1 Histopathological Effects of Sublethal Dose of Dichlorvos on Nerve Cord and Chloragogen Tissue of Eisenia fetida

Bulletin of Pure and Applied Sciences-Zoology (Started in 1982) 2020, Volume : 39, Issue : 1
First page : ( 1) Last page : ( 8)
Print ISSN : 0970-0765. Online ISSN : 2320-3188

1Yasha Yadav 2Vineeta Shukla*
1Lab- Animal Physiology and Toxicology, Department of Zoology, Maharshi Dayanand University, Rohtak, Haryana 124001, India.
2Department of Zoology, Maharshi Dayanand University, Rohtak, Haryana 124001, India
Correponding author email id: prof.vineetashukla@gmail.com

ABSTRACT

Dichlorvos or DDVP is an organophosphate pesticide which is used in agriculture rampantly, as well as in households and stored grain houses as an insecticide. While application, non target organisms in the soil may also get exposed to Dichlorvos. The persistence of residues of the pesticides is also a serious concern on the health of soilbiota. In present study, the effect of sublethal dose of the Dichlorvos was studied in earthworm Eiseniafetida. The worms were exposed to two sublethal doses of the pesticide for 7 and 14 days, subsequently, the worms were sacrificed and processed to prepare sections afterstaining and the changes in the nerve cord and chloragogen tissue were analyzed. By general observation, many behavioral changes were observed. Worms looked sluggish and showed excessive coiling. Histological changes in the peritoneum lining of the nerve cord were observed in the pesticide exposed worms. Changes in location of the giant fibres were also seen. Worms in control showed normal placement of the giant fibres, while in pesticide exposed worms, giant fibres appeared displaced. The muscle layer and epineurium also showed many changes compared to the control. Under exposure of Dichlorvos, Erosion of chloragogen tissue was seen. Significant vacuolization was also observed. The intestinal villi also were found to be eroded. Even at a sublethal dose, dichlorvos and other organophosphates can hamper the normal physiology of the soil biota such as earth worms and this can have detrimental effects on their survival and reproduction.

KEYWORDS
Diclorvos, Eiseniafetida, epineurium, giant nerve fibres, chloragogen tissue.