Beluga whales are the only living member of the genus, Delphinapterus, meaning “dolphin without a fin,” as they have a shallow ridge along the back, instead of a dorsal fin.
Beluga whales are the only living member of the genus Delphinapterus. The name derives from the Greek words delphinos (“dolphin”), a (“without”) and pteron (“fin” or “wing”). Belugas lack a dorsal fin, hence the name “dolphin without a fin.” A dorsal fin would be prone to injury from ice and would be a site for heat loss. Belugas do, however, have a shallow ridge along their back.
However, in spite of what the name suggests, belugas are not dolphins, which is a term reserved for members of the family Delphinidae.
The genus and species Delphinapterus leucas were identified by Pallas in 1776.