Phylogenetic analysis of Jenynsia onca opsins. A neighbour-joining bootstrap tree, which uses opsin coding sequence from J. onca and relatives. The percentage of trees in which the associated taxa clustered together in the bootstrap test (1000 replicates) is reported at the nodes. PAUP* 4.0B10 was used to estimate genetic distances, based on modeltest's best-fit model of evolution, and complete phylogenetic analysis [18, 19] [accession numbers see Additional file 3]. All codon positions were included. Pair-wise deletion was used in the case of missing nucleotides for the analysis.