Hidden in the depths, discovery of a new spiny sucker eel of the genus Lipogenys Goode and Bean 1895 (Teleostei, Notacanthiformes, Notacanthidae) in the eastern North Atlantic Ocean.

This study describes Lipogenys hyalinumvelum, a new species of the genus Lipogenys found on the Portuguese coast on the northeastern Atlantic during a crustacean survey. Information on the classification history and known distribution of the genus Lipogenys is provided. Dichotomous keys to the genera of Notacanthidae and the species of Lipogenys, based on morphology, are provided. The specimens were analysed using both morphological and molecular methods, including DNA sequencing of the COI and 16S genes. The distinct genetic characteristics support the recognition of the present specimens as a new species. The hyaline color of the flap at the posterior edge of the operculum is a characteristic that differentiates L. hyalinumvelum from Lipogenys gillii and provides the etymology of the species name.