The Toxicity of Imidacloprid on Early Embryonic Stages and Growth Rate of Hatchlings of Common Carp, <i>Cyprinus carpio</i>

Abstract

In the present investigation, the toxicity of imidacloprid was tested on the embryos (fertilized eggs) and hatchlings of Cyprinus carpio in terms of mortality (%), hatching success (%) and abnormal/malformed hatchling along with their growth performance in toxicant medium. Reported data from acute toxicity tests of imidacloprid was statistically analyzed by Probit Analysis Method and 48 h (hour) LC50 was reported as 78 ppm for embryos of C. carpio. Three sublethal doses of imidacloprid i.e., 7.8 ppm (T1), 15.6 ppm (T2) and 23.4 ppm (T2), were selected for further experimentation along with control. The findings revealed that mortality of exposed eggs (%) was significantly (p<0.05) increased in dose dependent manner as a result hatching rate (%) was decreased as compared to control. Similarly, per cent of abnormal hatchling was also increased significantly (p<0.05) with increase in pesticide concentration. Various types of abnormalities has been reported in different body regions such as whole length curved body, stunted growth, hatchling with single eye, malformed head, flexure in the tail and deformed yolk sac etc. Growth rate was observed as length gain in centimeter (cm), weight gain in grams (g) and growth per cent gain in body weight of hatchling, which was also found to be declined significantly (p<0.05) with increase in pesticide concentration. The findings of the present investigation suggest that imidacloprid has significant effect on the early developmental stages, induces malformations and also decline the growth rate of hatchlings.