Cocoon production and viability as endpoints in toxicity testing of heavy metals with three earthworm species

This study compares the cocoon production and cocoon viability of three ear thworm species, Eudrilus eugeniae, Perionyx excavatus and Eisenia fetida af ter exposure to a sublethal concentration of lead nitrate. Cocoon productio n in all three species did not differ significantly between exposed and con trol worms. However, cocoon viability in all three species was affected det rimentally by the presence of lead nitrate. Cocoons of Eisenia fetida from substrates contaminated by lead nitrate, cadmium sulphate and zinc sulphate for 36 months, also showed a lowered cocoon viability. It is concluded tha t cocoon viability may be a sensitive endpoint of sublethal toxicity of the se metal salts.