THE INFLUENCE OF LEAD AND MANGANESE ON SPERMATOZOA OF EISENIA-FETIDA (OLIGOCHAETA)

The effects of lead and manganese on the spermatozoan ultrastructure o f Eisenia fetida were studied by feeding pre-clitellate worms in labor atory cultures weekly with fresh, urine-free cattle manure containing sublethal quantities of the heavy metal compounds for 8 weeks. The wor ms were analysed for heavy metal content after eight weeks, and electr on microscopical observations of spermatozoa of exposed and control wo rms were performed. The body loads of heavy metals in the worms at the end of the observation period were 41.8 mu g g(-1) (0.20 mu mol g(-1) ) and 9.3 mu g g(-1) (0.17 mu mol g(-1)) for Pb and Mn respectively, p ossibly indicating differential accumulation of the two metals since h igher dosages of Pb were given. Electron microscopical observations sh owed marked cellular damage to the spermatozoa from worms exposed to t he heavy metals, compared to the sperm cells from the control worms. S tructural damage of spermatozoa included breakage and loss of nuclear and flagellar membranes, thickening of membranes, malformed acrosomes and loss of nuclear material. The fact that the spermatozoa were adver sely affected by sublethal concentrations of certain heavy metals, rai ses the possibility of utilizing this phenomenon in toxicity testing. (C) 1997 Elsevier Science Ltd.