Abstract
This study reports the first complete mitochondrial genome of Opsariichthys jishuiensis. The circular genome (16,614 bp) contains 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and a control region. Phylogenetic analysis using Bayesian inference and maximum-likelihood methods identifies O. jishuiensis as most closely related to O. acutipinnis and O. evolans, forming a monophyletic clade within the subfamily Xenocyprinae. These findings confirm the taxonomic placement of Opsariichthys and provide essential genetic resources for the evolutionary biology, taxonomy, and conservation of freshwater fishes in the Huanghe-Huaihe River Basin.