Gracilinanus

''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.

Physical description

Gracile mouse opossums, excluding the fat-tailed mouse opossum, in general, have a prehensile tail that is thin and very long. The tails of mouse opossums are naked."Mouse opossum". Encyclopædia Britannica. Encyclopædia Britannica Online Academic Edition. Encyclopædia Britannica Inc., 2012. Web 3 November 2012. Mouse opossums have ears that are, both, large and naked. General opossums, including ''Gracilinanus'' species, have noses that are pointed. Another general characteristic that mouse opossum have are mammary glands. Each member of the ''Gracilinanus'' species has a dark ring that is found around each eye."Mammals." EDGE of Existence. Web. 28 November 2012. . The species ''G. microtarsus'' has red-brown fur on the top of the body and gray fur on the underside. In comparison with ''G. microtarsus'', ''G. agilis'' has paler fur color. Over the years, a new species, ''G. ignitus'', has been added to the genus. ''G. ignitus'' has a white patch on its chest. It, as well, has a light, two-tone colored tail that has only a few hairs. The fur color can be used to determine if a member of the genus is part of the ''G. ignitus'' species. ''G. microtarsus'', ''G. emiliae'', and ''G. dryas'' can be distinguished from ''G. ignitus'' by their tails that are only one color. One difference between ''G. agilis'' and ''G. ignitus'' is that ''G. agilis'' has a hairier tail. ''G. aceramarcae'' has naked skin compared to ''G. ignitus''. ''G. emiliae'' is smaller than ''G. ignitus''. ''G. emiliae'', in general, has a very long tail. A difference between ''G. emiliae'' and the rest of the species in the genus is that it has white fur on the underside of the body and the rest of the species have a gray or brown color.

Taxonomy

It contains the following species:
* Aceramarca gracile opossum (''Gracilinanus aceramarcae'')
* Agile gracile opossum (''Gracilinanus agilis'')
* Wood sprite gracile opossum (''Gracilinanus dryas'')
* Emilia's gracile opossum (''Gracilinanus emilae'')
* Northern gracile opossum (''Gracilinanus marica'')
* Brazilian gracile opossum (''Gracilinanus microtarsus'')

Cladogram of living ''Gracilinanus'' species:

Habitat

''Gracilinanus'' species can be found in a number of different places. The different regions that ''Gracilinanus'' species can be found are Peru, Bolivia, Brazil, Paraguay, and Venezuela. Some species are found in forests, trees, fallen trunks, tree holes, humid environments, and coffee plantations. ''G. emiliae'' is distributed along the Amazonia and the coast of Venezuelan rainforests. ''G. emiliae'' is one of the two species in the genus that is found in lowland Amazonian rainforests. ''G. agilis'' and ''G. microtarsus'' are the only two species that have been found in the central, south, and southeastern parts of Brazil. The other species have been found in the Amazon and not in Brazil. The production of sugar cane and fruits, along with deforestation, is thought to be a reason why the newer species, ''G. ignitus'', has been harder to find.

Endangerment

Out of the species that currently exist, only two are on the endangered list. ''Gracilinanus agilis'' is not considered to be threatened, in general, but in the specific area of Paraguay, the species is close to being threatened. The only other species that is near threatened is ''G. dryas''. A major threat to these species is that their main habitat is being destroyed by deforestation. However, it has also been reported that these species are on the critically endangered list because they are only known in two general areas where their habitat has been found to be taking a decline. The species of the genus ''Gracilinanus'' once occupied regions in South America and Europe, but are now extinct there.

Diet

The species ''G. microtarsus'' has a diet that includes insects, spiders, fruits, termites, beetles and ants. As well, this species has been known to live off of wasps and small invertebrates. However, the main component of ''G. microtarsus''’ diet is ants. It is reported that the male species eat more food than the females.

Reproduction

Like most marsupials, the female has two vaginas and the males have a two-pronged penis. Some females can have a litter size of up to 15, but usually have a litter of about 7. Females of the species do not have a pouch that the young are able to stay in. For those that do not have a pouch, the young are only attached to the nipples for a short time period and are left in their nests early on in their life.

Interesting facts

Some species are nocturnal. A few ''Gracilinanus'' species know how to play dead. The newest species that was found, ''G. ignitus'', is reported to be one of the largest of all the species. ''G. emiliae'' is one of the species that has only a dozen specimens found. The species in this genus are known to climb a lot and dig holes in trees or the ground.

References

{{Taxonbar, from=Q311603

Opossums
Marsupial genera
Taxa named by Johann Andreas Wagner
Taxonomy articles created by Polbot