Dimensions of sporulated oocysts representing Eimeria collected from domestic chickens (Gallus gallus domesticus). (A) Oocysts from all seven Eimeria spp. that infect chickens and Operational Taxonomic Units (OTUs) x, y, and z. For close comparison subsets of (B) Eimeria maxima and OTUx, (C) Eimeria brunetti and OTUy, and (D) Eimeria acervulina, Eimeria mitis, and OTUz, are shown. Note: The scales used vary between panels to improve illustration of differences between oocysts with closely comparable dimensions.