^aErythrocytic viruses, which are antigenically unrelated to ranaviruses and are not associated with amphibian mass deaths or declines, are not included. Further work is required to evaluate their significance.
^bThere is little variation in the major capsid protein (a major antigen of this group of viruses) within the genus Ranavirus (<4% difference at the nucleotide and amino acid level; Hyatt, unpubl. obs). This high degree of homology is interesting, as some of these viruses do not appear to be species specific. No discriminating neutralizing antibodies exist, and ranaviruses are identified and characterized by a range of techniques, including antigen capture enzyme-linked immunosorbent assay, polyacrylamide gel electrophoresis, restriction endonuclease digestion, polymerase chain reaction, and sequencing and in situ hybridization (67,71).
^cWhere no name has been given, the virus has not yet been named.