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The lutrine opossum (Lutreolina crassicaudata), also known as the little water opossum, thick-tailed opossum, or coligrueso is an opossum species from South America and is monotypic in the genus Lutreolina.[2]

Lutrine opossum
Lutreolina crassicaudata - Museo Civico di Storia Naturale Giacomo Doria - Genoa, Italy - DSC02971.JPG
Scientific classification edit
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Marsupialia
Order: Didelphimorphia
Family: Didelphidae
Subfamily: Didelphinae
Genus: Lutreolina
Thomas, 1910
L. crassicaudata
Binomial name
Lutreolina crassicaudata
Desmarest, 1804

L. crassicaudata crassicaudata
L. crassicaudata paranalis
L. crassicaudata turneri

Little Water Opossum area.png
Lutrine opossum range



The lutrine opossum ("lutrine" means "otter-like" and "crass" meaning "thick, fat" and "cauda" meaning "tail") is a very peculiar opossum, having a long weasel-like body, short legs, small rounded ears, and dense reddish or yellowish fur.[3] Nocturnal and crepuscular, they generally live in grasslands and savannas near water. They are terrestrial but are excellent swimmers and climbers.[4]

Genetic and morphological studies indicate that there is a second species, Lutreolina massoia.[5]


Range and habitatEdit

Lutreolina crassicaudata is found in Brazil, Argentina, Bolivia, Uruguay, Paraguay, Colombia and Guyana. 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 habitats. They build tight nests made of grass and reeds or utilize abandoned armadillo or viscacha burrows [6]


With a skull adapted for carnivory,[6] Lutrine opossums are carnivorous and insectivorous feeding on small rodents and lagomorphs, birds, insects, small crustaceans.[7] They are considered to be the most carnivorous of all the members of the order Didelphimorphia.[4] Captive populations have been observed eating butterfish mixed with meat, frogs, earthworms, shrimp at mice.[7] Populations located close to urban areas have been known to scavenge through garbage but this behavior is isolated to these populations and likely occurs due necessity because there is less available prey in urban areas.[4]

Lutreolina crassicaudata skull. [citation 2]

Life historyEdit

Fossils found in Minas Gerais, Brazil indicate that L. crassicaudata emerged in the late Pleistocene 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.[3] 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.[3]



Breeding begins in September and carries on until April follow by approximately fives months of anestrous, or time without estrus. Lutrine opossums have two breeding periods per year resulting in litters of 7-11 offspring. Like all 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 3 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 6 months but don't begin reproducing until the following year.[4] Males are heavier than females indicating sexual dimorphism likely caused by male-male competition for mates.


Lutrine opossums are quadrupedal and extremely agile. Although they are primarily terrestrial they are also adept climbers and swimmers.[3] Their long body, proportionally short limbs, and no undulation of the vertebral column disqualifies them from being categorized as a specialized semi-aquatic mammal. Although they cannot be classified as truly specialized mammals, they are still considered strong swimmers drawing power from the hind limbs as the forelimbs paddle.[6] By employing a variety of gaits their locomotion abilities allows them to run, walk, climb, swim through all the different kinds of obstacles found in the grassy-woodland and marshy areas in which they live.[6] They can dive and swim with ease, expanding their prey base to aquatic invertebrates.[3]



  1. ^ Lew, D.; Pérez-Hernandez, R.; de la Sancha, N.; Flores, D. & Teta, P. (2011). "Lutreolina crassicaudata". IUCN Red List of Threatened Species. Version 2011.2. International Union for Conservation of Nature. Retrieved 18 January 2012.
  2. ^ 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. 8. ISBN 978-0-8018-8221-0. OCLC 62265494.
  3. ^ a b c d e Marshall, Larry G. (6 January 1978). "Lutreolina crassicaudata". The American Society of Mammalogists: Mammalian Species.
  4. ^ a b c d Regidor, Héctor A.; Gorostiague, Martín; Sühring, Silvia. "Reproduction and dental age classes of the little water opossum (Lutreolina crassicaudata) in Buenos Aires, Argentina". Revista de Biología Tropical. 47 (1–2): 271–272. ISSN 0034-7744.
  5. ^ 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.
  6. ^ a b c d Santori, Ricardo Tadeu; Rocha-Barbosa, Oscar; Vieira, Marcus Vinícius; Magnan-Neto, José Aarão; Loguercio, Mariana F. C. (2005-10-01). "Locomotion in Aquatic, Terrestrial, and Arboreal Habitat of Thick-Tailed Opossum, Lutreolina crassicaudata (Desmarest, 1804)". Journal of Mammalogy. 86 (5): 902–908. doi:10.1644/1545-1542(2005)86[902:liataa];2. JSTOR 4094435.
  7. ^ a b Facure, Kátia Gomes; do Nascimento Ramos, Vanessa (2011-03-01). "Food habits of the thick-tailed opossum Lutreolina crassicaudata (Didelphimorphia, Didelphidae) in two urban areas of southeastern Brazil". Mammalian Biology - Zeitschrift für Säugetierkunde. 76 (2): 234–236. doi:10.1016/j.mambio.2010.06.005.
  • John F. Eisenberg and Kent H. Redford, 2000. Mammals of Neotropics: Ecuador, Bolivia and Brazil.