The mitochondrial genome of Polylabris halichoeres (Monogenea: Microcotylidae).

This study presents the complete mitochondrial (mt) genome of Polylabris halichoeres, which is the largest mt genome sequenced of monogeneans so far and the second complete sequence after Microcotyle sebastis from the Microcotylidae. It is basically similar to that of M. sebastis, with the exception of a high level of gene rearrangement located between trnC and trnL((UUR)), a translocation of trnM and trnH, as well as a highly repetitive region (HRR) in the large non-coding region (NCR). We also find a series of trnI pseudogenes (ΨI) and one unknown short open reading frame (ORF) in the large NCR. Although the ORF cannot be unambiguously regarded as an atp8 gene, we cannot rule out the possibility that it has other functional importance, but it need further study in the future.