title: Rouleaux formation by spermatozoa in the naked-tail armadillo, Cabassous unicinctus.
abstract: Spermatozoa from the ductus deferens of a naked-tail armadillo, Cabassous unicinctus, were arranged in rouleaux. The sperm heads were wafer-thin, with the acrosome and nucleus flattened together. Dense subacrosomal material in the equatorial segment of the acrosomal region was present on one surface but not on the other.
mesh_terms: D000818:Animals; D001135:Armadillos / Q000502:physiology*; D008297:Male; D008858:Microscopy, Phase-Contrast; D013094:Spermatozoa / Q000648:ultrastructure*; D004490:Xenarthra / Q000502:physiology*