Effect of zinc soil contamination on the survival of earthworms Aporrectodea caliginosa and effect on protein content and their tissues

This study aimed to evaluate the effects of zinc toxicity (750, 1000 and 1500 mg kg⁻¹) during periods (15 days) on worms (Aporrectodea caliginosa) collected from poultry breeding fields and effect on the protein content and the mortality rate. The highest mortality was (33%) at concentration 1500 mg kg⁻¹ and within 15 days of treatment. The histological sections showed that when the worms exposed to different concentrations of zinc, it resulted in shrinkage in the thickness of the body wall and bleeding under the epidermis and the presence of fragmentation, necrosis and contraction in the longitudinal muscle layer. The zinc metal reduces the proportion of protein in the body of worms in all concentrations, especially with increased concentration.Thus, this reduction in protein affects the diet of poultry and cows that add worms as nutrients in their diet to raise the level of protein in their bodies.