The complete mitochondrial genome of <i>Leuciscus chuanchicus</i> (Kessler, 1876) (Cypriniformes: Cyprinidae)

<i>Leuciscus chuanchicus</i>, a fish distributed in the upstream regions of the Yellow River, was the focus of this study, which aimed to depict the structural characteristics of its mitochondrial genome and clarify its phylogenetic relationship within <i>Leuciscus</i>. High-throughput sequencing technology was used to obtain the complete mitochondrial genome of <i>L. chuanchicus</i>. Additionally, a phylogenetic tree of <i>L. chuanchicus</i> and seven other <i>Leuciscus</i> species was constructed based on the mitochondrial genome using the maximum-likelihood (ML) method. The results revealed that the <i>L. chuanchicus</i> mitochondrial genome spans 16,602 bp and contains 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and a non-coding D-loop region. The mitochondrial genome exhibited the highest A + T content (53.7%). ATG was the most common start codon in the protein-coding genes, except for the <i>COX1</i> gene, which started with GTG. The phylogenetic tree constructed using the ML method showed that <i>L. chuanchicus</i> was closely related to <i>L. waleckii walechii.</i> This study adds valuable data on the <i>L. chuanchicus</i> mitochondrial genome, aiding in the understanding of the phylogenetic relationships within <i>Leuciscus</i>. By constructing phylogenetic trees, the evolutionary relationships of <i>L. chuanchicus</i> within <i>Leuciscus</i> were discussed, providing essential data for revising the classification of this genus. Therefore, it also offers a theoretical basis and essential information for biodiversity conservation and germplasm resource assessment of <i>L. chuanchicus</i>.