Adult males are roughly one-and-a-half times larger than the females, and can measure up to 64 centimetres (2 ft) in height, and weigh up to 8 kilograms (18 lb).

Like other macaques it possesses cheek pouches in which it can store food temporarily, and transport it away from the foraging site to be eaten in shelter and safety.

Apart from these populations in the wild, only a single group (as of 2002) of some 17 individuals is held in an Indian zoo for captivity breeding and research purposes.

As with other primates whose habitats overlap with or are encroached upon by human settlement activities, there is some risk of zoonotic disease transference to individuals who come into close contact with them.

In common with other crab-eating macaques it turns to other sources of food—typically in the dry and early rainy tropical seasons—when the preferred fruits are unavailable.

This alternate diet includes young leaves, insects, flowers, seeds, and bark; it is also known to eat small crabs, frogs and other creatures taken from the shorelines and mangroves when foraging in these environments.

[1] The Wildlife Institute of India however registered their status in 2002 as critically endangered, reflecting also their concerns that conservation efforts with regards to a defined captive breeding programme were deficient.