Genetic characterization of betanodavirus isolates from Asian seabass Lates calcarifer (Bloch) in India.

Betanodavirus has been detected in Asian seabass in India. Molecular characterization of the isolates on the basis of the full-length viral RNA2 sequence was performed. Subsequent phylogenetic analysis with sequences from members of the four species in the genus Betanodavirus revealed that the present isolates are closely related to members of the species Redspotted grouper nervous necrosis virus. The analysis also revealed that the RNA2 sequence was not responsible for acute symptoms in seabass. This is the first attempt to characterize Indian isolates of fish nodaviruses, and the result will be useful for devising specific control and health-management strategies for this virus.