Appearance and Anatomy of the Hairy-Nosed Otter

The information below comes from Harris (1968) and Wright et al (2008), All pictures are courtesy of Furget-Me-Not


Sideview of the hairy-nosed otter, showing the long, tapered tail, strong, well-clawed feet and distinctive white lip A fish-eating otter, around the same size as a Eurasian Otter, living in flooded tropical forests in south east Asia, this animal was thought to be extinct but was rediscovered at four locations since 1998. These long, snaky otters, which are about the same size as a Eurasian otter, really do have hairy noses!


There are very few measurements available, but this appears to be the range for adult otters. Populations in different areas seem to differ in size - in the historical literature, Malaysian otters were considered larger than Sumatran ones. 

Sex Total Length Tail Weight
Male 95 - 133 cm
(37 - 52")
41 - 51 cm
(16 - 20")
5 -8 kg
(11 - 17lb)

In specimens from Thailand, the female has generally been found to be smaller than the male.

Head and Teeth

Head of a hairy-nosed otter showing the strong canines, tiny incisors, nairy nose and white lip. Close-up of face of otter, showing hairy nose, and bare skin on the upper edge of the nostrils.  The white 'moustache' is also shown clearlyThe skull of this species is more elongated than in other similar otters, with a shorter relative distance from eye to nose, although this is not obvious in life.

The most important characteristic for identification is the hairy nose.  The rhinarium is entirely covered in short, dark, dense fur and even on old museum specimens where the hair may have been lost or damaged, the underlying skin shows tiny pits rather than the smooth leathery textrue of other otter noses.  The only bare skin on this otter's nose is teh upper edge of the nostrils.

The teeth are sturdy standard otter teeth. The dental formula is

I 3/3 C 1/1 P 4/3 M 1/2 = 36



This species is the usual long, slender otter shape, but in life, move in a more serpentine manner than other otters - they seem to be particularly flexible and agile.  Very little detailed anatomy is known, apart from an observation by Cantor (1846) that the alimentary canal was 2.7m (9') long with no caecum, which is odd seeing as the equivalent length for the Eurasian Otter (Lutra lutra) is about half as long. Like other otters, the kidneys are multilobed like cattle, and not smooth like pigs or lambs.


The tail, which is about a third of the total length of the animal, is the usual tapered otter tail, rounded in cross-section but slightly flattened underneath.

Legs and Paws

This otter has fully-webbed paws, with short, fine hairs on the upper surface, and naked beneath. The claws are strong and well developed.  Kanchanasaka (2001) took plaster casts of the footprints of this species, and found them hard to distinguish from those of the Eurasian otter (Lutra lutra) which also lives in the same habitat, although measurements showed them to be a little larger. The smooth-coated otter (Lutrogale perspicillata) lives in the same area, but its tracks are larger and more oval. 


The guard hairs are 12 - 14mm long and the underfur is 7 - 8mm long. The main colour of the hairy-nosed otter is usually dark chocolate brown, with the underside almost the same colour.  The upper lip, chin and front part of the throat is white to yellow; the white 'moustache' is a good diagnostic feature.  Some animals may be more chestnut in colour, but this may differ by location.  The underfur is very pale.

Hairy-Nosed Otter