Characteristics: Species measuring about 22cm in length and with a tail measuring 30cm. It has a tricolor, woolly, and soft coat that ranges from brownish black to whitish gray in color, webbed feet and a perfect, large pouch typical of marsupials.

Distribution: Southern Mexico to Southern Peru, Central Bolivia, Southern Paraguay and Brazil, and Northeastern Argentina.

Habitat: Forests, always near water.

Habits: A semi-aquatic nocturnal species, this opossum does not see well during the day; it may make nests to rest in and prefers quiet, dark places. It swims with its head and ears above the water and its body submerged.

Diet: It is essentially carnivorous and piscivorous, feeding on small fish, crustaceans and other aquatic animals; it may also consume some aquatic plants and fruits.

Breeding: The most common number of offspring per breeding period is 2 or 3, which the female keeps protected in its pouch ("stock") while swimming.

In the UFRA area: Species considered rare within these farms because it was only spotted once, in wetlands where there were herbaceous plants.