''Octodon'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

octodontid Octodontidae is a family of rodents, restricted to southwestern South America. Fourteen species of octodontid are recognised, arranged in seven genera. The best known species is the common degu, ''Octodon degus''. Octodontids are medium-sized ...

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are roden ...

s native to

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the souther ...

, in particular in the Chilean

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

. The best-known member is the

common degu The common degu (''Octodon degus''; ), or, historically, the degu, is a small hystricomorpha rodent endemic to the Chilean matorral ecoregion of central Chile. The name ''degu'' on its own indicates either the entire genus '' Octodon'' or, mo ...

, ''O. degus'', which is kept as a pet in various countries. Two of the four species of degus are

nocturnal Nocturnality is an ethology, animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatures generally have ...

.Wise Geek
/ref>University of Michigan

Classification

This genus was first described in 1832 by the British zoologist

Edward Turner Bennett Edward Turner Bennett (6 January 1797 – 21 August 1836) was an English zoologist and writer. He was the elder brother of the botanist John Joseph Bennett.

Taxonomy

The genus name ''Octodon'' comes from the Latin ''octo'', eight, with reference to their teeth, molars and premolars having the shape of the number 8. The full list of species is: * ''O. bridgesii'',

Bridges's degu Bridges's degu (''Octodon bridgesii'') is a species of rodent in the family ''Octodontidae''. It is found in southern Chile. The species was named after Thomas Bridges. Taxonomy Ricardo Ojeda's degu (''O. ricardojedai''), which is found in A ...

, found in central Chile * ''O. degus'', the

or degu, found in central Chile * ''O. lunatus'', the

moon-toothed degu The moon-toothed degu (''Octodon lunatus'') is a species of rodent in the family Octodontidae. It is endemic to Chile, occurring in mountainous areas along the Pacific coast in the central part of the country. Biology and physiology Unlike its c ...

, found in central Chile * ''O. pacificus'', the

Pacific degu The Pacific degu (''Octodon pacificus''), also known as the Mocha Island degu, is a species of rodent in the family Octodontidae. It is endemic to Mocha Island in Chile. Its natural habitat is subtropical or tropical moist lowland forests. It is ...

Mocha Island degu The Pacific degu (''Octodon pacificus''), also known as the Mocha Island degu, is a species of rodent in the family Octodontidae. It is endemic to Mocha Island in Chile. Its natural habitat is subtropical or tropical moist lowland forests. It is ...

, found exclusively on

Mocha Island Mocha Island ( es, link=no, Isla Mocha ) is a small Chilean island located west of the coast of Arauco Province in the Pacific Ocean. The island is approximately in area, with a small chain of mountains running roughly in north-south direction. ...

, Chile *''O. ricardojeda'',

Ricardo Ojeda's degu Ricardo Ojeda's degu (''Octodon ricardojeda'') is a species of rodent in the family Octodontidae. It is found in a small portion of eastern Chile and western Argentina, being the only degu found outside of Chile. It was named after Argentine mam ...

, found in western

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, t ...

and

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the eas ...

Distribution

In the wild, all species of degus live in the

, mainly in the mountains of

, to which most of them are

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found els ...

, aside from a few populations of '' O. ricardojeda'' in the neighboring province of

Neuquén Neuquén (; arn, Nehuenken) is the capital city of the Argentine province of Neuquén and of the Confluencia Department, located in the east of the province. It occupies a strip of land west of the confluence of the Limay and Neuquén rive ...

. They are found between 0 and 1,800 m in

altitude Altitude or height (also sometimes known as depth) is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The exact definition and reference datum varies according to the context ...

Description

They are medium-sized octodontids. Their total body length varies between 200 and 390 mm, with a tail which measures between 81 and 170 mm and represents 70 to 80% of the head + body length. The coat color is grayish, or dull with orange highlights, and turns creamy yellow on the belly. The tail is carried slightly curved and is the same color as the body, and ends with a tuft of black hairs, with the extent of black depending on the species. The ears are quite large and protrude widely from the head, except in ''O. pacificus'' . The lower limbs are suitable for jumping, with pads on the soles of the paws that prevent slipping. The forelegs have four clawed fingers, along with a poorly developed fifth finger with a nail. The

glans The glans (, plural "glandes" ; from the Latin word for "acorn") is a vascular structure located at the tip of the penis in male mammals or a homologous genital structure of the clitoris in female mammals. Structure The exterior structure of ...

of the

penis A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males d ...

is characterized by a variable number of

spikes The SPIKES protocol is a method used in clinical medicine to break bad news to patients and families. As receiving bad news can cause distress and anxiety, clinicians need to deliver the news carefully. By using the SPIKES method for introducing a ...

, 5 or more in number, on each side.

Lifestyle

They are both

and

diurnal Diurnal ("daily") may refer to: General * Diurnal cycle, any pattern that recurs daily ** Diurnality, the behavior of animals and plants that are active in the daytime * Diurnal phase shift, a phase shift of electromagnetic signals * Diurnal tem ...

. Degus are primarily

folivorous In zoology, a folivore is a herbivore that specializes in eating leaves. Mature leaves contain a high proportion of hard-to-digest cellulose, less energy than other types of foods, and often toxic compounds.Jones, S., Martin, R., & Pilbeam, D. ( ...

herbivores. Their diet varies according to annual vegetation cycles. The consumption of their own droppings (

coprophagia Coprophagia () or coprophagy () is the consumption of feces. The word is derived from the grc, κόπρος , "feces" and , "to eat". Coprophagy refers to many kinds of feces-eating, including eating feces of other species (heterospecifics), of ...

) is practiced during times of scarcity. This provides them with a nutritional supplement thanks to the microbial fermentation that takes place in the

cecum The cecum or caecum is a pouch within the peritoneum that is considered to be the beginning of the large intestine. It is typically located on the right side of the body (the same side of the body as the appendix, to which it is joined). The w ...

and optimizes the digestion of fibrous foods. These social animals dig a burrow made of a series of tunnels where they live in small to large groups composed of both males and females.

Conservation status

'' O. bridgesii'' (assessed as conspecific with '' O. ricardojeda'') is considered

vulnerable Vulnerable may refer to: General * Vulnerability * Vulnerability (computing) * Vulnerable adult * Vulnerable species Music Albums * ''Vulnerable'' (Marvin Gaye album), 1997 * ''Vulnerable'' (Tricky album), 2003 * ''Vulnerable'' (The Used album) ...

by the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

, while '' O. pacificus'' is considered critically endangered. The other two species are considered of

least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. Th ...

References

External links

* {{Taxonbar, from=Q628979 Rodent genera Taxa named by Edward Turner Bennett