Dr. Holló Ferenc szerk.: Parasitologia Hungarica 4. (Budapest, 1971)
The four sporocysts are usually arranged with three in one plane and the fourth lying on them, or so that two pairs of parallel sporocysts cross each other. The rough granules of the sporocysts residuum are dispersed in the several sporocysts, at other times condensed centrally. The sporozoites are banana-shaped , with measurements 8.5 x 2— 2.5/t, their more tapered extremity sometimes slightly recurved. They arrange head-to-tail along the more convex side of the sporocyst, the remaining space being filled by sporocysts residuum. At extremity of sporozoites with a smaller and nearer to the wider end with a larger paranuclear body. No coccidium has hithero been described from the ruff. The coccidia described from the closely related fresh-water Perciformes differ decidedly in their morphology from the new species. The oocysts of Eimeria cotti and E. piraudi (host: Gottus gobio), of approximately similar dimensions, differ in that the sporocysts of the former species possess a neck-like cerviform extension, whereas the oocyst wall of E. piraudi is not thin but thick, and one end of the sporocysts is moderately tapered. The oocysts of E. percae , which parasitizes Perca fluviatilis, have a micropyle and there is a corresponding thickening of the cyst wall. Among the coccidia of phylogenetically more distant fish species it is the oocysts of E. cyprinorum , parasitizing species of the order Cypriniformes , with most nearly resemble those of the new species, but then only to a certain extent, as they too differ in that the sporozoites recurve hookwise uncinately within the sporocysts.
