The brown four-eyed opossum (Metachirus nudicaudatus) is a pouchless marsupial[3] of the family Didelphidae. It is found in different forested habitats of Central and South America,[2] from Nicaragua to Brazil and northern Argentina,[1] including southeastern Colombia, Paraguay and eastern Peru and Bolivia, at elevations from sea level to 1500 m.[2] It is the only recognized species in the genus Metachirus,[1] but molecular phylogenetics studies suggest that it should probably be split into several species.[2] Population densities are usually low, and it is uncommon in parts of Central America.[2] A density of 25.6/km2 was reported near Manaus, Brazil.[3] Its karyotype has 2n = 14 and FN = 24.[3]
It is a nocturnal, solitary,[2] strongly terrestrial and omnivorous animal, feeding on fruits, small vertebrates and invertebrates.[3]
The brown four-eyed opossum builds nests made of leaves and twigs in tree branches or under rocks and logs.[4] It is seasonally polyestrous and the litter size varies from one to nine.[3]
The white spot over each eye inspired the common name of "four-eyed opossum". Its scaly tail is longer than its body.[3]
The opossum appears to be mostly insectivorous, though also consumes some types of fruit seeds, small vertebrate creatures like birds and reptiles and invertebrates like crayfish and snails.[5] The brown four-eyed opossum is a host of the Acanthocephalan intestinal parasite Gigantorhynchus ortizi.[6]