Rodents comprising the family Caviidae, which includes the guinea pig, rock cavies, mountain cavies, capybara, salt-desert cavy, and mara. All members of the group are indigenous to South America and comprise 15 species in six genera. Cavies have either rounded bodies with large heads and short ears and limbs, or rabbitlike bodies with long limbs and moderately long ears.
The guinea pig (Cavia aperea) originated in Peru, where there is still a wild stock. The domestic form (C. porcellus) has been produced by selective breeding and is a valuable laboratory animal with a life-span of 3–5 years. Closely related to the guinea pig is the mara or Patagonian cavy (Dolichotis patagonum) which resembles a large hare. The salt-desert cavy (Pediolagus salinicola) is a smaller species found in the salt deserts of southern Argentina. The largest of all rodents is the capybara or carpincho (Hydrochoerus hydrochaeris) which grows to the size of a small pig. It is essentially an aquatic animal which lives in small groups along the banks of lakes and streams in tropical South America. See also Rodentia.
