Gray short-tailed opossum [1] | |
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Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Infraclass: | Marsupialia |
Order: | Didelphimorphia |
Family: | Didelphidae |
Genus: | Monodelphis |
Species: | M. domestica |
Binomial name | |
Monodelphis domestica (Wagner, 1842) | |
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Gray short-tailed opossum range | |
Synonyms | |
Monodelphis domesticus |
The gray short-tailed opossum (Monodelphis domestica) is a small South American member of the family Didelphidae. Unlike most other marsupials, the gray short-tailed opossum does not have a true pouch. The scientific name Monodelphis is derived from Greek and means "single womb" (referring to the lack of a pouch) and the Latin word domestica which means "domestic" (chosen because of the species' habit of entering human dwellings). [3] It was the first marsupial to have its genome sequenced. The gray short-tailed opossum is used as a research model in science, [4] and is also frequently found in the exotic pet trade. It is also known as the Brazilian opossum, rainforest opossum and in a research setting the laboratory opossum.
Gray short-tailed opossums are relatively small animals, with a superficial resemblance to voles. In the wild they have head-body length of 12 to 18 cm (4.7 to 7.1 in) and weigh 58 to 95 grams (2.0 to 3.4 oz); males are larger than females. [5] However, individuals kept in captivity are typically much larger, with males weighing up to 150 grams (5.3 oz). [6] As the common name implies, the tail is proportionately shorter than in some other opossum species, ranging from 5 to 9 centimetres (2.0 to 3.5 in). [5] Their tails are only semi-prehensile, unlike the fully prehensile tail characteristic of the North American opossum. [3]
The fur is greyish brown over almost the entire body, although fading to a paler shade on the underparts, and with near-white fur on the feet. Only the base of the tail has fur, the remainder being almost entirely hairless. [5] The claws are well-developed and curved in shape, and the paws have small pads marked with fine dermal ridges. [7] Unlike many other marsupials, females do not have a pouch. They typically possess thirteen teats, [8] which can be retracted into the body by muscles at their base. [5]
The gray short-tailed opossum is found generally south of the Amazon River, in southern, central, and western Brazil. It is also found in eastern Bolivia, northern Paraguay, and in Formosa Province in northern Argentina. [2] It inhabits rainforest environments, scrubland, and agricultural land, and often enters man-made structures, such as houses. [5] There are no recognised subspecies.
Gray short-tailed opossums eat rodents, frogs, reptiles, and invertebrates, as well as some fruit. They hunt primarily by scent, poking their snout into vegetation in search of prey or dead animals to scavenge. Once they find living prey, they pounce onto it, holding it down with their forefeet while delivering a killing strike, often to the base of the neck, with their sharp teeth. They can successfully take prey up to their own size. [5]
They are nocturnal, being most active in the first three hours after dusk. Although they may occasionally shelter in natural crevices in the rock, they normally spend the day in concealed nests constructed of leaves, bark, and other available materials. The nests of females are more complex and tightly woven than those of males. They are solitary, coming together only to mate, and with each individual occupying a home range of 1,200 to 1,800 m2 (13,000 to 19,000 sq ft), flagged with scent marks. The approach of another member of the species is commonly met with hissing and screeching, which may escalate to defensive strikes launched while the animal is standing on its hind legs. [5]
The opossums breed year round when the climate is suitable, being able to raise up to six litters of six to eleven young each during a good year. Females only come into oestrus when exposed to male pheromones, with ovulation being induced only by physical contact with the male. [9] Gestation lasts fourteen days, after which the young attach to a teat, where they remain for the next two weeks. Like all marsupials, the young are born undeveloped; in this species they are just 1 centimetre (0.39 in) in length and weigh 0.1 grams (0.0035 oz) at birth. [10] The young grow hair at around three weeks, open their eyes about a week later, [5] and are weaned at eight weeks [11]
Gray short-tailed opossums are sexually mature at five to six months of age, and live for up to forty-nine months in captivity. [5]
The gray short-tailed opossum possesses several features that make it an ideal research model, particularly in studies of marsupials, as well as the immunological and developmental research on mammalian systems. It breeds relatively easily in laboratory settings, and neonates are exposed and can be readily accessed because, unlike other marsupial species, female opossums lack a pouch: neonates simply cling to the teats. Opossums are born at a stage that is approximately equivalent to 13- to 15-day-old fetal rats or 40-day-old human embryos. Like other marsupials, the inadequacies of the neonate's immune system function make it an ideal model for both transplant and cancer research, as well as general investigations into immune system development and its similarities to other eutherian mammals. [12] [13] Its genome was sequenced and a working draft published in May 2007: [14] the decoding work, directed by MIT and Harvard, reveals the opossum to have between 18,000 and 20,000 protein-coding genes. The full genome sequence and annotation can be found on the Ensembl Genome Browser. [15]
Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are primarily found in Australasia, Wallacea, and the Americas. One of the defining features of marsupials is their unique reproductive strategy, where the young are born in a relatively undeveloped state and then nurtured within a pouch.
The Virginia opossum, also known as the North American opossum, is the only opossum living north of Mexico, its range extending south into Central America. It is the northernmost marsupial in the world. In the United States and Canada, it is typically called a possum. It is a solitary nocturnal animal about the size of a domestic cat, and a successful opportunist.
Opossums are members of the marsupial order Didelphimorphia endemic to the Americas. The largest order of marsupials in the Western Hemisphere, it comprises 126 species in 18 genera. Opossums originated in South America and entered North America in the Great American Interchange following the connection of North and South America.
Quolls are carnivorous marsupials native to Australia and New Guinea. They are primarily nocturnal and spend most of the day in a den. Of the six species of quoll, four are found in Australia and two in New Guinea. Another two species are known from fossil remains in Pliocene and Pleistocene deposits in Queensland. Genetic evidence indicates that quolls evolved around 15 million years ago in the Miocene, and that the ancestors of the six species had all diverged by around four million years ago. The six species vary in weight and size, from 300 g (11 oz) to 7 kg (15 lb). They have brown or black fur and pink noses. They are largely solitary, but come together for a few social interactions such as mating which occurs during the winter season. A female gives birth to up to 30 pups, but the number that can be raised to adulthood is limited by the number of teats (6–7). They have a life span of 1–5 years.
The water opossum, also locally known as the yapok, is a marsupial of the family Didelphidae. It is the only living member of its genus, Chironectes. This semiaquatic creature is found in and near freshwater streams and lakes from Mexico through Central and South America to Argentina and is the most aquatic living marsupial. It is also the only living marsupial in which both sexes have a pouch. The thylacine, commonly referred to as the Tasmanian tiger, also exhibited this trait, but it is now extinct.
Didelphis is a genus of New World marsupials. The six species in the genus Didelphis, commonly known as Large American opossums, are members of the opossum order, Didelphimorphia.
The pouch is a distinguishing feature of female marsupials, monotremes ; the name marsupial is derived from the Latin marsupium, meaning "pouch". This is due to the occurrence of epipubic bones, a pair of bones projecting forward from the pelvis. Marsupials give birth to a live but relatively undeveloped foetus called a joey. When the joey is born it crawls from inside the mother to the pouch. The pouch is a fold of skin with a single opening that covers the teats. Inside the pouch, the blind offspring attaches itself to one of the mother's teats and remains attached for as long as it takes to grow and develop to a juvenile stage.
The gray four-eyed opossum is an opossum species from Central and South America, ranging from southern Mexico to Peru, Bolivia and southwestern Brazil, at altitudes from sea level to 1600 m, but generally below 1,000 metres (3,300 ft). Its habitats include primary, secondary and disturbed forest. It is one of many opossum species in the order Didelphimorphia and the family Didelphidae.
The bare-tailed woolly opossum is an opossum from South America. It was first described by Swedish zoologist Carl Linnaeus in 1758. The bare-tailed woolly opossum is characterized by a gray head, brown to gray coat, orange to gray underside and a partially naked tail. It is nocturnal and solitary; there is hardly any social interaction except between mother and juveniles and in mating pairs. The opossum constructs nests in tree cavities, and its litter size ranges from one to seven. Gestation lasts 25 days, and the juveniles exit the pouch after three months; weaning occurs a month later. The bare-tailed woolly opossum inhabits subtropical forests, rainforests, secondary forests, and plantations; its range extends from northern Venezuela to northeastern and southcentral Brazil. The IUCN classifies this opossum as least concern.
Monodelphis is a genus of marsupials in the family Didelphidae, commonly referred to as short-tailed opossums. They are found throughout South America. As of January 2019, the most recently described species is M. vossi.
The northern red-sided opossum or the Guianan short-tailed opossum, Monodelphis brevicaudata, is an opossum species from South America. It is found in Bolivia, Brazil. French Guiana, Guyana, Suriname and Venezuela.
The yellow-sided opossum is an opossum species from South America. It is found in Argentina, Brazil and Uruguay. They have grey or black fur on their dorsal side with yellowish fur on the lateral side that continues down to the feet. They are the most mysterious of all the Monodelphis that is found specifically in the Pampean region or Pampa of Argentina. It is suspected to be a once-in-a-lifetime breeder as seen in a three-year observational study of one population in the marshy grasslands of the Pampean region. Maintaining their native grasslands is important for them to keep a stable population. They show sexual dimorphism in overall size: adult males are typically 100-150 g whereas adult females are 30-70 g.
The pygmy short-tailed opossum, scientifically named Monodelphis kunsi, is an opossum species from South America. M. kunsi is a marsupial from the family Didelphidae of the order Didelphimorphia. Although it is a marsupial, it lacks the characteristic pouch that is often associated with this order. It is found in Argentina, Bolivia, Brazil and Paraguay. M. kunsi is considered a smaller species within the family Didelphidae, which is why it is named a pygmy opossum. The young are referred to as 'joeys'. The females are referred to as 'Jill,' and the males 'jack'. It was thought to have been endangered in 2001, but has since been moved to least concern by the International Union for Conservation of Nature.
The southern red-sided opossum is an opossum species from South America. It is found in Argentina, Brazil and Paraguay.
The grayish or gray mouse opossum is a diminutive species of opossum in the family Didelphidae, endemic to Mexico. It is the sole species of its monotypic genus, Tlacuatzin.
The elegant fat-tailed mouse opossum, also known as the Chilean mouse opossum, is an opossum from central Chile. The type species of Thylamys, it was first described by English naturalist George Robert Waterhouse in 1839. This medium-sized opossum is characterized by black rings around the eyes, white limbs, gray to light brown coat, lighter flanks and underbelly and a thick 12.7–14.6 centimetres (5.0–5.7 in) long tail covered with hairs. It is crepuscular and lives in nests in tree hollows or under rocks and roots. This opossum feeds mainly on arthropods and larvae apart from fruits. Litter size is typically between 11 and 13. The elegant fat-tailed opossum can occur in a variety of habitats – from cloud forests to chaparrals. The IUCN classifies the opossum as least concern.
The white-bellied fat-tailed mouse opossum is a species of opossum in the family Didelphidae. It is found in Argentina, Bolivia, Chile and Peru.
The Didelphinae are a subfamily of opossums consisting of 15 genera and 123 species. Specimens have been collected throughout the Americas, but are predominant in South and Central America.