EIMERIA-RHEEMI SP-N (APICOMPLEXA, EIMERIIDAE) FROM THE ARABIAN SAND GAZELLE, GAZELLA SUBGUTTUROSA-MARICA (ARTIODACTYLA, BOVIDAE) IN SAUDI-ARABIA

Oocysts of Eimeria rheemi sp. n. were detected in the feces of 35 out of 73 (48%) rheem or Arabian sand gazelles, Gazella subgutturosa marica Thomas, 1897, examined at King Khalid Wildlife Research Center, Thumamah, Riyadh Province, Saudi Arabia. Sporulated oocysts of E. rheemi sp. n. are spherical or ovoid, 25 x 21 (20-34 x 18-30) mu-m, with smooth, double-layered wall and micropyle, but no micropylar cap. The outer oocyst layer is yellow, almost twice as thick as the bluish-green inner one. Sporocysts oval, 10 x 8 (6-15 x 5-10) mu-m, each with a Stieda body and residuum. Sporozoites elongate 9 (7-11) mu-m, each with a single refractile globule 3 (2-4) mu-m in diameter at the wider end. Sporulation time 24 hr at 25 +/- 2-degrees-C in aqueous K2Cr2O7. Eimeria rheemi sp. n. is pathogenic to young rheem (2-4 mo old) causing mild to severe mucoid diarrhea, commensurate with the fecal oocyst count and has responded well to sulphonamide treatment.