Delectopecten is a small genus of the family Pectinidae (Bivalvia: Pectinida) that remains poorly studied in terms of both morphology and phylogeny. Here, we describe the first member of this genus from deep-sea hydrothermal vent ecosystems, D. thermus sp. nov., based on morphological investigations and molecular analyses of a specimen collected from the Higashi–Ensei vent field (962-m depth) in the northern Okinawa Trough. Morphologically, this new species resembles D. vancouverensis and D...