The first complete mitochondrial genomes of subterranean dytiscid diving beetles (Limbodessus and Paroster) from calcrete aquifers of Western Australia

Comparative analyses of mitochondrial (mt) genomes may provide insights into the genetic changes, associated with metabolism, that occur when surface species adapt to living in underground habitats. Such analyses require comparisons among multiple independently evolved subterranean species, with the dytiscid beetle fauna from the calcrete archipelago of central Western Australia providing an outstanding model system to do this. Here, we present the first whole mt genomes from four subterranean dytiscid beetle species of the genera Limbodessus (L. palmulaoides) and Paroster (P. macrosturtensis, P. mesosturtensis and P. microsturtensis) and compare genome sequences with those from surface dytiscid species. The mt genomes were sequenced using a next-generation sequencing approach employing the Illumina Miseq system and assembled de novo. All four mt genomes are circular, ranging in size from 16 504 to 16 868 bp, and encode 37 genes and a control region. The overall structure (gene number, orientation and order) of the mt genomes is the same as that found in eight sequenced surface species, but with genome size variation resulting from length variation of intergenic regions and the control region. Our results provide a basis for future investigations of adaptive evolutionary changes that may occur in mt genes when species move underground.