Effects of Four Commonly-Used Disinfectants on the Hatching of Fertilized Eggs of Epinephelus fuscoguttatus (♀)×E. lanceolatus (♂)

Abstract:

Disinfection of fertilized egg may prevent many pathogens and their vertical transmission; however, the toxic effects of disinfectants also exist. Therefore, it is important to control the type of disinfectants, their concentrations, and disinfection time. The current study investigated four commonly- used disinfectants on the hatching effects of Epinephelus fuscoguttatus(♀) × E. lanceolatus(♂) by bath method at (27±0.5)℃. Povidone-iodine, formaldehyde and chlorine dioxide treated for 10 min while Ozone treated for 1, 2 and 3 minutes respectively. The results indicated that the fertilized egg hatching and malformation rate were negatively associated with the concentrations of disinfectants and disinfection time. Formaldehyde and chlorine dioxide remarkably affected the hatching and malformation rate compared to those in the control group. Povidone-iodine had no effects on the hatching and malformation rate at 25 mg/L, 50 mg/L and 75 mg/L, but had significant effects at 100 mg/L. Ozone did not affect the hatching ability and malformations at 0.3 mg/L compared to the control group at all time points; and it had various influences at 0.5 mg/L, 0.7 mg/L and 1.0 mg/L of each time point. The hatching rate was extremely low (4.14%) and the deformity rate was 50.00% at 0.5 mg/L with 2-minute infection. These results suggest that the best condition for disinfection is as follows: povidone-iodine, 20–70 mg/L for 10 min; ozone, 0.3–0.5 mg/L for 1 min. Chlorine dioxide and formaldehyde are not recommended because of the side effects to the environment and humans.