Lissodelphis

Right whale dolphins are cetaceans belonging to the genus Lissodelphis. It contains the northern right whale dolphin and the southern right whale dolphin. These cetaceans are predominantly black, white beneath, and some of the few without a dorsal fin or ridge. They are smaller members of the delphinid family, oceanic dolphins, and very slender. Despite scientists being long acquainted with the species, little is known about them in terms of life history and behaviour.