Parasitology, Harold W. Manter Laboratory of
Date of this Version
2-1973
Abstract
Oocysts of Eimeria banffensis Lepp, Todd, and Samuel, 1972, Eimeria cryptobarretti sp. n., Eimeria princepsis sp. n., and Eimeria calentinei sp. n. are described from the Colorado pika, Ochotona princeps, collected from 3 mountain sites in Colorado. Subspherical oocysts of E. banffensis measure 23 to 34 by 18 to 25 μ (mean 27.6 by 23.0 μ) with ovoid sporocysts 10 to 16 by 7 to 10 μ (mean 12.5 by 8.5 μ). A micropyle, oocyst residuum, and polar granule are absent, but a sporocyst residuum, Stieda body, and substiedal body are present. The ellipsoidal oocysts of E. cryptobarretti measure 24 to 35 by 18 to 22 μ (mean 29.8 by 20.6 μ) with distinct, elongate bulb-shaped sporocysts 13 to 18 by 7 to 11 μ (mean 15.2 by 8.4 μ). A micropyle, sporocyst residuum, and Stieda body are present, but a polar granule and oocyst residuum are absent. Ellipsoidal oocysts of E. princepsis measure 19 to 24 by 15 to 19 μ (mean 21.5 by 17.3 μ) with ovoid sporocysts 10 to 14 by 5 to 8 μ (mean 12.3 by 7.3 μ). A micropyle, polar granule, sporocyst residuum, and Stieda body are present, but an oocyst residuum is absent. Ovoid oocysts of E. calentinei measure 26 to 32 by 18 to 23 μ (mean 28.5 by 20.0 μ) with ovoid sporocysts 10 to 14 by 6 to 9 μ (mean 12.0 by 7.4 μ). A polar granule is absent, but a micropyle, oocyst and sporocyst residuum, and Stieda body are present. The in vitro excystation of sporozoites of E. cryptobarretti and E, calentinei is described. Sporozoites of E. banffensis and E, princepsis did not excyst after exposure to the excysting fluid for 60 min. Possible reasons for this are discussed.