Formed in the early 1900s, the American Rabbit Breeders Association maintains a mission "dedicated to the promotion, development, and improvement of the domestic rabbit and cavy (guinea pig)."
Every five years, the ARBA publishes an updated breed guide with specifications for newly recognized rabbit and cavy breeds and the most popular breeds that are perennial favorites.
It's easy to see that the ARBA has a lot to offer rabbit and cavy enthusiasts.
There are six species of monkey corresponding to those of Guiana and the Amazon valley, the sloth and ant-eater, 12 known genera of rodents, including many species of Mures, the cavy, the capybara, the paca, the nutria, the agouti, the tree porcupine, Loncheres cristata, Echimys cayen and the Brazilian hare.
Among them may be mentioned the aperea or restless cavy (C. porcellus or C. aperea) of Brazil; the Bolivian C. boliviensis, found at great elevations in the Andes; the Brazilian rock-cavy (C. rupestris), characterized by its short blunt claws; and the Peruvian C. cutleri.
A very different animal is the Patagonian cavy, or mara (Dolichotis patachonica), the typical representative of a genus characterized by long limbs, comparatively large ears, and a short tail.