The complete mitochondrial genome sequence of the network pipefish (Corythoichthys flavofasciatus) and the analyses of phylogenetic relationships within the Syngnathidae species.

This study determined the mitochondrial genome sequence of the network pipefish (Corythoichthys flavofasciatus) (Gasterosteiformes: Syngnathidae). The mitogenome was a circular molecule consisting of 16,961 nucleotides, including 13 protein-coding genes, 22 tRNA genes, two rRNA genes and a control region. The nucleotide composition of the genome was biased toward A+T content at 59.3%. All tRNA genes had typical cloverleaf secondary structure except for tRNA(Ser (AGY)), in which the dihydrouridine arm was missing. The C. flavofasciatus control region of 1130 bp contained several features common to other teleost, including conserved sequence blocks. We also performed comparative analysis of the network pipefish mitogenome to the available mitogenome sequences of other Syngnathidae species, and phylogenetic relationship of the Syngnathidae species was constructed based on the data sets including all the concatenated nucleotide sequences of the mitogenomes except the third codon positions. Partitioned Bayesian inference and maximum likelihood analyses showed that all seahorse species formed a monophyletic group of Hippocampus with 100% PPs and BPs, but the pipefish species did not form a monophyletic group. Corythoichthys flavofasciatus was placed as a sister relationship to the Hippocampus clade by strong node-supporting values. The availability of mitogenome of the network pipefish will shed light on the molecular systematics, biogeography and genetic differentiation in this species.