The Brazilian marsh rat lives in wetlands and has webbed hind feet. It eats plant material and is adapted for swimming.
Its back is cinnamon, its sides are orange, and its underside is pale orange. The hind feet have webbing between the toes.
It lives in marshes, swamps, grasslands, and other open wetlands, where it eats leaves and other plant material. Trapping records suggest it is nocturnal, and it is adapted for swimming.
An extinction-risk assessment has not been added yet.