Neighbor joining trees of the freshwater eel Rh1 (A), Rh2 (B), and SWS2 (C) opsin and (D) <i>cytochrome b</i> genes based on Maxima-likelihood distances.

<p>The scale bar represents 0.05 nucleotide substitutions. The nucleotide sequences of fish opsin genes were obtained from GenBank. The genes and their accession numbers are listed in Table S3. ^a λ_max of rod cells from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103953#pone-0103953-t001" target="_blank">Table 1</a> & <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103953#pone-0103953-t006" target="_blank">Table 6</a>. ^b λ_max of rod cells from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103953#pone.0103953-Wood2" target="_blank">[15]</a>. ^c λ_max of rod cells from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103953#pone.0103953-Beatty1" target="_blank">[12]</a>. ^d λ_max of rod cells from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103953#pone.0103953-Shapley1" target="_blank">[71]</a>. ^e λ_max of rod cells from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103953#pone.0103953-Wang3" target="_blank">[65]</a>.