Pouch (marsupial)
Overview
 
The pouch is a distinguishing feature of female marsupial
Marsupial
Marsupials are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central...

s (and rarely in the males as in the water opossum
Water Opossum
The water opossum , also locally known as the yapok, is a marsupial of the family Didelphidae. It is the only member of its genus, Chironectes...

 and the extinct Thylacine
Thylacine
The thylacine or ,also ;binomial name: Thylacinus cynocephalus, Greek for "dog-headed pouched one") was the largest known carnivorous marsupial of modern times. It is commonly known as the Tasmanian tiger or the Tasmanian wolf...

); the name marsupial is derived from the Latin marsupium
Marsupium
Marsupium is the Latin word for a pouch in several animal groups:* Pouch , in marsupials* Brood pouch , in peracarid crustaceans* Brood pouch , in syngnathids such as sea horses...

, meaning "pouch
Pouch
Pouch may refer to:* A small bag such as a pocket, teabag, money pouch, sporran, etc* Cadaver pouch, body bag * Diplomatic pouch* Electric heating pouch, medical apparatus, electric heating device for curative treatment...

". Marsupials give birth to a live but relatively undeveloped fetus
Fetus
A fetus is a developing mammal or other viviparous vertebrate after the embryonic stage and before birth.In humans, the fetal stage of prenatal development starts at the beginning of the 11th week in gestational age, which is the 9th week after fertilization.-Etymology and spelling variations:The...

 called a joey. When the joey is born it crawls from inside the mother to the pouch. The pouch is a fold of skin with a single opening that covers the nipple
Nipple
In its most general form, a nipple is a structure from which a fluid emanates. More specifically, it is the projection on the breasts or udder of a mammal by which breast milk is delivered to a mother's young. In this sense, it is often called a teat, especially when referring to non-humans, and...

s to protect the joey as it continues to develop.

Pouches are different amongst the different marsupials: for example for Quoll
Quoll
The quoll, or native cat, is a carnivorous marsupial native to mainland Australia, New Guinea and Tasmania. It is primarily nocturnal and spends most of the day in its den. There are six species of quoll; four are found in Australia and two in New Guinea...

s and Tasmanian Devil
Tasmanian Devil
The Tasmanian devil is a carnivorous marsupial of the family Dasyuridae, now found in the wild only on the Australian island state of Tasmania. The size of a small dog, it became the largest carnivorous marsupial in the world following the extinction of the thylacine in 1936...

s, the pouch opens to the rear and the joey only has to travel a short distance to get to the opening (resting place) of the pouch.
Encyclopedia
The pouch is a distinguishing feature of female marsupial
Marsupial
Marsupials are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central...

s (and rarely in the males as in the water opossum
Water Opossum
The water opossum , also locally known as the yapok, is a marsupial of the family Didelphidae. It is the only member of its genus, Chironectes...

 and the extinct Thylacine
Thylacine
The thylacine or ,also ;binomial name: Thylacinus cynocephalus, Greek for "dog-headed pouched one") was the largest known carnivorous marsupial of modern times. It is commonly known as the Tasmanian tiger or the Tasmanian wolf...

); the name marsupial is derived from the Latin marsupium
Marsupium
Marsupium is the Latin word for a pouch in several animal groups:* Pouch , in marsupials* Brood pouch , in peracarid crustaceans* Brood pouch , in syngnathids such as sea horses...

, meaning "pouch
Pouch
Pouch may refer to:* A small bag such as a pocket, teabag, money pouch, sporran, etc* Cadaver pouch, body bag * Diplomatic pouch* Electric heating pouch, medical apparatus, electric heating device for curative treatment...

". Marsupials give birth to a live but relatively undeveloped fetus
Fetus
A fetus is a developing mammal or other viviparous vertebrate after the embryonic stage and before birth.In humans, the fetal stage of prenatal development starts at the beginning of the 11th week in gestational age, which is the 9th week after fertilization.-Etymology and spelling variations:The...

 called a joey. When the joey is born it crawls from inside the mother to the pouch. The pouch is a fold of skin with a single opening that covers the nipple
Nipple
In its most general form, a nipple is a structure from which a fluid emanates. More specifically, it is the projection on the breasts or udder of a mammal by which breast milk is delivered to a mother's young. In this sense, it is often called a teat, especially when referring to non-humans, and...

s to protect the joey as it continues to develop.

Pouches are different amongst the different marsupials: for example for Quoll
Quoll
The quoll, or native cat, is a carnivorous marsupial native to mainland Australia, New Guinea and Tasmania. It is primarily nocturnal and spends most of the day in its den. There are six species of quoll; four are found in Australia and two in New Guinea...

s and Tasmanian Devil
Tasmanian Devil
The Tasmanian devil is a carnivorous marsupial of the family Dasyuridae, now found in the wild only on the Australian island state of Tasmania. The size of a small dog, it became the largest carnivorous marsupial in the world following the extinction of the thylacine in 1936...

s, the pouch opens to the rear and the joey only has to travel a short distance to get to the opening (resting place) 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
Kangaroo
A kangaroo is a marsupial from the family Macropodidae . In common use the term is used to describe the largest species from this family, especially those of the genus Macropus, Red Kangaroo, Antilopine Kangaroo, Eastern Grey Kangaroo and Western Grey Kangaroo. Kangaroos are endemic to the country...

'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
Wallaby
A wallaby is any of about thirty species of macropod . It is an informal designation generally used for any macropod that is smaller than a kangaroo or wallaroo that has not been given some other name.-Overview:...

 allow their young to live in the pouch well after they are physically capable of leaving, often keeping two different joeys in the pouch, one tiny and one fully developed.

See also

  • For more about the nature and usage of the pouch, see Marsupials#Description
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