Phylogenetic Analysis with Complete Mitochondrial Genome Sequences of Benedenia seriolae Specimens Derived from Japanese Seriola spp.

― Infection with the skin fluke Benedenia seriolae is a serious threat of yellowtail aquaculture. Development of genomic resources and molecular markers for B. seriolae is an essential infrastructure to develop control strategies against B. seriolae infections. As a seminal study to establish the genomic resources of the Japanese B. seriolae populations, we sequenced the complete mitochondrial genome (mitogenome) sequences of 12 B. seriolae specimens collected from four prefectures in Japan. The Japanese B. seriolae mitogenomes were mutually 99% identical, while the identity was 85% when compared to that of an Australian specimen. Furthermore, the gene arrangement in the Japanese B. seriolae mitogenome was slightly different from that in the Australian specimen. The substantial mitogenomic divergence between the Australian and Japanese specimens indicates that B. seriolae is composed of molecularly divergent populations. Variable sites were dispersed in the mitogenome of the Japanese B. seriolae . Phylogenetic relationships among the Japanese B. seriolae specimens did not reflect the host species or geographic distributions within Japan.