Combined molecular and morphological phylogeny of Ephemerellinae (Ephemerellidae: Ephemeroptera), with remarks about classification

Abstract

This study represents the first combined molecular and morphological analysis for the mayfly family Ephemerellidae (Ephemeroptera), with a focus on the relationships of genera and species groups of the subfamily Ephemerellinae. The phylogeny was constructed based on DNA sequence data from 3 nuclear (18S rDNA, 28S rDNA, histone H3) and 2 mitochondrial (12S rDNA, 16S rDNA) genes, and 23 morphological characters. Taxon sampling for Ephemerellidae included exemplars from all 25 extant genus groups and additional representatives from those genera with the highest diversity. Ephemerellidae appears to consist of three major clades. Ephemerella, the largest genus of Ephemerellidae, and Serratella were not supported as monophyletic, and each had representatives in two of the three major clades. However, the genera Drunella and Cincticostella were supported as monophyletic. Lineages strongly supported as monophyletic include a grouping of the Timpanoginae genera Timpanoga, Dannella, Dentatella and Eurylophella, and groupings of the Ephemerellinae genera Torleya, Hyrtanella and Crinitella and the genera Kangella, Uracanthella and Teloganopsis. The placement of the Timpanoginae genus Attenella fell within Ephemerellinae, based on molecular and combined data, but it grouped with other Timpanoginae based on morphological data alone. Further study and analysis of Ephemerellidae morphology is needed, and classification should be revised, if it is to reflect phylogenetic relationships.