Characterization of the Complete Mitochondrial Genome and Phylogenetic Analyses of (Trematoda: Dicrocoeliidae).

, a pancreatic fluke, is recognized as a causative agent of substantial economic losses in ruminants. This infection, commonly referred to as eurytrematosis, is a significant concern due to its detrimental impact on livestock production. However, there is a paucity of knowledge regarding the mitochondrial genome of . In this study, we performed the initial sequencing of the complete mitochondrial genome of . Our findings unveiled that the mitochondrial genome of spans a length of 15,831 bp and consists of 12 protein-coding genes, 22 tRNA genes, two rRNA genes, and two noncoding regions. The A+T content constituted 62.49% of the genome. Moreover, all 12 protein-coding genes of exhibit the same arrangement as those of and other published species belonging to the family Dicrocoeliidae. The presence of a short string of additional amino acids (approximately 20~23 aa) at the N-terminal of the cox1 protein in both and mitochondrial genomes has contributed to the elongation of the gene in genus , surpassing that of all previously sequenced Dicrocoeliidae. The phylogenetic analysis displayed a close relationship between and , along with a genus-level association between and . These findings underscore the importance of mitochondrial genomic data for comparative studies of Dicrocoeliidae and even Digenea, offering valuable DNA markers for future investigations in the systematic, epidemiological, and population genetic studies of this parasite and other digenean trematodes.