The guinea pig or domestic guinea pig, also known as the cavy or domestic cavy, is a species of rodent belonging to the genus Cavia, family Caviidae. Breeders tend to use the name "cavy" for the animal, but "guinea pig" is more commonly used in scientific and laboratory contexts. Despite their name, guinea pigs are not native to Guinea, nor are they closely related to pigs. Instead, they originated in the Andes region of South America, where wild guinea pigs can still be found today. Studies based on biochemistry and DNA hybridization suggest they are domesticated animals that do not exist naturally in the wild, but are descendants of a closely related cavy species such as C. tschudii. Originally, they were domesticated as livestock at the Andean region and are still consumed in some parts of the world.
Caviidae, the cavy family, is composed of rodents native to South America and includes the domestic guinea pig, wild cavies, and the largest living rodent, the capybara. They are found across South America in open areas from moist savanna to thorn forests or scrub desert. This family of rodents has fewer members than most other rodent families, with 19 species in 6 genera in 3 subfamilies.
Maras, subfamily Dolichotinae, are a group of rodents in the family Caviidae. These large relatives of guinea pigs are common in the Patagonian steppes of Argentina, but also live in Paraguay and elsewhere in South America. There are two extant species, the Patagonian mara of the genus Dolichotis and the Chacoan mara of the genus Pediolagus. Traditionally this species was also thought to belong to Dolichotis; however, a 2020 study by the American Society of Mammalogists found significant difference between the two mara species to warrant resurrecting the genus Pediolagus for it. Several extinct genera are also known.
The genus Hydrochoerus contains two living and three extinct species of rodents from South America, the Caribbean island of Grenada, California and Panama. Capybaras are the largest living rodents in the world. The genus name is derived from the Greek ὕδωρ 'water' plus χοίρος 'pig'.
Dolichotis is a genus of the cavy family of rodents. These large relatives of guinea pigs are common in the Patagonian steppes of Argentina, but also live in Paraguay and elsewhere in South America. It contains a single extant species, the Patagonian mara, which is one of the largest rodents in the world after the two species each of capybaras and beavers, and the large species of porcupines, reaching about 45 cm (18 in) in height.
Caviomorpha is the rodent parvorder that unites all New World hystricognaths. It is supported by both fossil and molecular evidence. The Caviomorpha was for a time considered to be a separate order outside the Rodentia, but is now accepted as a genuine part of the rodents. Caviomorphs include the extinct Heptaxodontidae, the extinct Josephoartigasia monesi and extant families of chinchilla rats, hutias, guinea pigs and the capybara, chinchillas and viscachas, tuco-tucos, agoutis, pacas, pacaranas, spiny rats, New World porcupines, coypu and octodonts.
Hystricomorpha is a term referring to families and orders of rodents which has had many definitions throughout its history. In the broadest sense, it refers to any rodent with a hystricomorphous zygomasseteric system. This includes the Hystricognathi, Ctenodactylidae, Anomaluridae, and Pedetidae. Molecular and morphological results suggest the inclusion of the Anomaluridae and Pedetidae in Hystricomorpha may be suspect. Based on Carleton & Musser 2005, these two families are discussed here as representing a distinct suborder Anomaluromorpha.
Caviinae is a subfamily uniting all living members of the family Caviidae with the exception of the maras, capybaras, and Kerodon. The subfamily traditionally contained the guinea pig or cavy-like forms along with the cursorially adapted (running) Kerodon. Molecular results suggest the Caviinae as so defined would be paraphyletic and Kerodon is more closely related to maras and capybaras than to other caviines. This led Woods and Kilpatrick (2005) to unite Kerodon and capybaras into the subfamily Hydrochoerinae within the Caviidae. These studies also suggest Microcavia and Cavia are more closely related to one another than either is to Galea.
The genus Kerodon contains two species of South American rock cavies, related to capybaras and guinea pigs. They are found in semiarid regions of northeast Brazil known as the Caatinga. This area has a rocky terrain with large granite boulders that contain rifts and hollows where Kerodon species primarily live.
The Chacoan mara or Chacoan cavy is a relatively large South American rodent of the cavy family. They are a close relative of the better known Patagonian mara. The Chacoan mara is the sole member of the genus Pediolagus.
Hydrochoerinae is a subfamily of Caviidae, consisting of two living genera, Hydrochoerus, the capybaras, and Kerodon, the rock cavies. In addition, a number of extinct genera related to capybaras should also be placed in this subfamily. The taxonomy of Hydrochoerinae is confused because, until 2005, living capybaras and their extinct relatives were placed in their own family, Hydrochoeridae. Recent molecular phylogenetic studies recognize a close relationship between Hydrochoerus and Kerodon, supporting placement of both genera in a subfamily of Caviidae. Paleontological classifications have yet to incorporate this new taxonomy, and continue to use Hydrochoeridae for all capybaras, while using Hydrochoerinae for the living genus and its closest fossil relatives such as Neochoerus. The taxonomy of fossil hydrochoerines is also in a state of flux. In recent years, the diversity of fossil hydrochoerines has been substantially reduced. This is largely due to the recognition that capybara molar teeth show strong variation in shape over the life of an individual. In one instance, material once referred to four genera and seven species on the basis of differences in molar shape is now thought to represent differently aged individuals of a single species, Cardiatherium paranense.
The Brazilian guinea pig is a guinea pig species found in Argentina, Brazil, Bolivia, Colombia, Ecuador, Guyana, Paraguay, Uruguay and Venezuela.
Santa Catarina's guinea pig or Moleques do Sul cavy is a rare guinea pig species of southeastern South America.
The montane guinea pig is a species of caviid rodent found in the Andes in South America. The montane guinea pig is the likely main ancestor of Cavia porcellus, the domestic guinea pig or domestic cavy, which appears to be a hybrid that includes lesser genetic contributions from other Cavia species.
Cavia anolaimae is a guinea pig species from South America. It is found in Colombia near Bogotá. It is believed to be a feral offshoot of the domestic guinea pig, Cavia porcellus, and is often treated as a synonym of C. porcellus, but Zúñiga et al. (2002), based on morphologic characters, recognized them as different species. According to the molecular analysis of Dunnum and Salazar (2010) C. anolaimae is a subspecies of Cavia aperea, C. aperea anolaimae, and a possible synonymous of C. a. guianae.
Cavia guianae is a guinea pig species from South America. It is found in southern Venezuela, Guyana, and portions of northern Brazil. Some biologists believe it to be a feral offshoot of the domestic guinea pig, Cavia porcellus; others subsume it under the wild cavy, Cavia aperea. Molecular data collected show there is little genetic differentiation in C.a. guianae known to be a lowland locality in comparison to C. anolaimae which are predominantly highland populations.
The common yellow-toothed cavy is a species of rodent in the family Caviidae, closely related to the domesticated guinea pig. It is found in Argentina, Bolivia, Chile, and Peru. Its karyotype has 2n = 68 and FN = 136. G. musteloides is the most common and widely found member of Galea, and is present at elevations ranging from 20 to 5000 m above sea level. It has yellow teeth.
Thrichomys is a genus of South American rodents in the family Echimyidae. It contains at least five species, found in Bolivia, Brazil and Paraguay. They are as follows:
Galea is a genus of South American rodents of the family Caviidae. 5-6 extant species are known, found in Argentina, Bolivia, Chile, Peru and Brazil. They are:
Dr. Barbara J. Weir was a scientist, adventurer, and editor from the United Kingdom. Her discovery and extensive study of estrus in Galea musteloides illuminated the workings of some rodents' reproductive systems. Barbara Weir is most recognized for her comparative study on the breeding habits of Cavia aperea, and two related species, Galea musteloides, and Microcavia australis. Weir was also an editor for the Journal of Reproduction and Fertility from 1976 to 1990 where she was recognized for her "firm and fair role" as editor.
