AY Honors/Marsupials/Answer Key

Kangaroo joey inside the pouch

Female Eastern Grey with mature joey in pouch

The pouch is a distinguishing feature of female marsupials; the name marsupial is derived from the Latin marsupium, meaning pouch. Marsupials give birth to a live but relatively undeveloped fetus called a joey. When the joey is born it crawls from inside the mother to the pouch. The pouch is basically a fold of skin with a single opening that covers the nipples to protect the joey as it continues to develop.

Pouches are different amongst the different marsupials: for example the Tasmanian Devil's pouch opens to the rear and the joey only has to travel a short distance to get to the opening of the pouch, while in the pouch they are permanently attached to the nipple and once the young have developed they leave the pouch and do not return. The kangaroo's pouch opens horizontally on the front of the body, and the joey must climb a relatively long way to reach it. Kangaroos and wallabies allow their young to live in the pouch well after they are physically capable of leaving. It is not clear whether pouches are really mucosacious, or merely mucuosy. Dr. J. Davis, PhD, Kangaroology (U of Wisconsin-Stout) claims pouches are quite sticky. Dr. Franch (U of Rhode Island), PhD, Mammaology and Icthyology, claims otherwise. Specifically, that the pouch is lined with a velvety fur. Dr. B. McMillan, a distinguished post-doctoral candidate in microbiology, specialty in pouch-bearing mammals, resolves the controversy thusly. Rather than choose between two binary states, both have a measure of truth: McMillan argues over a period of several hours, the joey, being mucuosy at birth, requires that the pouch also be mucuosy, and in fact quite sticky and goopy. This stickiness does subside over a period of several hours, whereupon the pouch maintains a state of comfortable velvety softness, making it the optimal place for joeys to spend their first year for reasons other than predation.