Minnows and molecules: resolving the broad and fine-scale evolutionary patterns of Cypriniformes

Abstract

Cypriniformes (minnows, carps, loaches, and suckers) is the largest group of freshwater fishes in the world. Despite much attention, previous attempts to elucidate relationships using molecular and morphological characters have been incongruent. The goal of this dissertation is to provide robust support for relationships at various taxonomic levels within Cypriniformes. For the entire order, an anchored hybrid enrichment approach was used to resolve relationships. This resulted in a phylogeny that is largely congruent with previous multilocus phylogenies, but has much stronger support. For members of Leuciscidae, the relationships established using anchored hybrid enrichment were used to estimate divergence times in an attempt to make inferences about their biogeographic history. The predominant lineage of the leuciscids in North America were determined to have entered North America through Beringia ~37 million years ago while the ancestor of the Golden Shiner (Notemigonus crysoleucas) entered ~20–6 million years ago, likely from Europe. Within Leuciscidae, the shiner clade represents genera with much historical taxonomic turbidity. Targeted sequence capture was used to establish relationships in order to inform taxonomic revisions for the clade. Presented is a revised, genus-level taxonomy for the group. Finally, for Notropis longirostris (now Miniellus longirostris), genetic analyses using mtDNA found four distinct, unconnected haplotype networks across its southeastern USA range with high genetic divergence, despite a lack of morphological differentiation.