Complete maternal mitochondrial genome of the freshwater mussel (Bivalvia: Unionidae).

The genus Simpson, 1900 comprises seven valid species, and (Heude, 1874) is the type species of this genus. Previous phylogenetic studies using complete mitochondrial genomes showed that was not monophyletic, but the result was hampered by incomplete species sampling and lack of the type species of this genus. In this study, we collected from the type locality and determined its complete maternal mitochondrial genome. This mitogenome is 15,922 bp in length and contains 14 protein-coding genes (including one F-), two rRNA genes, 22 tRNA genes, and 1 putative control region. Our mitochondrial phylogenomic analysis confirms that currently recognized genus is polyphyletic, and is the closest to with high maximum likelihood bootstrap support value. Comprehensive sampling of all species is needed for phylogenetic analysis to erect new genera in future studies.