Toxic effects of benomyl on the ultrastructure during spermatogenesis of the earthworm Eisenia fetida.

The present study has investigated the toxic effect of benomyl on the ultrastructure of the male reproductive system and spermatozoa of the earthworm Eiseniafetida in a laboratory experiment. Three different concentrations of benomyl (8.3, 56, 112 mg/kg dry soil) were applied for one week. These applications caused abnormalities in ultrastructure of the cytophore, the spermatogonia, spermatids, and spermatozoa. The alterations include uncomplete forms of acrosomes, nuclear distortion, and disruption of microtubules. These micromorphological changes should be included in a model for predicting environmental hazards.