Monodelphis is a genus of marsupials in the family Didelphidae, commonly referred to as short-tailed opossums. They are found throughout South America., the most recently described species is M. vossi.
Species limits are based on fur coloration with additional details coming from differences in the skull and teeth.[2]
Short-tailed opossums show a rich repertoire of stereotyped behaviors.[3] Postures, locomotion, and grooming behaviours are similar to those of other didelphids. They also can carry nest materials using their short prehensile tails.
Short-tailed opossums show specialized behaviors for dealing with challenging prey. For example, attacks and initial consumption of large insects are initially directed to the insect's head, hairy caterpillars are scratched to get rid of the urticating hairs, and mice are attacked using a throat clamp technique.
Short-tailed opossums have been found to use nuzzling in chemosensory and exploratory behavior for recognizing individuals of the same species. In Monodelphis domestica, nuzzling and snout-rubbing transforms odor from dry components like glandular secretions, feces, and urine, into moist naso-oral secretions that reach the vomeronasal organ to be processed chemically. Typically, this behavior is used to recognize individual familiar or new scents from the same species, with males typically being drawn to more novel scents from the same species.[4]
M. sorex and M. rubida are considered to be endangered.
The genus Monodelphis is marsupial; they are born under-developed and then mature further in the mother's pouch. In Monodelphis, the young first come off the teat in 12 days, whereas this occurs at 48 days in the related genus Didelphis. Most of the events in this process occur about 2–4 weeks later in Didelphis than in Monodelphis. This may be related to the shorter longevity of the species of Monodelphis compared to other marsupials who nurse for a longer period.[5] M. dimidiata is unusual in that it is a semelparous species, something rarely seen in mammals, being found predominantly in smaller didelphids and dasyurids.