Investigations of enzymatically isolated male Onchocerca volvulus: qualitative and quantitative aspects of spermatogenesis.

A simple technique for the identification of the different spermatogenetic stages of Onchocerca volvulus is described. It is practicable for large-scale examinations in the field. The reproductivity of male worm populations can be assessed and directly correlated with the corresponding female worm populations. The activity of male filariae decreases with the increasing age of the worm population. Only few male worms transmit spermatozoa during mating, but spermatogenesis is continous also in very old male individuals. These old male filariae store high numbers of spermatozoa and cease their migration between the nodules.