Phylogenetic analysis. (A) The phylogenetic analysis based on the RNA dependent RNA polymerase of Reoviridae. The phylogenetic tree was constructed using the neighbor-joining method in MEGA 4.0. Numbers of the genome segments and hosts of each genus are shown. Two subfamilies, Spinareovirinae and Sedoreovirinae, were divided by a skewed broken line. (B) The phylogenetic analysis of the major outer capsid protein VP7 from aquareovirus species was carried out as in materials and methods. The numbers given are frequencies (%) at which a given branch appeared in 1000 bootstrap replications. Viruses appearing above the broken line are from hosts that had seawater life-histories and viruses from hosts that lived in fresh water are listed below the broken line. GenBank accession numbers were collected in additional file 2 and 3.