How Beluga Whales have Adapted to their Environment
By zteve t evans
Beluga whales inhabit the extreme environment of Arctic and sub-Arctic waters and over time have evolved a number of body adaptations to help them cope in such a cold and unwelcoming place.
Skin
Camouflage of the Beluga
Beluga whales are one of the most distinctive species of whales.
Adult beluga whales are entirely white or white grey in colour which makes them relatively easy to identify. When calves are born they are usually grey, but in the first month of their lives their colouring turns to blue-grey or dark grey. Gradually as they get older they lose this colouring with their skin turning completely white by the age of 9 years old in males and 7 years old in females.
The white colouration is an adaptation to the skin that belugas have evolved which increases their chances of survival by camouflaging them in the polar ice caps against predators such as orca whales and polar bears.
Uniquely belugas are the only cetaceans that shed their skin. The epidermis becomes thicker and the skin turns yellowish along the back and on the fins. During the summer months when they migrate to estuaries they rub their backs on gravel on sea or river beds scraping off the cutaneous layer.
Beluga whales are one of the most distinctive species of whales.
Adult beluga whales are entirely white or white grey in colour which makes them relatively easy to identify. When calves are born they are usually grey, but in the first month of their lives their colouring turns to blue-grey or dark grey. Gradually as they get older they lose this colouring with their skin turning completely white by the age of 9 years old in males and 7 years old in females.
The white colouration is an adaptation to the skin that belugas have evolved which increases their chances of survival by camouflaging them in the polar ice caps against predators such as orca whales and polar bears.
Uniquely belugas are the only cetaceans that shed their skin. The epidermis becomes thicker and the skin turns yellowish along the back and on the fins. During the summer months when they migrate to estuaries they rub their backs on gravel on sea or river beds scraping off the cutaneous layer.
Beluga Whale Physique
Male belugas can grownup to 25% long than females and tend to be stronger in body. When fully grown, males can be 11-18 feet long and can weigh between 2,400-3,500 pounds, though some have been known to reach 4,200 pounds. Females grow to 9.8-13.5 feet in length and usually weigh 1,500-2,600 pounds. Males and females achieve their maximum size by the time they reach 10 years old. Among the toothed whales they are regarded as a mid-size species.
Their bodies have evolved to help them cope with the extreme cold of the Arctic waters. They have a stout cone shaped body with the tail as the point. Belugas have a higher percentage of body fat compared to those that do not live in the Arctic or sub-Arctic whose fat composes about 30% of body weight. In comparison fat comprises of 40-50% of the beluga’s body weight. Apart from the head all of the body has a layer of fat up to 5.9 inches thick which insulates it from the cold waters where temperatures can be as low as between 0-18 degrees Centigrade. It also functions as a crucial reserve of food.
Male belugas can grownup to 25% long than females and tend to be stronger in body. When fully grown, males can be 11-18 feet long and can weigh between 2,400-3,500 pounds, though some have been known to reach 4,200 pounds. Females grow to 9.8-13.5 feet in length and usually weigh 1,500-2,600 pounds. Males and females achieve their maximum size by the time they reach 10 years old. Among the toothed whales they are regarded as a mid-size species.
Their bodies have evolved to help them cope with the extreme cold of the Arctic waters. They have a stout cone shaped body with the tail as the point. Belugas have a higher percentage of body fat compared to those that do not live in the Arctic or sub-Arctic whose fat composes about 30% of body weight. In comparison fat comprises of 40-50% of the beluga’s body weight. Apart from the head all of the body has a layer of fat up to 5.9 inches thick which insulates it from the cold waters where temperatures can be as low as between 0-18 degrees Centigrade. It also functions as a crucial reserve of food.
Head Shape of the Beluga
Beluga whales have a distinctive head shape. Most species of toothed whales have a special organ called a melon that they use for echolocation. This is found on the centre of the forehead which gives it head a distinctive bulbous appearance unlike that of any other cetacean. The melon is malleable and changes shape when the beluga makes sound emissions. The beluga does this by blowing air around its sinuses while making sounds.
The Neck of the Beluga Whale
Many species of cetaceans have evolved so that the vertebrae in their neck are fused together and consequently they cannot turn their heads. Beluga whales have evolved so that these vertebrae are not fused together which gives them the ability to turn their heads laterally without the need to rotate its body. This gives the head extra manoeuvrability which helps them with detecting prey, seeing predators early and with movement in the depths of the seas.
Absence of a Dorsal Fin
Belugas do not have a dorsal fin but they have evolved a dorsal ridge that begins around the midpoint of the back and continues to the tail flukes. This ridge may be notched like a series of bumps and may be dark grey in colour. The absence of the dorsal fin makes it easier for them to manoeuvre under the ice sheet and it also reduces their surface area so they loose less heat in the cold seas.
Still Making Discoveries About Belugas
Over the centuries belugas evolved these adaptations that distinguish them from other whales and gives and helps them to survive in the cold waters of the Arctic and sub-Arctic seas it inhabits. Scientists are still making discoveries about how they live and survive in such an extreme environment.
© 18/06/2014 zteve t evans
Beluga whales have a distinctive head shape. Most species of toothed whales have a special organ called a melon that they use for echolocation. This is found on the centre of the forehead which gives it head a distinctive bulbous appearance unlike that of any other cetacean. The melon is malleable and changes shape when the beluga makes sound emissions. The beluga does this by blowing air around its sinuses while making sounds.
The Neck of the Beluga Whale
Many species of cetaceans have evolved so that the vertebrae in their neck are fused together and consequently they cannot turn their heads. Beluga whales have evolved so that these vertebrae are not fused together which gives them the ability to turn their heads laterally without the need to rotate its body. This gives the head extra manoeuvrability which helps them with detecting prey, seeing predators early and with movement in the depths of the seas.
Absence of a Dorsal Fin
Belugas do not have a dorsal fin but they have evolved a dorsal ridge that begins around the midpoint of the back and continues to the tail flukes. This ridge may be notched like a series of bumps and may be dark grey in colour. The absence of the dorsal fin makes it easier for them to manoeuvre under the ice sheet and it also reduces their surface area so they loose less heat in the cold seas.
Still Making Discoveries About Belugas
Over the centuries belugas evolved these adaptations that distinguish them from other whales and gives and helps them to survive in the cold waters of the Arctic and sub-Arctic seas it inhabits. Scientists are still making discoveries about how they live and survive in such an extreme environment.
© 18/06/2014 zteve t evans
References and Attributions
Copyright zteve t evans 18 June 2014
Copyright zteve t evans 18 June 2014
- File:Delphinapterus leucas 2.jpg From Wikipedia - Beluga (Delphinapterus leucas) - Author: Steve Snodgrass - Creative Commons Attribution 2.0 Generic license.
- Beluga whale - Wikipedia, the free encyclopedia
- Basic Facts About Beluga Whales - Defenders of WildlifeBeluga whale
- Beluga Whale - NOAA Fisheries