Abstract
Reports ofCryptosporidiumin various hosts and cross‐transmission experiments are reviewed.Cryptosporidiumhas been found in mammals (Primates, Artiodactyla, Perissodactyla, Carnivora, Lagomorpha, and Rodentia), birds, reptiles, and fish. The only cross‐transmission attempts that have been made have been from mammals to other mammals and to a few birds. Names have been given to 19 “species,” but it is concluded that only four of these should be considered valid at present. These are:C. murisTyzzer, 1907 in mammals,C. meleagridisSlavin, 1955 in birds,C. crotaliTriffit, 1925 in reptiles, andC. nasorumHoover, Hoerr, Carlton, Hinsman & Ferguson, 1981 in fish.