A NEW AND UNUSUAL EIMERIAN (PROTOZOA: EIMERIIDAE) FROM THE LIVER OF THE GULF KILLIFISH, Fundulus grandis

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Abstract
Oocysts and sporocysts of E. funduli sp. nov. are described from the Gulf killifish, F. grandis, on the basis of light microscopy, transmission and scanning EM and location in the liver of infected hosts. Spherical sporulated oocysts of E. funduli isolated from liver tissue measure 20-31 (25) .mu.m across with ovoid sporocysts 9-11 .times. 5-7 (10 .times. 6) .mu.m. Micropyle, polar granule and oocyst residuum are absent, but sporocysts have Stieda and substieda bodies, a few residual granules and 10-25 (15) unique projecting structures with expanded distal portions that are termed sporopodia. Sporopodia 1-3 (2) .mu.m high support a transparent membrane that completely surrounds the sporocyst. Sporozoites have 1 large posterior refractile body. Ultrastructurally, the oocyst wall consists of 2 thin layers of granular material, an electron-dense outer layer with a rough external surface and an electron-lucent inner one of approximately equal thickness. One or 2 unit membranes line the inner surface of the inner layer. Each layer is 40-60 (55) nm thick. The sporocyst wall, 78-130 (110) nm thick, consists of an electron-lucent material with the outer surface being more electron dense and giving rise to osmiophilic sporopodia; closely associated with these and the outer surface are 1 or 2 unit membranes. A thin osmiophilic layer of fine granular material lines the inner surface.