According to Wan, citras were created by bioengineers to discover genetic traits linked to homosexuality. To that end, 90% of them are homosexual males; the rest, both male and female, were used to propagate the species and were known as "citruses." There are no hermaphrodite citras. Their genetic purity prevents such mutations. When the project lost funding, the entire population was ordered to be destroyed. Threatened with extermination, the citras successfully escaped the facility and now live in the wild. Hunting them has since been outlawed.
A citra colony is generally a very primitive and sylvan affair. They live in citrus groves, tending and surviving off of the fruit they raise. A citra's metabolism is incredibly efficient, utilizing very nearly all of the fruit they consume. The drawback is that the citra's body adapts to that fruit only, even changing color, and it must remain with the colony to survive. A citra that consumes anything else or even another citrus fruit can become extremely ill.
Citra colonies sometimes trade their fruit or other services (dancing and adult entertainment being the most popular) for other items they may need or want. From a description of one of the works by Wan: "The citras are useful in providing entertainment to nearby civilized units, and are paid in physical resources." 
Citras and citruses are, overall, similar in appearance to the fennec fox, with long, pointed ears and a bushy tail. They vary in size, but are typically smaller than the standard-sized anthro character. As they grow up, they turn the color of the type of citrus fruit they eat. While a large variety of citras have been portrayed in art, there are five common subspecies, corresponding to the citrus fruit each eats: lime (green), lemon (yellow), grapefruit (light tan), pink grapefruit (pink), and orange (orange). Citras usually range in height from 2' to 3'6" tall. Due to their genetic purity & having been created in a laboratory environment there are few mutations and variant species known to date. Distinctive markings of all citras and citruses include a light patch around their right eye, darker fur on the lower arms, feet, and forepaws, lighter underparts, and two dark rings around the tail.
Citruses retain the tan color of their birth and can usually reach a much greater height than citras.