The big lutrine opossum (''Lutreolina crassicaudata''), also called little water opossum, thick-tailed opossum and coligrueso, is a long-tailed, otter-like

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

native to grasslands of

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

. It generally lives near water and is active at night, dawn or dusk. It eats mice, insects and crabs. Like all

opossum 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 A ...

s, it is a

marsupial Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a r ...

and carries its young in a pouch.

Description

The big lutrine opossum ("lutrine" means "otter-like" and "crass" meaning "thick, fat" and "cauda" meaning "tail") is a very peculiar opossum, having a long

weasel Weasels are mammals of the genus ''Mustela'' of the family Mustelidae. The genus ''Mustela'' includes the least weasels, polecats, stoats, ferrets, and European mink. Members of this genus are small, active predators, with long and slend ...

-like body, short legs, small rounded ears, and dense reddish or yellowish fur. Nocturnal and

crepuscular In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal (active during dawn), vespertine (biology), vespertine/vespertinal (active during dusk), or both. This is distinguished from diurnalit ...

, they generally live in grasslands and savannas near water. They are terrestrial but are excellent swimmers and climbers.

Distribution and habitat

The big lutrine opossum is distributed in

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

Bolivia Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...

Uruguay Uruguay, officially the Oriental Republic of Uruguay, is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast, while bordering the Río de la Plata to the south and the A ...

Paraguay Paraguay, officially the Republic of Paraguay, is a landlocked country in South America. It is bordered by Argentina to the Argentina–Paraguay border, south and southwest, Brazil to the Brazil–Paraguay border, east and northeast, and Boli ...

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

and

Guyana Guyana, officially the Co-operative Republic of Guyana, is a country on the northern coast of South America, part of the historic British West Indies. entry "Guyana" Georgetown, Guyana, Georgetown is the capital of Guyana and is also the co ...

. Populations in the two last countries are isolated from the populations of all the other countries. It can be found in grasslands, savanna grassland, and gallery woodlands with permanent water bodies, in marshy or

riparian A riparian zone or riparian area is the interface between land and a river or stream. In some regions, the terms riparian woodland, riparian forest, riparian buffer zone, riparian corridor, and riparian strip are used to characterize a ripar ...

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

Behavior and ecology

The big lutrine opossum builds tight nests made of grass and reeds or utilize abandoned armadillo or viscacha burrows.

Diet

With a skull adapted for carnivory, the big lutrine opossum is carnivorous and insectivorous feeding on small rodents and lagomorphs, birds, insects, small crustaceans. It is considered to be the most carnivorous of all the members of the order Didelphimorphia. It preys on venomous snakes. Captive individuals have been observed eating butterfish mixed with meat, frogs, earthworms, shrimp and mice. Big lutrine opossums living close to urban areas scavenge through garbage, but this behavior is isolated and likely occurs due to necessity because there is less available prey in urban areas.

Reproduction

Breeding begins in September and carries on until April followed by approximately five months of anestrous, or time without estrus. Big lutrine opossums have two breeding periods per year resulting in litters of 7–11 offspring. Like most marsupials, litters are born into a pouch and are fed via lactation until the offspring is developed enough to leave the pouch. Gestation lasts approximately two weeks and young are weaned off mother's milk at around three months. The first litter is born in September and the second in December or January. The offspring from this breeding season reach sexual maturity at six months but do not begin reproducing until the following year. Males are heavier than females indicating sexual dimorphism likely caused by male-male competition for mates.

Locomotion

The big lutrine opossum is quadrupedal and extremely agile. It is primarily terrestrial but also an adept climber and swimmer. Its long body, proportionally short limbs, and no undulation of the vertebral column disqualifies it from being categorized as a specialized semi-aquatic mammal. Although it cannot be classified as a truly specialized mammal, it is a strong swimmer drawing power from the hind limbs as the forelimbs paddle. By employing a variety of gaits its locomotion abilities allows it to run, walk, climb, swim through all the different kinds of obstacles found in the grassy-woodland and marshy areas in which it lives. It can dive and swim with ease, expanding its prey base to aquatic invertebrates.

Taxonomy

*'' Lutreolina crassicaudata crassicaudata'' *'' Lutreolina crassicaudata paranalis'' *'' Lutreolina crassicaudata turneri''

Evolution

Fossils found in Minas Gerais, Brazil indicate that the big lutrine opossum emerged in the late

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

epoch. Lutreolina fossils found in Tarija, Bolivia as well as samples uncovered across Argentina also indicate appearance of lutrine opossum ancestors during the late Pleistocene. For a short time in Argentina, the opossums were hunted for their pelts for fur trade and to line garments, but this market quickly declined because the color of the opossum pelts would fade over time. Genetic and morphological studies indicate that the population in the Yungas, which was formerly considered a population of ''L. crassicaudata'' (with both species being grouped under the common name "lutrine opossum"), is in fact a distinct species, Massoia's lutrine opossum (''Lutreolina massoia''). As its name suggests, the big lutrine opossum is larger than Massoia's lutrine opossum. Juan A. Martínez-Lanfranco , David Flores , J. Pablo Jayat , and Guillermo D'Elía, A new species of lutrine opossum, genus Lutreolina Thomas (Didelphidae), from the South American Yungas, Source: Journal of Mammalogy, 95(2):225-240. 2014.

References

{{Taxonbar, from=Q1210170 Opossums Marsupials of Argentina Marsupials of Brazil Marsupials of Bolivia Mammals of Paraguay Mammals of Uruguay Marsupials of Colombia Mammals of Guyana Marsupials of Venezuela Mammals described in 1804 Taxa named by Anselme Gaëtan Desmarest