Surface disinfection of Atlantic halibut Hippoglossus hippoglossus eggs with ozonated sea-water inactivates nodavirus and increases survival of the larvae

[摘要] ABSTRACT: Disinfection by ozonation of sea-water may reduce the risk of transmission of nodavirus, a major fish pathogen, via Atlantic halibut Hippoglossus hippoglossus eggs. In the present study, eggs at 4 d prior to hatching were exposed tonodavirus and then to ozonated sea-water using different concentrations (0.3 to 10 mg l^-1) and exposure times (0.5 to 10 min). None of the larvae from virus-exposed eggs washed with ozonated sea-water developed viral encephalopathy andretinopathy (VER), which was detected in all dead larvae from eggs exposed to nodavirus but not washed with ozonated sea-water. In the non-treated control group about 20% of the dead larvae developed the disease. This suggests that the halibut eggs takenfrom a large-scale production facility were already contaminated with nodavirus. The egg groups which had been treated with 4 mg O₃ l^-1 for 0.5 min or with lower total ozone exposures had a higher survival and no adverse effects onthe development of the larvae after hatching were observed. Although a slight delay in hatching was found, after 2 d the cumulative hatching had normalised. In the egg groups with high total exposure (4 mg O₃ l^-1 for 1 min or highertotal ozone exposures) a pronounced negative effect on hatching was observed. Our results indicate that the egg surface may be important in the transfer of nodavirus and that nodavirus associated with the surface of the egg may be inactivated by ozonatedsea-water.

[学科分类] 生物科学（综合）

[关键词] Atlantic halibut;Fish egg;Ozonation;Egg disinfection;Aquaculture techniques;Nodavirus;Atlantic halibut;Viral encephalopathy and retinopathy (VER)