Biology:Gracilinanus

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Short description: Genus of marsupials


Gracilinanus[1]
Estação Ecológica de Santa Bárbara Giordano Rossi (13).jpg
G. agilis in São Paulo state, Brazil
Scientific classification e
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Marsupialia
Order: Didelphimorphia
Family: Didelphidae
Subfamily: Didelphinae
Tribe: Thylamyini
Genus: Gracilinanus
Gardner & Creighton, 1989
Type species
Didelphys microtarsus
Wagner, 1842
Species

See text

Gracilinanus.png

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.[2] Mouse opossums have ears that are, both, large and naked.[2] General opossums, including Gracilinanus species, have noses that are pointed.[citation needed] Another general characteristic that mouse opossum have are mammary glands.[2] Each member of the Gracilinanus species has a dark ring that is found around each eye.[2][3] The species G. microtarsus has red-brown fur on the top of the body and gray fur on the underside.[4] In comparison with G. microtarsus, G. agilis has paler fur color.[4] 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.[5] 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.[6]

Taxonomy

It contains the following species:[1]

  • 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:[7][8]

G. emilae (Emilia's gracile opossum)

G. aceramarcae (Aceramarca gracile opossum)

G. peruanus

G. microtarsus (Brazilian gracile opossum)

G. agilis (Agile gracile opossum)

Habitat

Gracilinanus species can be found in a number of different places. The different regions that Gracilinanus species can be found are Peru,[9][10] Bolivia,[9][10][11] Brazil,[10][12][13][14] Paraguay,[10] and Venezuela.[12][11][13] Some species are found in forests,[9][10][11][12][13][14] trees,[9][10][12][13][14] fallen trunks, tree holes,[10] humid environments,[13] and coffee plantations.[13] G. emiliae is distributed along the Amazonia and the coast of Venezuelan rainforests.[6] G. emiliae is one of the two species in the genus that is found in lowland Amazonian rainforests.[6] G. agilis and G. microtarsus are the only two species that have been found in the central, south, and southeastern parts of Brazil.[15] The other species have been found in the Amazon and not in Brazil.[15] 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.[5]

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.[10] The only other species that is near threatened is G. dryas.[12] A major threat to these species is that their main habitat is being destroyed by deforestation.[10][11][12][14] 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 other regions in South America but are now extinct there.[3]

Diet

The species G. microtarsus has a diet that includes insects, spiders, fruits, termites, beetles and ants.[16] As well, this species has been known to live off of wasps[17] and small invertebrates.[15] However, the main component of G. microtarsus' diet is ants. It is reported that males eat more food than females.[16]

Reproduction

Like most marsupials, the female has two vaginas and the males have a two-pronged penis.[18] Some females can have a litter size of up to 15, but usually have a litter of about 7.[2] Females of the species do not have a pouch that the young are able to stay in.[3][10][15] 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.[15]

Interesting facts

Some species are nocturnal.[15][17] A few Gracilinanus species know how to play dead.[citation needed] The newest species that was found, G. ignitus, is reported to be one of the largest of all the species.[5] G. emiliae is one of the species that has only a dozen specimens found.[6] The species in this genus are known to climb a lot and dig holes in trees or the ground.[2]

References

  1. 1.0 1.1 Gardner, A.L. (2005). "Order Didelphimorphia". in Wilson, D.E.; Reeder, D.M. Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. pp. 6–7. ISBN 978-0-8018-8221-0. OCLC 62265494. http://www.departments.bucknell.edu/biology/resources/msw3/browse.asp?id=10400050. 
  2. 2.0 2.1 2.2 2.3 2.4 2.5 "Mouse opossum". Encyclopædia Britannica. Encyclopædia Britannica Online Academic Edition. Encyclopædia Britannica Inc., 2012. Web 3 November 2012. <http://www.britannica.com/EBchecked/topic/395096/mouse-opossum>
  3. 3.0 3.1 3.2 "Mammals." EDGE of Existence. Web. 28 November 2012. <http://www.edgeofexistence.org/mammals/species_info.php?id=35 >.
  4. 4.0 4.1 Pires, Mathias M.; Martins, Eduardo G.; Silva, Maria Nazareth F.; dos Reis, Sérgio F. (25 January 2010). "Gracilinanus microtarsus (Didelphimorphia: Didelphidae)". Mammalian Species 42: 33–40. doi:10.1644/851.1. 
  5. 5.0 5.1 5.2 Díaz, M. Mónica; Flores, David A.; Barquez, Rubén M. (2002). "A New Species of Gracile Mouse Opossum, Genus Gracilinanus (Didelphimorphia: Didelphidae), from Argentina". Journal of Mammalogy 83 (3): 824–833. doi:10.1644/1545-1542(2002)083<0824:ANSOGM>2.0.CO;2. 
  6. 6.0 6.1 6.2 6.3 Voss, Robert S.; Fleck, David W.; Jansa, Sharon A. (December 2009). "On the diagnostic characters, ecogeographic distribution, and phylogenetic relationships of Gracilinanus emiliae (Didelphimorphia: Didelphidae: Thylamyini)". Mastozoología neotropical 16 (2): 433–443. https://mn.sarem.org.ar/article/on-the-diagnostic-characters-ecogeographic-distribution-and-phylogenetic-relationships-of-gracilinanus-emiliae/. 
  7. Upham, Nathan S.; Esselstyn, Jacob A.; Jetz, Walter (2019). "Inferring the mammal tree: Species-level sets of phylogenies for questions in ecology, evolution and conservation". PLOS Biol 17 (12): e3000494. doi:10.1371/journal.pbio.3000494. PMID 31800571. 
  8. Amador, Lucila I.; Giannini, Norberto P. (2016). "Phylogeny and evolution of body mass in didelphid marsupials (Marsupialia: Didelphimorphia: Didelphidae)". Organisms Diversity & Evolution 16 (3): 641–657. doi:10.1007/s13127-015-0259-x. 
  9. 9.0 9.1 9.2 9.3 Solari, S.; Tarifa, T. (2016). "Gracilinanus aceramarcae". IUCN Red List of Threatened Species 2016: e.T9416A22169509. doi:10.2305/IUCN.UK.2016-1.RLTS.T9416A22169509.en. https://www.iucnredlist.org/species/9416/22169509. 
  10. 10.0 10.1 10.2 10.3 10.4 10.5 10.6 10.7 10.8 10.9 Carmignotto, A.P.; Solari, S.; de la Sancha, N.; Costa, L. (2015). "Gracilinanus agilis". IUCN Red List of Threatened Species 2015: e.T9417A22169828. doi:10.2305/IUCN.UK.2015-4.RLTS.T9417A22169828.en. https://www.iucnredlist.org/species/9417/22169828. 
  11. 11.0 11.1 11.2 11.3 Pérez-Hernandez, R.; Brito, D.; Astúa, D.; Carmignotto, A.P. (2021). "Gracilinanus emiliae". IUCN Red List of Threatened Species 2021: e.T9419A197307208. doi:10.2305/IUCN.UK.2021-1.RLTS.T9419A197307208.en. https://www.iucnredlist.org/species/9419/197307208. 
  12. 12.0 12.1 12.2 12.3 12.4 12.5 Pérez-Hernandez, R.; Ventura, J.; López Fuster, M. (2016). "Gracilinanus dryas". IUCN Red List of Threatened Species 2016: e.T9418A22169714. doi:10.2305/IUCN.UK.2016-1.RLTS.T9418A22169714.en. https://www.iucnredlist.org/species/9418/22169714. 
  13. 13.0 13.1 13.2 13.3 13.4 13.5 Pérez-Hernandez, R.; Ventura, J.; López Fuster, M. (2016). "Gracilinanus marica". IUCN Red List of Threatened Species 2016: e.T9420A22169944. doi:10.2305/IUCN.UK.2016-1.RLTS.T9420A22169944.en. https://www.iucnredlist.org/species/9420/22169944. 
  14. 14.0 14.1 14.2 14.3 Brito, D.; Astúa, D.; Lew, D.; Soriano, P. (2021). "Gracilinanus microtarsus". IUCN Red List of Threatened Species 2021: e.T9421A197306376. doi:10.2305/IUCN.UK.2021-1.RLTS.T9421A197306376.en. https://www.iucnredlist.org/species/9421/197306376. 
  15. 15.0 15.1 15.2 15.3 15.4 15.5 Geise, Lena; Astúa, Diego (December 2009). "Distribution extension and sympatric occurrence of Gracilinanus agilis and G. microtarsus (Didelphimorphia, Didelphidae), with cytogenetic notes". Biota Neotropica 9 (4): 269–276. doi:10.1590/S1676-06032009000400030. 
  16. 16.0 16.1 Martins, E. G.; Bonato, V.; Pinheiro, H. P.; dos Reis, S. F. (May 2006). "Diet of the gracile mouse opossum (Gracilinanus microtarsus) (Didelphimorphia: Didelphidae) in a Brazilian cerrado: patterns of food consumption and intrapopulation variation". Journal of Zoology 269 (1): 21–28. doi:10.1111/j.1469-7998.2006.00052.x. 
  17. 17.0 17.1 Martins, E. G.; Bonato, V. (1 January 2004). "On the diet of Gracilinanus microtarsus (Marsupialia, Didelphidae) in an Atlantic Rainforest fragment in southeastern Brazil". Mammalian Biology 69 (1): 58–60. doi:10.1078/1616-5047-116. 
  18. Lima, Jussara Marcolino do Nascimento; Santos, Amilton Cesar; Viana, Diego Carvalho; Bertassoli, Bruno Machado; Lobo, Luis Miguel; Oliveira, Vanessa Cristina; Briani, Denis Cristiano; Costa, Gerlane Medeiros et al. (9 December 2013). "Morphological study of the male genital organs of Gracilinanus microtarsus". Brazilian Journal of Veterinary Research and Animal Science 50 (6): 447–456. doi:10.11606/issn.1678-4456.v50i6p447-456. 

Wikidata ☰ Q311603 entry