THE INFLUENCE OF ATRAZINE ON THE REPRODUCTIVE POTENTIAL OF Eisenia foetida (Oligochaeta)

Abstract

In addition to their carcinogenic or mutagenic capabilities, pesticides and toxic industrial wastes may have profound effects on wildlife reproduction by mimicking the female hormone estrogen. It is believed that hormonal feminization is widespread in the animal kingdom and could even affect human health and reproduction. Although many of these chemicals are controlled, restricted or banned, even small amounts already present in the environment could have adverse effects for decades. Many pesticides used in modern agriculture are believed to belong to a family of estrogenic chemicals. Following range-finding toxicity tests, a laboratory experiment was conducted using sublethal doses of AAtrex, a formulation of the agricultural herbicide atrazine, to examine potential reproductive effects on the earthworm Eisenia foetida. Because of their direct contact with the soil, earthworms are ideal nontarget organisms for pesticide testing. Increased concentrations of atrazine resulted in greater weight loss in worms. Higher levels of atrazine had a negative effect on the ratio of combined weight of the male reproductive organs to the worm's final body mass at the conclusion of the experiment. Increased atrazine concentrations also had a negative impact on sperm density within the seminal vesicles and testes compared to their organ weights. Numbers of cocoons produced and cocoon hatching success were also adversely affected. The results indicate that atrazine could very well be an environmental hazard for the earthworm E. foe tida by greatly reducing its reproductive potential. A reduction in earthworm populations results in lower soil fertility. Knowledge of such "non-lethal" pesticide effects has great predictive value in examining reproductive disturbances in many other beneficial soil invertebrate species.