The spotted-necked otter is usually chocolate to reddish brown and marked with creamy or white blotches over the chest and throat.

Females have two pairs of teats, and while males have a large scrotum, the penis is hidden beneath the skin, to reduce drag while swimming.

[3] The spotted-necked otter is very vocal, uttering high, thin whistles and rapid, shrill chatters.

[4] They normally hunt alone, except when mothers are training their young, and are not territorial, sheltering through the night in short burrows, rock crevices, or patches of dense vegetation.

[6] The spotted-necked otter is diurnal and appears to hunt entirely by sight using short dives of less than 20 seconds each in clear water with good visibility.