Phylogenetic Relationships and Historical Biogeography within the Enneacanthus Sunfishes (Perciformes: Centrarchidae)
The phylogenetic relationships within the Centrarchid genus Enneacanthus and the role of regional historical biogeography in their radiation was examined. Based on complete mitochondrial (mt) control region sequences, E. chaetodon is a monophyletic taxon that is sister to an ‘E. gloriosus + E. obesus’ clade. However, the current data indicate that E. gloriosus and E. obesus are not monophyletic taxa and appear to demonstrate either incomplete lineage sorting or a polyphyletic E. obesus. Based on molecular clock divergence estimates, the hypothesis of Pleistocene glacial cycles promoting speciation was not supported for either E. chaetodon or E. gloriosus, but is supported in having been a factor in the origins of E. obesus. Even though not a common force in terms of speciation, the Pleistocene oscillations do appear to have promoted subsequent diversification and dispersal (range expansion) for all three of these species.Abstract
Distributions of Enneacanthus sunfishes.
Collection locality map for the southeastern United States. Samples are labeled by state and site number.
Maximum parsimony (MP) majority rule consensus tree for Enneacanthus sunfishes with Lepomis and Perca as outgroups. The values shown on the branches are the resulting percentages of bootstrap analysis with 1000 pseudoreplicates. Distance scale provided indicates one bp change. Samples are labeled by state, site number, species, and individual, respectively, where species are coded as 1 for E. obesus, 2 for E. gloriosus, and 3 for E. chaetodon, e.g., ‘GA-6-2-5’ represents E. gloriosus specimen 5 from Georgia site 6 (GA-6). Number of individuals sampled of each haplotype per location are shown in parentheses following the sample label.
Contributor Notes
Associate Editor: J. M. Quattro.