The complete mitochondrial genome of Potomida acarnanica (Kobelt, 1879)

Abstract

Freshwater mussels (Bivalvia, Unionida) play essential roles in the well-functioning of ecosystems, even providing essential services to humans. However, these bivalves face numerous threats (e.g. habitat loss and fragmentation, pollution, introduction of invasive species, and climate change) which have already led to the extinction of many populations. This underscores the need to fully characterize the biology of these species, particularly those, such as Potomida acarnanica, that are still poorly studied. This study presents the first mitogenome of P. acarnanica (Kobelt, 1879), an endemic species of Greece with a distribution limited to only two river basins. The mitochondrial genome of a P. acarnanica specimen, collected at Pamisos River (Peloponnese, Greece), was sequenced by Illumina high-throughput sequencing. This mitogenome (16,101 bp) is characterized by 13 protein-coding genes, 22 transfer RNA and 2 ribosomal RNA genes. The size of this mitogenome is within the range of another Potomida mitogenome already published for the species Potomida littoralis. In the phylogenetic inference, P. acarnanica was recovered as monophyletic with P. littoralis mitogenome in the Lamprotulini tribe, as expected. This genomic resource will assist in genetically characterizing the species, potentially benefiting future evolutionary studies and conservation efforts.

Keywords: Mitogenome; freshwater mussels; phylogeny.

Figure 1.

Species image reference of P. acarnanica (photograph by Manuel Lopes-Lima).

Figure 2.

Mitogenome map of P. acarnanica. This plot was created with the annotation model of MITOZ. The outermost track displays the gene features and their strand positioning on the assembly. The color scheme are red for tRNA, green for PCGs, and orange for rRNAs. The Middle track represents read depth distribution across the assembly. The innermost track represents GC content distribution across the assembly.

Figure 3.

Maximum Likelihood Phylogenetic inference with all the downloaded mitogenomes (n = 19) and with the new mitochondrial genome of P. acarnanica (this mitogenome has been deposited in Genbank with accession number PP035751). The mitogenomes used in this phylogeny were: Sinohyriopsis schlegelii (NC_015110.1) (Sheng et al. 2014), Sinohyriopsis cumingii (NC_011763.1) (unpublished), Chamberlainia somsakpanhai (NC_044110.1) (Froufe et al. 2020), Physunio superbus (MW242814.1) (Zieritz et al. 2021), Lens contradens (MW242812.1) (Zieritz et al. 2021), Hyriopsis bialata (MW242816.1) (Zieritz et al. 2021), Rectidens sumatrensis (MW242818.1) (Zieritz et al. 2021), Sinosolenaia carinata (NC_023250.1) (Huang et al. 2013), Sinosolenaia oleivora (NC_022701.1) (Huang et al. 2015), Microcondylaea bonellii (NC_044111.1) (Froufe et al. 2020), Parvasolenaia rivularis (NC_039839.1) (unpublished), Pseudodon vondembuschianus (NC_044112.1) (Froufe et al. 2020), Pilsbryoconcha linguaeformis (NC_044124.1) (Froufe et al. 2020), Potomida littoralis (NC_030073.1) (Froufe et al. 2016), Pronodularia japanensis (AB055625.1) (unpublished), Lamprotula leaii (NC_023346.1) (unpublished) and Lamprotula caveata (NC_030336.1) (unpublished). The two outgroup taxa used were: Amblema plicata (NC_050056.1) (Teiga-Teixeira et al. 2020) and M. margaritifera (NC_043836.1) (Gomes-dos-Santos et al. 2019).