The Biology and Identification of the Coccidia (Apicomplexa) of Marsupials of the World contains the most up-to-date information on the former order marsupial that is now partitioned by mammalogists into seven separate orders that contain 20 families, 86 genera, and 318 species that live on land or in trees in Oceania and the Americas. Marsupials, like other vertebrate animals have many different kinds of parasites (e.g. viruses, protozoa, worms, arthropods, etc.), but there is no definitive text that covers any one of these groups found in all marsupials. Coccidiosis is a serious global problem in most domesticated animals, and under increasing circumstances of loss of habitat and crowding, may also affect some wild animal populations, thus, there is a real need for their identification and control.