Disinfection of Fertilized Grouper Eggs with Electrolyzed Seawater for Prevention of Viral Nervous Necrosis

Abstract

Conditions of fertilized egg disinfection with electrolyzed seawater were optimized to prevent vertical transmission of betanodavirus in longtooth grouper Epinephelus bruneus and sevenband grouper E. septemfasciatus. The treatments were performed by immersing eggs in electrolyzed seawater containing 0 to 1.5 mg/L of free chlorine. The conditions which showed no adverse effect on hatching rates of both species were 0.3 to 0.5 mg/L of free chlorine for 5 min, 1.0 mg/L for 3 min and 1.5 mg/L for 1 min. More than 99.4% of betanodavirus (SGNNV) was inactivated by the treatments of 0.3 to 1.0 mg/L of free chlorine for 3 min and 1.5 mg/L for 1 min.