Abstract
We present novel genetic data for the rare deep-water shark Pseudotriakis microdon , including sequences for COI, 16S rRNA, NADH2, and nuclear ITS2 from specimens sampled in the North Atlantic Ocean. These data, combined with all publicly available sequences, reveal clear genetic structuring: Atlantic and Indian Ocean populations form a cluster clearly separated from West Pacific individuals. The ITS2 marker, previously unreported for this species, appears particularly divergent, reflecting a poorly sampled phylogenetic branch and representing a valuable genomic resource. These findings lay the groundwork for future conservation and taxonomic studies of P. microdon populations.