A New Eimeria Species (Apicomplexa: Eimeriidae) Infecting Onychomys Species (Rodentia: Muridae) in New Mexico and Arizona

Fecal samples from 3 species of Onychomys (Rodentia: Muridae) captured in New Mexico and Arizona were examined for coccidia. Six of the 59 (10%) were infected with a new species of Eimeria. Sporulated oocysts (n = 105) of this new species are subspheroidal, 17.4 X 16.1 (14-21 X 13-19) μm, with ellipsoidal sporocysts 10.4 X 5.7 (9-12 X 5-8) μm. This species occurred in 3 of 24 (13%) Onychomys arenicola, 2 of 31 (6%) Onychomys leucogaster from New Mexico, and I of 4 (25%) Onychomys torridus from Arizona. Isolates recovered from O. leucogaster and O. torridus were inoculated into O. leucogaster (n = 5) and produced infections with a prepatent period of 7 days and a patent period of 7-23 days.