The white-bellied woolly mouse opossum (''Marmosa constantiae'') is a small pouchless

marsupial Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a po ...

of the family Didelphidae. It was formerly assigned to the genus ''

Micoureus 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'' (the "fat-tailed mouse opossums") and '' Tlacuat ...

'', which was made a subgenus of ''

Marmosa 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'' (the "fat-tailed mouse opossums") and '' Tlacua ...

'' in 2009. The specific epithet was given in honour of

Constance Sladen Constance Sladen (11 August 184817 January 1906) was an artist, architectural historian, and philanthropist who was one of the first female members of the Linnean Society of London and founded the Percy Sladen Memorial Trust in memory of her la ...

(née Anderson), wife of the naturalist

Percy Sladen Walter Percy Sladen (30 June 1849 – 11 June 1900) was an English biologist who specialised in starfish. The son of a wealthy leather merchant, Sladen was born near Halifax, Yorkshire on 30 June 1849. He was educated at Hipperholme Grammar Sc ...

. She funded the 1902 expedition which collected the type specimen.

Description

This is one of the larger

mouse opossum 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'' (the "fat-tailed mouse opossums") and '' Tlacuat ...

s, with a head=body length of , a tail in length, and weighing from . The fur is thick and woolly, and is grey over most of the body, fading to buffy-yellow on the head and underparts. There are clear, but narrow, rings of black fur around the eyes. The tail is furred only at the base, and is near black for most of its length, but changes suddenly to pale pink along the last third or so. The feet are broad, with stout claws and ridges on the underside of the toes that aid in climbing trees. Females do not have a pouch, but have fifteen teats arranged in a circle - more than in any of this species' closest relatives.

Distribution and habitat

The opossum is found across northern

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

, in the

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

ian states of

Mato Grosso Mato Grosso ( – lit. "Thick Bush") is one of the states of Brazil, the third largest by area, located in the Central-West region. The state has 1.66% of the Brazilian population and is responsible for 1.9% of the Brazilian GDP. Neighboring ...

and

Mato Grosso do Sul Mato Grosso do Sul () is one of the Midwestern states of Brazil. Neighboring Brazilian states are (from north clockwise) Mato Grosso, Goiás, Minas Gerais, São Paulo and Paraná. It also borders the countries of Paraguay, to the southwest, and ...

, and in northern

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

as far south as

Tucumán Province Tucumán () is the most densely populated, and the second-smallest by land area, of the provinces of Argentina. Located in the northwest of the country, the province has the capital of San Miguel de Tucumán, often shortened to Tucumán. Neigh ...

. It has also recently been reported from

Paraguay Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to th ...

. Across this region, it inhabits moist tropical forests, often near the boundary with drier habitats, and has been found from near sea level to montane forests as high as elevation.

Biology and behaviour

The opossum is

arboreal Arboreal locomotion is the Animal locomotion, locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. Th ...

, solitary, and

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

, spending most of its time in the forest understory. It is omnivorous, feeding on insects (especially bugs) and vegetable matter. Little is known of their reproductive biology, but they appear to breed throughout the year, and mothers have been captured with up to seven young attached to their teats.

References

{{Taxonbar, from=Q194449 Opossums Marsupials of Argentina Mammals of Bolivia Mammals of Brazil Mammals described in 1904 Taxa named by Oldfield Thomas