Three cases with different types of short-tailed spermatozoa.

Short-tailed spermatozoa were found in 3 men attending our subfertility clinic. Light microscopy revealed basically normal sperm heads, but a short tail was found in 90% or more of the spermatozoa. Scanning and transmission electron-microscopic examinations of the ejaculate revealed several types of short-tailed spermatozoa. In one case, the majority of the spermatozoa had a short, thick tail. In another case, all the spermatozoa were short-tailed, although two different types could be distinguished. As in the first case some spermatozoa were short- and thick-tailed, whereas others possessed an incomplete neck and middle piece, and a short, thick principal piece. In the third case, an elongated middle piece and short principal piece were found in almost all the short-tailed spermatozoa. Our electron-microscopic study revealed that the type of short-tailed spermatozoa was different in each patient.