Desmophyllum pertusum (formerly Lophelia pertusa) is the dominant cold-water reef-building coral globally, forming vast three-dimensional biogenic reef structures at depths of 200–1000 m in cold, aphotic waters worldwide that support remarkable biodiversity with hundreds of associated species documented per reef. The species is long-lived and extremely slow-growing, with reefs taking centuries to millennia to develop and being highly vulnerable to bottom trawling, oil and gas development, and ocean acidification. Conservation of cold-water coral reefs is a major focus of deep-sea management globally. Genomic data have been generated for this species and are available in public databases, enabling comparative studies of cnidarian evolution and ecology.