ribbon in the mouth (the radula), a shell covering the upper surface of the body, and a mantle or mantle cavity with a type of gill. Includes snails, slugs, shellfish, octopuses and squid.
- Monogamous: having only one mate during a breeding season, or throughout the breeding life of a pair.
IUCN Red List (January, 2009)
- Nowak, R.M. (1999) Walker's Mammals of the World. Johns Hopkins University Press, Baltimore, Maryland.
CITES (June, 2008)
IUCN Otter Specialist Group (August, 2008)
- Larivière, S. (2003) Amblonyx cinereus. Mammalian Species, 720: 1-5.
- Foster-Turley, P. (1992) Conservation Aspects of the Ecology of Asian Small-Clawed and Smooth Otters on the Malay Peninsula. IUCN Otter Specialist Group Bulletin, 7: 26-29.
- Macdonald, D.W. (2006) The Encyclopedia of Mammals. Oxford University Press, Oxford.
- Wilson, D.E. and Reeder, M.D. (2005) Mammal Species of the World. A Taxonomic and Geographic Reference. The John Hopkins University Press, Baltimore, Maryland.
- Willcox, D. (2010) Pers. comm.
- Sivasothi, N. and Burhanuddin Hj, M.N. (1994) A review of otters (Carnivora: Mustelidae: Lutrinae) in Malaysia and Singapore. Hydrobiologia, 285: 151-170.