Gametes in late stages of spermiogenesis are closely packed in numbers approximating 64 in mutant males. The axoneme and the major and minor mitochondrial derivatives develop normally to a late stage. The heads of the spermatids also appear to develop normally to a late stage, and they enter the coiling process. The axoneme seems less stable than normal; axoneme degeneration is seen in some gametes in the elongating process and in cysts in which the gametes are indiviualised and, apparently, coil. Some late stage spermatids share a common cell membrane, indicating that individualisation has been abnormal.

Testes of mutant males contain a few motile sperm, but none are transferred to females during copulation.