TL;DR: Phylogenetic reconstructions converged on a single, highly supported tree in which Neritopsoidea was recovered as the sister group of a clade including Helicinoidea as the siblings of Hydrocenoidea and Neritoidea, which agrees with the fossil record and supports at least three independent invasions of land by neritimorph snails.
TL;DR: The complete mitochondrial genome of the stream neritid Clithon retropictus was determined by next-generation sequencing, marking the first report of a complete mitochondrial sequence for the genus and the fourth for the gastropod subclass Neritimorpha.
Abstract: The complete mitochondrial genome of the stream neritid Clithon retropictus was determined by next-generation sequencing. The mitochondrial genome is 15,814 bp in length, comprising two ribosomal RNA genes, 13 protein-coding genes (PCGs) and 22 transfer RNA genes (tRNAs). Of these 37 genes identified, 7 PCGs and 8 tRNAs are encoded on the heavy strand and the other genes on the light strand. This gene order is consistent with the previously published mitochondrial genomes of the other neritid species. This is the first report of a complete mitochondrial genome sequence for the genus and the fourth for the gastropod subclass Neritimorpha.