Morphology of the spermatozoon of a murid rodent from Africa, Dasymys incomtus

The structural organization of the head of the spermatozoon from the African murid rodent Dasymys incomtus was investigated by light and transmission electron microscopy and after incubation in various chemical agents. The results show that it is falciform in shape with a bifurcated rostral extension lying just caudal to the apical hook. The nucleus protrudes into the base of this extension but it is largely composed of a massive elaboration of the sperm head cytoskeleton which is very resistant to dispersion by chemical agents. This elaborate accessory structure of the sperm head shows similar morphology to the ventral processes on the sperm head of Australasian hydromyine rodents. The possible functional and evolutionary significance of these findings are discussed.W. G. Breed and N. Pilla