Effects of Copper Oxide Nanoparticles (CuO-NPs) on Parturition Time, Survival Rate and Reproductive Success of Guppy Fish, Poecilia reticulata

The purpose of the present study was to evaluate acute and chronic effects of CuO-NPs on survival rate and reproductive success of mature guppy (Poecilia reticulata) and their larvae. During the acute toxicity test, mature fish and their larvae were exposed to series of different concentrations of (0, 5, 10, 15, 20, 25, 30, 35, 40 and 45 mg L-1) CuO-NPs for 96 h and during the chronic phase we exposed mature individuals to 0, 5, 10 mg L-1 of CuO-NPs for 8 weeks. Results showed a significant correlation between mortality rate and CuO-NPs concentrations. Furthermore, the LC50 96 h of CuO-NP for mature and larvae of P. reticulata were 28.354 and 5.649 mg L-1, respectively. Finally, the fish exposed to series of CuO-NP concentrations exhibited various clinical signs such as darkening of skin, anxiety and death with open mouth. Chronic exposure affected reproductive traits of fish, with greatest effects reported in treatment with 10 mg L-1 of CuO-NPs. Those individuals had lowest reproductive success, prolonged parturition time and highest mortality rate. Results highlight toxic potential of CuO-NPs on mature and larvae fish, both increased mortality rate and lower reproductive success, by increasing parturition time and reducing number of larvae.