What it Takes to be a Beluga




Reproduction and Life



Facts and About Me


































ŠLisa Walter, 2007

Delphinapterus Dinner

     The Beluga belongs to the Family Monodontidae, which classifies them as "toothed whales". Yet, they only have teeth to catch the prey not to actually chew it. The beluga does not have a sense of smell to catch prey, so it relies on it's good eyesight and excellent hearing. It is thought that they use their nasal sacs by their blowholes to make noises and use echolocation. Even though they have good eyesight and hearing, they do not use their good senses but instead most of the beluga's diet is composed of bottom feeding and eating sea bed creatures. When bottom feeding the beluga will dive down for about 25 minutes and siphon through the sediment and actually just inhale the food without chewing. They mainly forage for invertebrates in the sand but also do have a taste for halibut, cod, squid and other fish. 

How Do Belugas "Work"?

     Digestive System/ Thermoregulation
   The Beluga whale transports its food through it's digestive system like most other mammals but because they are large animals their metabolism is much slower than most. They consume up to 5% (50-75 lbs) of their body weight everyday and blubber accounts for 40% of their body weight. Because they are slow moving animals only some of the food is used for energy. Most of their food intake is turned into fatty blubber and the blubber is insulation for the whale.

     Circulatory System
    Belugas have a circulatory system, again, like most other mammals. Blood circulates throughout the body, but with a very limited amount of blood circulation through the pectoral fins and the tail. Yet, unlike most mammals, the arteries in the flippers and flukes (tail) are surrounded by veins. This layout creates a system that instead of the heat leaving the arteries and out into the environment, the heat is transferred back to the veins and brought back into the body . The system described is a countercurrent heat exchange and is effective in minimizing heat loss in the cold Arctic Waters.
    Another way that belugas conserve heat is by shunting (limiting blood flow) to the skin while diving to the ocean floor. By shunting blood away from the skin it keeps the heat inside their body and limits the loss of heat as well.

     Respiratory System
When the Beluga shunts blood away  from it's skin it also contributes to maximizing the amount of air that the Beluga needs while diving. From shunting the blood away from the skin it provides more oxygen to the heart, lungs and brain where it is needed. Belugas are not considered deep diving whales but are fully able to make dives deeper than 2,000 feet but on average only dive for about 5 minutes at a depth of 20 ft. Belugas have the oxygen binding protein myoglobin which stores oxygen and provides the whale with a higher oxygen percentage in their blood. The myoglobin also helps the blood contain more oxygen to help prevent oxygen deficiency to the muscles while diving. Also, during dives, the Beluga's heart rate slows (typical of whales) during diving, it can slow from 100 down to 20 beats per minute, this allows maximum oxygen use.


Picture Permission By:  Hejda, E. 2006. The Animal Diversity Web (online).