Effect of Disinfectants on Hatching of Fertilized Siniperca scherzeri Eggs

Effect of povidone-iodine, potassium permanganate or saline in varied concentrations on hatching of fertilized eggs of Siniperca scherzeri was studied. The eggs were submerged in a water bath containing one of the 3 substances in different concentrations at(23±1)℃ and pH(6.8±0.5)with a dissolved oxygen of (6.81±0.35)mg·L^-1. After soaking for 10 min, the egg-hatching rate and time were recorded for each treatment. The time and cycle in the povidone-iodine treatment group decreased gradually as the disinfectant concentration increased, and were significantly higher than those of control. Within the concentration of 30-50 mg·L^-1, the survival rate of hatched eggs was significantly higher than, but not significantly different on the deformity rate and hatching rate from, those of control. In the treatments using potassium permanganate with an increasing concentration, the hatching time was gradually shortened but longer than control, while the lower-than-control hatching rate increased initially but followed by a downward trend. There was no significant difference in deformity rate, but a significantly higher survival rate, as compared to control. For the saline treatments, 10 mg·L^-1 and 20 mg·L^-1 showed a significant higher hatching rate than either 40 mg·L^-1 treatment or control. No significant differences were observed on the hatching time, survival rate and deformity rate between the treatments and control. Thus, in Scherzeri breeding it was recommended the application of either 10% povidone-iodine solution in the concentration of 30-50 mg·L^-1 or saline in 10-20 mg·L^-1 to sanitize the eggs for 10 min be implemented to improve the hatchability. Since potassium permanganate is a strong oxidant, caution must be exercised in its application.