Molecular Phylogenetics of the Chub Suckers (Teleostei: Catostomidae: Erimyzon) Inferred from Nuclear and Mitochondrial Loci
Phylogenetic relationships among the four currently recognized species in the genus Erimyzon were reconstructed using sequence data obtained from the mitochondrially encoded COI and the nuclear-encoded IRBP2 genes. Maximum likelihood and Bayesian analyses yielded five groups of Erimyzon. Three of the clades corresponded to the species E. oblongus, E. tenuis, and E. claviformis. Individuals identified as E. sucetta were split into two separate clades, with one clade more closely related to E. oblongus than to the other E. sucetta clade in three of four analyses. Two instances of putative hybridization between sympatrically distributed species were also detected, one involving E. oblongus and E. sucetta and the other involving E. claviformis and E. tenuis. The results suggest that the currently recognized E. sucetta comprises two species, with potentially non-overlapping distributions. Further morphological investigation is warranted to provide additional support for recognizing this putative fifth species of Erimyzon.
Maps showing locations where tissue samples from each species (circle E. claviformis, square E. oblongus, triangle E. sucetta, open circle E. tenuis) were acquired and the described distribution of each species (modified from Page and Burr, 2011; map A: E. sucetta and E. oblongus, map B: E. claviformis and E. tenuis).
COI genetree of Erimyzon inferred from maximum-likelihood analysis using RAxML v.8.02. Values at nodes represent bootstrap support. State abbreviations: AL, Alabama; FL, Florida; LA, Louisiana; NC, North Carolina; NY, New York; OH, Ohio; ON, Ontario, Canada; SC, South Carolina; TN, Tennessee; TX, Texas; VA, Virginia. See Data Accessibility for tree file.
COI genetree of Erimyzon inferred from Bayesian analysis, using Beast v2.5. Values at nodes represent posterior probability support. State abbreviations: AL, Alabama; FL, Florida; LA, Louisiana; NC, North Carolina; NY, New York; OH, Ohio; ON, Ontario, Canada; SC, South Carolina; TN, Tennessee; TX, Texas; VA, Virginia. See Data Accessibility for tree file.
IRBP2 genetree of Erimyzon inferred from maximum-likelihood analysis, using RAxML v.8.02. Values at nodes represent bootstrap support. State abbreviations: AL, Alabama; FL, Florida; LA, Louisiana; NC, North Carolina; NY, New York; OH, Ohio; ON, Ontario, Canada; SC, South Carolina; TN, Tennessee; TX, Texas; VA, Virginia. See Data Accessibility for tree file.
IRBP2 genetree of Erimyzon inferred from Bayesian analysis, using Beast v2.5. Values at nodes represent posterior probability support. State abbreviations: AL, Alabama; FL, Florida; LA, Louisiana; NC, North Carolina; NY, New York; OH, Ohio; ON, Ontario, Canada; SC, South Carolina; TN, Tennessee; TX, Texas; VA, Virginia. See Data Accessibility for tree file.
Contributor Notes
Associate Editor: D. Buth.