2.3. Mitochondrial genome annotation
These two mtDNAs were assembled manually, and annotated preliminarily by Geseq (https://chlorobox.mpimp-golm.mpg.de/geseq.html) with the reference of related species, T. pisiformis and T. crassiceps , identified by the cox 1 gene alignment of Neighbor-Joining method in MEGA 5.1 (data not show). Putative tRNA genes were identified using ARWEN (http://130.235.46.10/ARWEN/) (Laslett & Canbäck, 2008). The positions of their open reading frames and rRNA genes were also further checked and modified based on alignment with the mt genomes annotation of T. pisiformis and T. crassiceps , respectively. SnapGene (v3.2.1) was used to translate the amino acid sequence of the protein-coding genes with genetic code of the Echinoderm, Flatworm Mitochondrial and map the annular diagram of the mt genomes.