Mitochondrial genome of the polychaete Tylorrhynchus heterochaetus (Phyllodocida, Nereididae).

We firstly reported the complete mitochondrial genome (mitogenome) of the polychaete Tylorrhynchus heterochaetus. Illumina next-generation sequencing generated a total of 19,796 reads with an average depth of 122.91×. The mitogenome is 16,106 bp in length including the typical structure of 13 protein coding genes, two rRNA genes, 22 tRNA genes and a putative control region. However, T. heterochaetus differs from other Nereididae species in the positions of four genes (tRNA-Met, tRNA-Asp, ATP8, tRNA-Tyr). All 37 genes are encoded on the heavy strand whose nucleotide composition is 32.20 % A, 13.67% C, 21.33% G and 32.80% T.