Neighbour-joining (NJ) phylogenetic trees. (a) partial RNA1-based phylogeny. (b) partial RNA2-based phylogeny. Strains isolated from wild diseased golden grouper, dusky grouper and European sea bass are labelled in blue, while betanodaviruses detected in farmed European sea bass reared in close proximity of the epidemic area are labelled in red. The numbers at branch points represent bootstrap values expressed as percentages (only values ≥ 70 are reported). The genotype subdivision according to Nishizawa et al.,  is shown at the main branches. Scale bar represents nucleotide substitutions per site.