The Analysis of Clinical sign, Mortality and Histopathology of Cantang Grouper Infected with VNN in Recirculating Aquaculture System

Hybrid grouper is a variety of that has become increasingly popular in recent years. The development cultured Indonesia utilizing the Recirculating Aquaculture System (RAS) currently underway; nevertheless, fish RAS system continue to struggle with infectious diseases, one which VNN (viral nervous necrosis) infection caused by piscine betanodavirus. purpose this study was know clinical sign, mortality, and histopathology cantang (Epinephelus fuscoguttatus x E. lanceolatus) infected RAS. Fish samples were obtained from hatchery using This research uses mixed methods approach type used exploratory research. parameters observed signs, histopathology. Water quality, including temperature, DO, salinity, pH at time infection, as secondary data. results showed signs sick weakness, staying bottom rearing tank, decreased appetite, swimming stomach facing up body dark color. mortality occurred for ± 10 days peak reaching 26.86 7.45% on day 9 initial signs. Histopathology result, diseased vacuolization brain retina eye.