Oryzomys is a genus of semiaquatic rodents in the tribe Oryzomyini living in southern North America and far northern South America. It includes eight species, two of which—the marsh rice rat (O. palustris) of the United States and O. couesi of Mexico and Central America—are widespread; the six others have more restricted distributions.

The marsh rice rat (Oryzomys palustris) is a semiaquatic North American rodent in the family Cricetidae. It usually occurs in wetland habitats, such as swamps and salt marshes.

Oryzomyini is a tribe of rodents in the subfamily Sigmodontinae of the family Cricetidae. It includes about 120 species in about thirty genera, [1] distributed from the eastern United States to the southernmost parts of South America, including many offshore islands.

Oryzomys is a genus of semiaquatic rodents in the tribe Oryzomyini living in southern North America and far northern South America. It includes eight species, two of which—the marsh rice rat (O. palustris) of the United States and O. couesi of Mexico and Central America—are widespread; the six others have more restricted distributions.

The marsh rice rat (Oryzomys palustris) is a semiaquatic North American rodent in the family Cricetidae. It usually occurs in wetland habitats, such as swamps and salt marshes.

rice rat, (genus Oryzomys), any of 36 nocturnal species of small rodents found from the United States southward through tropical and portions of subtropical South America. Rice rats have soft fur, with tawny to grayish brown upperparts and paler underparts.

Working with others to conserve, protect and enhance fish, wildlife, plants and their habitats for the continuing benefit of the American people.

Oryzomys gorgasi is a medium-sized, brownish species with large, semiaquatically specialized feet. It differs from other Oryzomys species in several features of its skull. Its diet includes crustaceans, insects, and plant material.

The most commonly used species in biomedical research is Oryzomys palustris, sometimes known as the marsh rat (Edmonds and Stetson, 1995; Edmonds et al., 2003). The rice rat may be a reservoir host for Lyme disease (Levin et al., 1995).

Ory­zomys al­bigu­laris is a large rat-like ro­dent with a head and body length rang­ing be­tween 132 and 174 mm and an av­er­age mass of 61.9 g. It has a naked, non-peni­cil­lated tail that is usu­ally equal to or slightly shorter than its body length.