Survival potential and assessment of deformities in embryo and larvae of Chinese carps (Hypophthalmichthys molitrix and Ctenopharyngodon idella) under acute exposure of cadmium and nickel

The effects of cadmium (Cd) and nickel (Ni) toxicity on embryonic and larval development of Hypophthalmichthys molitrix and Ctenopharyngodon idella was determined. Different concentrations (0.1, 0.3, and 0.5 mg/l) of Cd and Ni were administered in separate trials to the fish after spawning to 168 h post-hatching (hph) period. Cd was more toxic to the embryos of both fish, as highest embryonic mortality (%) of H. molitrix and C. idella was observed. However, Ni was found to be more toxic to the larvae of H. molitrix and C. Idella with highest larval mortality at 168 hph. However, Ni was found to be more toxic to the larvae of H. molitrix and C. idella with highest larval mortality at 168 hph. The study found a significant effect of heavy metal and metal concentration for causing deformities in H. molitrix. However, in C. idella only the effect of metal concentration on fish deformities was significant. Furthermore, Ni was found to cause more deformities as compared to Cd in H. molitrix. While Cd was found to cause more deformities as compared to Ni in C. idella. In conclusion, the study suggests that Cd and Ni may cause serious deformities in fish.