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Opossums are marsupials , that is, mammals whose females have a pouch or folds surrounding the teats to which the developing embryos attach once outside the uterus. They are related to kangaroos, koalas, and wombats, among others.
Opossums are distributed from Canada to Argentina, and are named depending on the region and country. Some of its common names are: opossum (Canada and USA); chucha, runcho, fara, shrimp, jujube (Colombia); weasel (Argentina, Paraguay); carachupa (Bolivia); mucura, fox, muca, shrimp (Brazil, Peru); fox, yalu, big fox (Ecuador); fox, hairless fox (Panama); intuto (Peru); Rabipelado (Venezuela); tacuzin (Central America); tlacauche (Mexico). For the most part, these animals have nocturnal habits and preferably occupy the trees.
Distinctive physical characteristics
Face. Opossums have long, cone-shaped rostrums. Some species have light spots over the eyes. They have a well-developed bone structure called the post-orbital bar that surrounds the back of the eye socket. Also, their skull has a bony protrusion running down the middle of it called the sagittal crest.
Prehensile tail . Opossums have a tail covered with diamond-shaped scales, arranged in a spiral. This structure presents variations according to the species: it can be prehensile or not; its length may be less than, equal to or greater than the head-body length; the base may be little or very hairy. If the tail is prehensile, they use it to hold objects and hang from branches.
Opposable thumb. Like humans and other primates, opossums have five fingers, one of which is a thumb that allows them to hold on. This finger is scaly, without nails and without hairs.
Fur. These marsupials exhibit fur coloration that varies with the species. Some have black, gray or chestnut backs. The heads of certain species have black lines running from the nose to the ears.
Reproduction
Opossums are distinguished by their short gestation periods ranging from 8 to 45 days, depending on the species. After this, the young are born in a state of incomplete development and migrate from the uterus to a bag called the marsupium, inside which are the mammary glands to which they adhere until their development is complete. Newly hatched pups weigh less than one (1) gram.
The females have between 10 to 13 nipples. However, the number of pups is usually greater than the number of nipples, which is why many of them do not reach adulthood, taking into account that to survive they must be attached to one of the nipples inside the pouch for one to two months. When leaving the pouch, the pups are independent.
Ecology
Opossums are omnivorous. Since a large part of their diet is made up of fruits, they contribute to the dispersal of seeds of pioneer plants, an important function in the process of restoring disturbed areas. The dispersal is carried out by means of the transport of seeds in the digestive tract of the opossums (a phenomenon called endozoochory) and their excretion through feces or regurgitum in conditions and places that are appropriate for the development of the plant embryo. Seed transit through the digestive system helps to scarify those whose outer wall is very strong, which contributes to successful germination.
taxonomy
The diversity of marsupials is so wide that no definitive consensus on taxonomic classification has been reached. However, it is accepted that the taxonomy of opossums is as follows.
- Animalia Kingdom.
- Phylum : Chordata .
- Class: Mamalia.
- Order: Marsupialia.
- Family: Didelphidae .
- Suborder: Didelphimorphia .
- Subfamily: Didelphinae .
- Subclass: Methateria .
- Genus: Didelphis .
- Species: Marsupialis .
- Scientific names of some species: Didelphis virginiana , Didelphis albiventris , Didelphis marsupialis .
Sources
Flórez-Oliveros FJ, Vivas-Serna C. Opossums (common chuchas), marmosas and shorttails in Colombia . Zarigüeya Foundation – FUNDZAR, Medellin, Colombia. 264pp, 2020.
Moreno, V. Didelphis marsupialis, Linnaeus 1758 (opossum): a contribution to its knowledge, use and conservation . University of Cundinamarca., nd
Rueda, M., Ramírez, G., Osorio, J. Approach to the biology of the common opossum (didelphismarsupialis) . Scientific Bulletin Center of Museums – Museum of Natural History . 17(2): 141-153, 2013.
