Abstract
We report the first confirmed record of the largescale triggerfish, Canthidermis macrolepis (Boulenger, 1888), from the South China Sea, based on a specimen collected near Wenchang, Hainan, China. Sequencing of the complete mitochondrial genome (16,527 bp) revealed typical vertebrate mitogenome organisation, comprising 37 genes and a control region. The genome displayed A + T bias (55.1%) and strong purifying selection across all protein‐coding genes. Phylogenetic analyses with both cytochrome c oxidase subunit I (COI) and whole mitogenome datasets confirmed the monophyly of Canthidermis and its sister relationship with Canthidermis maculata , consistent with previous morphological and molecular studies. However, the COI gene, while distinguishing most balistid genera, failed to separate Balistoides viridescens and Pseudobalistes flavimarginatus —suggesting recent divergence or taxonomic complexity—highlighting the need for integrative taxonomic approaches. This study provides a valuable mitochondrial genomic resource and clarifies the phylogenetic position of C. macrolepis , enhancing the understanding of triggerfish diversity and evolution in the Indo‐West Pacific.