Monodelphis

Monodelphis is a genus of small marsupials in the family Didelphidae, commonly known as short-tailed opossums. They are native to South America, with several species occupying tropical and subtropical forests, savannas, and grasslands from the Amazon basin to the Southern Cone. The genus includes numerous species; the best known is Monodelphis domestica, the gray short-tailed opossum, widely used as a laboratory model in developmental biology and neuroscience.

Physical characteristics and ecology: Monodelphis are small, with compact bodies and comparatively short tails. They are primarily nocturnal and terrestrial, though some species may forage in low vegetation. Their dentition and morphology reflect an omnivorous, opportunistic diet that includes insects, fruit, seeds, and occasionally small vertebrates. They are generally insectivorous and opportunistic feeders, foraging on the forest floor and leaf litter.

Behavior and reproduction: they are solitary outside the breeding season and have home ranges that vary by species and habitat. As marsupials, they give birth to underdeveloped young that complete development after birth, typically nursing on the mother's nipples. Reproductive traits such as litter size, gestation length, and the presence or absence of a true pouch vary among species.

Conservation and research: habitat loss and fragmentation threaten some species, though the genus has a broad distribution overall. Monodelphis domestica stands out for its fully sequenced genome, making it a valuable model in biomedical and developmental research, including studies of neurobiology and aging.