AFLP phylogeny of the snubnose darters and allies (Percidae: Etheostoma) provides resolution across multiple levels of divergence

Abstract

The snubnose darters (Percidae: subgenus Ulocentra) are a group of small, brightly colored North American freshwater fish belonging to the genus Etheostoma. Phylogenetic relationships among snubnose species have been a challenge to resolve at all levels of divergence, from the monophyly of species to deeper relationships among subgenera. Here, we used amplified fragment length polymorphisms (AFLPs) to estimate phylogenetic relationships among species from three closely related subgenera: Ulocentra, Etheostoma, and Nanostoma. With nearly complete sampling of recognized species, our analysis yielded a robust tree with statistical support at all nodes. Support was strongest for shallower relationships; support for internal nodes was either comparable to or greater than that of previous studies based on mitochondrial sequence data. Most recovered relationships were consistent with earlier hypotheses based on morphology or mtDNA sequences, with the exception of Etheostoma histrio, which was recovered as sister to Ulocentra. Our analysis indicates that careful use of AFLPs can yield statistically robust estimates of evolutionary relationships across multiple levels of divergence.