| Brazilian gracile opossum [1] | |
|---|---|
 | |
| Gracilinanus microtarsus | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Infraclass: | Marsupialia |
| Order: | Didelphimorphia |
| Family: | Didelphidae |
| Genus: | Gracilinanus |
| Species: | G. microtarsus |
| Binomial name | |
| Gracilinanus microtarsus (Wagner, 1842) | |
 | |
| Brazilian gracile opossum range | |
The Brazilian gracile opossum (Gracilinanus microtarsus) is a species of small opossum from Brazil.
Brazilian gracile opossums are relatively small opossums, with males ranging from 86 to 129 centimetres (34 to 51 in) and females from 81 to 116 centimetres (32 to 46 in) in snout-to-rump length. The tail is an additional several inches, and makes up between 30 and 50% of the animal’s total length. Males weigh 17 to 52 grams (0.60 to 1.83 oz) and females from 12 to 37 grams (0.42 to 1.31 oz). [3]
The gracile opossum’s coat comes in various colors and tones, including beige, sandy-or amber-tinted, with darker ears and extremities. Additionally, many individuals have fur that makes use of countershading, likely to avoid predators when in the trees. Much like whales, penguins, and numerous marine species, for example, countershading is the top half of an animal’s body being colored darker than the lighter underbelly, and possibly extending to the chin. Gracile opossums often display reddish, dark brown or grey over most of their body, with paler, cream-colored undersides. This helps them stay camouflaged from threats in the trees, both from above and below. The fur on the face is also relatively pale, with distinct rings of near-black fur around each eye.
The tail is very sensitive, prehensile, somewhat scaly, and does not store fat as it does in some related species. The hands and digits are somewhat monkey-like, for an arboreal lifestyle; being relatively long, they are equipped with small, efficient nails/claws.
The female typically has fifteen teats, although the exact number can vary; the majority are on the chest, with the remainder (including a single median teat) being on the abdomen. [4]
The Brazilian gracile opossum is found only in Brazil, being endemic to the south-eastern parts of the country, from Espirito Santo to Rio Grande do Sul. [4] It inhabits rainforests and partly deciduous forests scattered in the southern regions of the cerrado ecoregion, but, being able to forage successfully on the ground, is less affected by fragmentation of forest habitats than more purely arboreal animals. [5] It has also been found in artificial plantations.
There are no recognised subspecies.
Brazilian gracile opossums are arboreal and nocturnal, spending the day nesting in tree hollows. They are solitary animals, with each individual inhabiting a home range of anything from 0.03 to 0.32 hectares (0.074 to 0.791 acres), depending on habitat. Males tend to have larger home ranges than females, presumably because, being larger, they require more food. [4]
The species is insectivorous, and is an opportunistic forager, not specialising in any particular kind of insect. Individuals have also been reported to eat some spiders, snails, and even fruit (including passionfruit). Predators of Brazilian gracile opossums include ocelots, oncillas, crab-eating foxes, maned wolves and white-tailed hawks. [4]
Females come into estrus once a year, between August and September. Litters of up to twelve young are born during the wet season, when food is plentiful. The mother does not possess a pouch. They are weaned by three months of age, between November and December. The young are fully grown, with an adult set of teeth, by six months, reaching sexual maturity within a year of birth. Most Brazilian gracile opossums do not survive for much longer than a year, but some can reach two years of age. [6]
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.
The white-bellied woolly mouse opossum is a small pouchless marsupial of the family Didelphidae. It was formerly assigned to the genus Micoureus, which was made a subgenus of Marmosa in 2009. The specific epithet was given in honour of Constance Sladen, wife of the naturalist Percy Sladen. She funded the 1902 expedition which collected the type specimen.
The Chacoan pygmy opossum is a recently described genus and species of didelphimorph marsupial. The only species in Chacodelphys, C. formosa, was known until 2004 from only one specimen collected in 1920 in the Chaco of Formosa Province, Argentina. The species is gaining popularity as a pocket pet.
The bushy-tailed opossum is an opossum from South America. It was first described by English zoologist Oldfield Thomas in 1912. It is a medium-sized opossum characterized by a large, oval, dark ears, fawn to cinnamon coat with a buff to gray underside, grayish limbs, and a furry tail. Little is known of the behavior of the bushy-tailed opossum; less than 25 specimens are known. It appears to be arboreal (tree-living), nocturnal and solitary. The diet probably comprises insects, eggs and plant material. This opossum has been captured from heavy, humid, tropical forests; it has been reported from Bolivia, Brazil, Colombia, Ecuador and Peru. The IUCN classifies it as least concern.
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.
The brown-eared woolly opossum, also known as the western woolly opossum, is an opossum from South America. It was first described by German naturalist Ignaz von Olfers in 1818. The opossum is characterized by a brown to reddish brown coat and similarly colored limbs, yellow to orange underbelly, hairless, brown ears with a hint of pink, and a tail furred on the back for up to half of its length. The brown-eared woolly opossum is nocturnal, solitary and omnivorous. The IUCN lists it as least concern.
The black-shouldered opossum, also known as the white-eared opossum, is an opossum known from western Brazil and southeastern Peru. It was first described by Colin Campbell Sanborn, curator of Field Museum of Natural History, in 1951. The black-shouldered opossum is characterized by a gray coat, gray underbelly, and broad black stripes that extend from the forefeet, meet on the shoulders, run along the midline of the back and then split into parallel stripes that run down the hind feet. Little is known of the behavior of the black-shouldered opossum. It is nocturnal and arboreal. It is known to feed on fruits and rodents. The opossum inhabits humid forests. The IUCN classifies it as least concern.
The gray short-tailed opossum 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" and the Latin word domestica which means "domestic". It was the first marsupial to have its genome sequenced. The gray short-tailed opossum is used as a research model in science, 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.
The agile gracile opossum, is an opossum species from South America. It is found in Argentina, Bolivia, Brazil, Colombia, Peru, Paraguay, and Uruguay.
Marmosops is a genus of Neotropical opossums of the family Didelphidae. The genus was originally treated as a subgenus from the genus Marmosa rather than having their own classification. This was changed in 1989 by Gardner and Crieghton, who officially separated the group and made them their own genus. The mix-up between to genera Marmosa and Marmosops was common due to the similar appearances including size and other external features. However, the two groups differ significantly in their integument and in the arrangement of their skull and dentition. The dentition is similar in morphology between the two groups, with the exception of the deciduous lower third premolar varying from one genus to the next. The similarity between the two continues to cause the genus Marmosops to be frequently misidentified due to the lack of knowledge regarding the species along with the overlooked traits that help separate them from other opossums. The Marmosops are also commonly confused with the genus Gracilinanus, but this is quickly ruled out by a large number of differing characteristics. These differences include the arrangement of their digits, caudal scales, and the central hair on the scales changing from a three hairs per follicle to many more. This causes the hair of the Gracilinanus to be thicker and has also found to be heavily pigmented. The last group commonly confused with Marmosops is known as the genus Thylamys. These animals have a contrasting dorsal body pelage and the taxa are actually quite different.
Derby's woolly opossum, or the Central American woolly opossum, is an opossum found in deciduous and moist evergreen forests of Central America, from southern Mexico to western Ecuador and Colombia. It was first described by English naturalist George Robert Waterhouse, and named in honor of Edward Smith-Stanley, 13th Earl of Derby. Derby's woolly opossum is the largest in its genus, with a total length of 60 to 70 centimetres and weight between 200 and 400 grams. The coat is brown and the underside white-buff to golden-brown. The opossum is nocturnal, arboreal (tree-living) and solitary. Diet consists of fruits, nectar, small invertebrates and vertebrates. The time when breeding takes place varies geographically. The litter size ranges from one to six. The IUCN classifies this opossum as least concern.
The Aceramarca gracile opossum or Bolivian gracile opossum is a species of opossum. It is native to Bolivia and Peru, where it occurs in tropical elfin forest habitat.
The heavy-browed mouse opossum, or Anderson's mouse opossum, is a species of opossum in the family Didelphidae. It is endemic to a restricted range in southern Peru. This opossum inhabits forests; it is nocturnal and probably arboreal.
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.
Gracilinanus is a genus of opossum in the family Didelphidae. It was separated from the genus Marmosa in 1989, and has since had the genera Cryptonanus, Chacodelphys, and Hyladelphys removed from it.
The Guahiba gracile opossum is a species of opossum in the family Didelphidae. It is endemic to southern Brazil, where it is known only from three islands, Guahiba, São Lourenço, and Taquara, in the state of Rio Grande do Sul. The poorly studied species is presumed to inhabit subtropical forests, and thus to be threatened by deforestation.
Cryptonanus is a genus of opossums from South America. It includes five species found from Bolivia to Uruguay and eastern Brazil, one of which is now extinct. Although the first species were discovered in 1931, the genus was not recognized as distinct from Gracilinanus until 2005. It includes small opossums with generally grayish, sometimes reddish, fur that are mainly distinguished from other opossums by characters of the skull.
