Beluga whales, with their distinctive white coloration, often spark curiosity about their place in the marine mammal family. People often wonder if these Arctic inhabitants are a type of dolphin or a different kind of whale. While they share characteristics with both, their scientific classification clarifies their unique standing.
The Cetacean Family Tree
Marine mammals like whales, dolphins, and porpoises all belong to the order Cetacea, a diverse group adapted to aquatic life. Within Cetacea, there are two primary suborders: Mysticeti, known as baleen whales, and Odontoceti, or toothed whales. Baleen whales, such as humpbacks and blue whales, filter feed using baleen plates.
Toothed whales possess teeth and utilize echolocation to navigate and hunt prey. This suborder includes a wide array of species, from sperm whales to dolphins and porpoises. Dolphins themselves are a specific family, Delphinidae, found within the Odontoceti suborder.
Belugas: Toothed Whales, Not Dolphins
Belugas are toothed whales, placing them within the Odontoceti suborder, but they do not belong to the Delphinidae family. Beluga whales are classified under the family Monodontidae, a group they share exclusively with the narwhal. This means that while all dolphins are toothed whales, not all toothed whales, including belugas, are dolphins.
The scientific name for the beluga, Delphinapterus leucas, translates to “white dolphin without a fin,” which can contribute to common confusion. Their classification within Monodontidae reflects distinct evolutionary pathways and anatomical differences that set them apart from “true” dolphins. Both belugas and dolphins are intelligent and social, yet their family separation is well-established.
Unique Beluga Characteristics
Beluga whales possess several unique traits. Their most recognizable feature is their pure white skin as adults, which provides camouflage in their icy Arctic and sub-Arctic habitats. Calves are born dark gray and gradually lighten over several years.
Belugas have unfused neck vertebrae, allowing them to turn their heads from side to side and nod. This flexibility aids their maneuverability in shallow, ice-filled waters. They also lack a dorsal fin, an adaptation for navigating under ice sheets and reducing heat loss, having a tough dorsal ridge instead.
Belugas are renowned for their extensive vocalizations, earning them the nickname “sea canaries.” They produce a wide range of chirps, clicks, whistles, and squeals for communication, echolocation, and maintaining group cohesion. Their bulbous forehead, called a melon, is flexible and changes shape as they produce sounds, assisting in focusing acoustic signals.