D. Virginiana (Didelphis Marsupialis)
The text of this paper will cover a description of D. virginiana, its ecology, history, and research involving the species.
The first topic to be discussed by this paper is a description of D. virginiana, which was until recently referred to as Didelphis marsupialis. The description of the opossum will start with a taxonomic description of the species. Following, will be the opossums appearance, and last will be the life cycle of the noted species.
The opossum, Didelphis virginiana, takes its name from two different languages. The name Didelphis is made up of the two Greek words “di”, and “delphys” which stand for “two wombs” referring to the female opossums paired reproductive tract. The name “virginiana”, means “of Virginia” in its Latinized form. This refers to the where the first scientific specimen was found and catalogued (The Georgia). The taxonomic classification of the opossum is as follows: Domain: Eukarya; Kingdom: Animalia; Phylum: Chordata; Class: Mammalia; Order: Marsupialia; Family: Didelphidae; Genus: Didelphis; Species: Virginiana (Savage 45).
The appearance of D. virginiana is quite unique. It has a length of approximately 650 – 900 millimeters (25.4 – 35.1 inches), and a weight of approximately 1.8 – 4.5 kilograms (4 – 10 pounds) (Yahner 11). The opossum has a gray, or black, hair color scheme, with a scaly prehensile tail (Merritt 33). The forefeet and hind feet both have five clawed toes. However, the hind big toe is opposable and resembles a thumb (Merritt 35). The opossum, being a marsupial, also has a pouch (Yahner 11).
The life cycle of Didelphis virginiana is quite interesting, in that it is a marsupial. The opossum becomes sexually mature at one year of age (Merritt 36). Their breeding season stretches from January or February to June or July, producing two litters annually. The females are in heat for approximately thirty days, and the mating session lasts no longer than thirty-six hours (Davis 2). The males forked penis delivers spermatozoa to the, females, paired uteri (Merritt 36). Gestation lasts for an average of twelve days, and produces up to fourteen young (Yahner 12). The young emerge blind, hairless, and pink weighing approximately one tenth of a gram, and measure around thirteen millimeters (Merritt 36).
The just born opossums crawl up into the pouch of their mother, with no assistance, and attach to one of her thirteen nipples (Davis 2). The nipples then enlarge to form a bulb in the mouth of the young. They will remain attached to the nipple for approximately two months (Merritt 37). However, the young will remain in the pouch for seventy to eighty days. After which they will climb out, and onto the mothers back. While on the mothers back the young will begin to eat solid foods. They will remain there until they are one hundred days old, when they...