Elegant fat-tailed mouse opossum

Last updated

Elegant fat-tailed mouse opossum
Llaca.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Marsupialia
Order: Didelphimorphia
Family: Didelphidae
Genus: Thylamys
Species:
T. elegans
Binomial name
Thylamys elegans
(Waterhouse, 1839)
Thylamys elegans distribution.svg
Range of the elegant fat-tailed mouse opossum
Synonyms [2]

Didelphis elegansWaterhose, 1839
Didelphys soricinaPhilippi, 1894
Marmosa tateiHandley, 1956

Contents

The elegant fat-tailed mouse opossum (Thylamys elegans), 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 (active mainly around twilight) 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.

Taxonomy and etymology

The elegant fat-tailed mouse opossum is the type species of Thylamys , and is placed in the family Didelphidae. It was first described by English naturalist George Robert Waterhouse as Didelphis elegans in 1839. It was given its present binomial name by English zoologist John Edward Gray in 1843. [3] [4]

The cladogram below, based on a 2016 study, shows the phylogenetic relationships of the elegant fat-tailed mouse opossum. [5]

Patagonian opossum (Lestodelphys halli)

Thylamys

Paraguayan fat-tailed mouse opossum (T. macrurus)

Tate's fat-tailed mouse opossum (T. tatei)

Elegant fat-tailed mouse opossum (T. elegans)

White-bellied fat-tailed mouse opossum (T. pallidior)

T. citellus

T. pulchellus

Common fat-tailed mouse opossum (T. pusillus)

The generic name is composed of the Greek words thylas ("pouch") and mys ("mouse"), and the specific name elegans means "elegant" in Latin. Alternate names for this mouse opossum include Chilean mouse opossum, [6] comadreja, llaca, marmosa chilena, marmosa elegante and yaca. [2]

Description

The elegant fat-tailed mouse opossum is a medium-sized opossum characterized by 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. A prominent facial feature is the black ring around either eye; the rings slightly extend toward the nose. The coat color varies geographically. [7] The tail can thicken due to accumulation of fat; the diameter of the tail can reach 1 centimetre (0.39 in) where it is connected to the body. [8] The head-and-body length is 11–13.7 centimetres (4.3–5.4 in); the hindfeet measure 1.7 centimetres (0.67 in), while ears measure 2.3 centimetres (0.91 in). [2]

This opossum can exhibit torpor, a mechanism that allows the opossum to significantly reduce its food and energy requirements. This is similar to hibernation, except that it is only done for a short period of time. [9] Additionally, when water is scarce, the urine tends to become very concentrated. [2]

Ecology and behavior

The elegant fat-tailed mouse opossum is crepuscular (active mainly around twilight). [1] It lives in nests (abandoned by birds and rodents, or built by itself) in tree hollows, under rocks and roots. It is arboreal (tree-living) as well as terrestrial (land-living). The opossum feeds mainly on arthropods and larvae, along with fruits, small vertebrates and carrion. [7] This opossum can use its prehensile tail, regardless of its thickness, to efficiently climb and grasp branches – an ability not as developed in other small Chilean mammals. [10] Nests are generally occupied by one individual; in southern Chile, the home range of this opossum is 1,383 square metres (14,890 sq ft) large in July, and shrinks to 781 square metres (8,410 sq ft) in December. [11] Predators of this opossum include the culpeo fox, burrowing owl and the great horned owl. [2]

Both sexes mature by the first year. A female can have one to two litters in the annual breeding season, typically from September to March. [2] Up to 17 embryos can be produced, [12] but the number of survivors will depend on the number of nipples functioning (typically 11 to 13). [2]

Distribution and status

The elegant fat-tailed mouse opossum occurs in a variety of habitats – from cloud forests to chaparrals, up to an altitude of 2,500 metres (8,200 ft) above the sea level. It occurs to the west of the Andes in central Chile. The IUCN lists this opossum as least concern given its wide distribution and presumably large numbers, but deforestation and agricultural expansion have led to decline in populations in some parts of the range. [1]

Related Research Articles

<span class="mw-page-title-main">Opossum</span> Family of mammals

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.

<span class="mw-page-title-main">White-bellied woolly mouse opossum</span> Species of marsupial

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.

<span class="mw-page-title-main">Linnaeus's mouse opossum</span> Species of marsupial

Linnaeus's mouse opossum, also known as the common or murine mouse opossum, is a South American marsupial of the family Didelphidae.

<span class="mw-page-title-main">Chacoan pygmy opossum</span> Species of marsupial

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.

<span class="mw-page-title-main">Bare-tailed woolly opossum</span> Species of marsupial

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.

<span class="mw-page-title-main">Brown-eared woolly opossum</span> Species of marsupial

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.

<span class="mw-page-title-main">Black-shouldered opossum</span> Species of marsupial

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.

<i>Marmosa</i> Genus of marsupials

The 27 species in the genus Marmosa are relatively small Neotropical members of the family Didelphidae. This genus is one of three that are known as mouse opossums. The others are Thylamys and Tlacuatzin, the grayish mouse opossum. Members of the genus Marmosops used to be called "slender mouse opossums", but are now just called "slender opossums". The thirteen members of the Marmosa subgenus Micoureus, known as woolly mouse opossums, were formerly considered to be a separate genus, but were moved into Marmosa in 2009. Based on a comparison of sequences of one mitochondrial and three nuclear genes, three new subgenera, Eomarmosa, Exulomarmosa and Stegomarmosa, were recognized by Voss et al. in 2014. Eomarmosa and Exulomarmosa, as well as Marmosa and Micoureus, are thought to be sister taxa, while Stegomarmosa is viewed as sister to Marmosa plus Micoureus. Exulomarmosa is a mostly trans-Andean clade.

<span class="mw-page-title-main">Heavy-browed mouse opossum</span> Species of marsupial

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.

<span class="mw-page-title-main">Mexican mouse opossum</span> Species of marsupial

The Mexican mouse opossum is a species of North American opossum in the family Didelphidae.

<i>Thylamys</i> Genus of marsupials

Thylamys is a genus of opossums in the family Didelphidae. The premaxillae are rounded rather than pointed. The females lack a pouch. The females' nipples are arranged in two symmetrical rows on the abdomen. All species but T. macrurus store fat in their tails., although this is not necessarily true for all species in the genus. Fossils belonging to the genus date back to the Miocene, with the oldest specimens being found in the Cerro Azul Formation of Argentina and the Honda Group of Colombia. Genetic studies indicate that the genus may have originated around 14 million years ago.

<span class="mw-page-title-main">Paraguayan fat-tailed mouse opossum</span> Species of marsupial

The Paraguayan fat-tailed mouse opossum is a species of opossum in the family Didelphidae. It is found in forested areas of Brazil and Paraguay. It is known only from a few specimens. For two listed specimens, one had a head-and-body length of about 135 mm and a tail length of about 140 mm, while the other had a head-and-body length of about 120 mm and a tail length of about 155 mm. Most of its fur is gray, but the shoulder areas are reddish gray, and the ventral fur is pure white or creamy white. There is also a ring of black fur surrounding each eye. The ventral surface of the tail is white. The dorsal surface of the tail is gray for the first one third to one half of its length ; the remainder of the dorsal surface of the tail is white. The tail is hairless except for about its first ten mm. Although the genus Thylamys is characterized by fat storage in the tail, there is no evidence that this species stores fat in its tail.

<span class="mw-page-title-main">White-bellied fat-tailed mouse opossum</span> Species of marsupial

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.

<i>Gracilinanus</i> Genus of marsupials

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.

<span class="mw-page-title-main">Cinderella fat-tailed mouse opossum</span> Species of marsupial

The Cinderella fat-tailed mouse opossum is a species of opossum in the family Didelphidae. It is found in northern Argentina and southern Bolivia, in the eastern foothills of the Andes. Its dorsal fur is gray brown to dark brown. Its ventral fur is gray-based, except for the white to yellowish chest hairs. It has been distinguished from T. sponsorius by the well-developed postorbital ridges of the latter, but mitochondrial DNA sequence analysis does not support separate species status for sponsorius.

<span class="mw-page-title-main">Karimi's fat-tailed mouse opossum</span> Species of marsupial

Karimi's fat-tailed mouse opossum is a species of opossum in the family Didelphidae. It is endemic to central and northeast Brazil, where it is found in the cerrado and caatinga at elevations from 300 to 1100 m. This opossum is crepuscular and mostly terrestrial; its omnivorous diet includes leaves, insects and small vertebrates. Its head-and-body length is about 95 millimeters, and its tail length is about 72 millimeters. It is very similar to T. pallidor. Its tail may be nonprehensile. The species is named after Iranian epidemiologist Y. Karimi. It is threatened by habitat destruction and fragmentation due to agriculture and ranching.

<span class="mw-page-title-main">Argentine fat-tailed mouse opossum</span> Species of marsupial

The Argentine fat-tailed mouse opossum was formerly considered a species of opossum in the family Didelphidae. It is found in the eastern foothills of the Andes in northern Argentina and southern Bolivia. Typically reach around 10-13 cm in body length, with a bushy tail adding another 12-15 cm. Its dorsal fur is gray brown to dark brown. Its ventral fur is gray-based except for the white to yellowish chest hairs. It has been distinguished from T. cinderella by its postorbital ridges. T. cinderella has well-developed postorbital ridges in both juveniles and adults that extend laterally behind the eye sockets. Only adults of T. sponsorius have fully developed postorbital ridges, and these do not extend laterally behind the eye sockets. However, mitochondrial DNA sequence analysis does not support the population being distinct from T. cinderella.

<span class="mw-page-title-main">Buff-bellied fat-tailed mouse opossum</span> Species of marsupial

The buff-bellied fat-tailed mouse opossum is a species of opossum in the family Didelphidae. It is found in the transitional and humid forests of northern Argentina and southern Bolivia. Its dorsal fur is cinnamon brown. Most of its ventral fur is gray-based, but its chest, throat, and the thoracic midline are not gray-based. The postorbital ridges are absent in the young and weakly developed in adults.

References

  1. 1 2 3 Solari, S.; Palma, E. (2016). "Thylamys elegans". IUCN Red List of Threatened Species . 2016: e.T40517A22172461. doi: 10.2305/IUCN.UK.2016-1.RLTS.T40517A22172461.en . Retrieved 12 November 2021.
  2. 1 2 3 4 5 6 7 Palma, R.E. (1997). "Thylamys elegans" (PDF). Mammalian Species (572): 1–4. doi:10.2307/3504445. JSTOR   3504445. Archived from the original (PDF) on 2016-03-15. Retrieved 2016-06-01.
  3. Gardner, A.L. (2005). "Order Didelphimorphia". In Wilson, D.E.; Reeder, D.M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 17. ISBN   978-0-8018-8221-0. OCLC   62265494.
  4. Solari, S. (2003). "Diversity and distribution of Thylamys (Didelphidae) in South America, with emphasis on species from the western side of the Andes". In Jones, M.; Dickman, C.; Archer, M. (eds.). Predators with Pouches: The Biology of Carnivorous Marsupials. Collingwood, Australia: CSIRO Publishing. pp. 82–101. ISBN   978-0-643-06634-2.
  5. Amador, L.I.; Giannini, N.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. S2CID   17393886.
  6. Nespolo, R.F.; Bacigalupe, L.D.; Sabat, P.; Bozinovic, F. (2002). "Interplay among energy metabolism, organ mass and digestive enzyme activity in the mouse-opossum Thylamys elegans: the role of thermal acclimation". The Journal of Experimental Biology. 205 (Pt 17): 2697–703. doi:10.1242/jeb.205.17.2697. PMID   12151375.
  7. 1 2 Eisenberg, J.F.; Redford, K.H. (1999). The Central Neotropics: Ecuador, Peru, Bolivia, Brazil. Chicago, US: University of Chicago Press. p. 75. ISBN   978-0-226-19542-1.
  8. Merritt, J.F. (2010). The Biology of Small Mammals. Baltimore, US: Johns Hopkins University Press. pp. 181–2. ISBN   978-0-8018-7950-0.
  9. Lima, M.; Stenseth, N.C.; Yoccoz, N.G.; Jaksic, F.M. (2001). "Demography and population dynamics of the mouse opossum (Thylamys elegans) in semi-arid Chile: seasonality, feedback structure and climate". Proceedings of the Royal Society B: Biological Sciences . 268 (1480): 2053–64. doi:10.1098/rspb.2001.1735. PMC   1088848 . PMID   11571053.
  10. Gallardo-Santis, A.; Simonetti, J.A.; Vásquez, R.A. (2005). "Influence of tree diameter on climbing ability of small mammals". Journal of Mammalogy. 86 (5): 969–73. doi: 10.1644/1545-1542(2005)86[969:IOTDOC]2.0.CO;2 .
  11. Munoz-Pedreros, A.; Murua, R.; Gonzalez, L. (1990). "Nicho ecológico de micromamíferos en un agroecosistema forestal de Chile central" [Ecological niche of small mammals in a central forest agroecosystem, Chile](PDF). Revista Chilena de Historia Natural (in Spanish). 63: 267–77.
  12. Hayssen, V.; Tienhoven, A.; Tienhoven, A. (1993). Asdell's Patterns of Mammalian Reproduction: A Compendium of Species-specific Data (Rev. 2nd ed.). Ithaca, US: Cornell University Press. pp. 12–8. ISBN   978-0-8014-1753-5.