whales and dolphins are members of the scientific order Cetacean. They are warm blooded and bear their young alive and the babies nurse their mother’s milk. They live entirely in water but must breath air through their lungs. They have fish like bodies with a thick layer of fat or blubber to keep them warm. They also have flippers for front limbs, but do not have hindi limbs. Unlike most other mammals, they have very little body hair. Seventy-five species of whales, dolphins and porpoises in the ocean all belong to the order Cetacea. They are the only mammals, other than manatees, that live their entire lives in the water. Some whales are huge. The blue whale, for example, grow to 100 feet in length and over 200 tons in weight. It is the largest animal that has ever lived on earth. Some whales, such as the Dolphins, grow only three feet long. Like other mammals, such as cats, dogs, deer, mice and humans, whales are warm-blooded. Whales breathe air and nurse their young. Whales may also be the most intelligent animals in the ocean. Some whales, such as the bottlenose dolphin, sperm whale and killer whale, have teeth for grabbing and holding their food. Other whales, such as the right whale and the blue whale, do not have teeth. These Whales have rows of baleen in their mouths for catching food. Baleen has many bristles like a broom used to trap small animals in the whale’s mouth. Baleen whales eat mostly shrimp like animals called krill, copepods and small fish. Toothed whales catch larger prey including fish, squid and octopus. Killer whales even eat other large mammals such as seals and Sea Lions.
WhalesWhales are amongst the most enigmatic and fascinating of all creatures. The Blue Whale is the largest animal ever to have lived on earth, at up to 100 tons, easily out-weighing the heaviest dinosaurs, even an “ordinary” sized whale is a vast and impressive creature. Whales are huge, but elusive and difficult to see which adds to their mystery and fascination. They are highly intelligent animals with an elaborate social life, no possessions and the complete freedom of movement in three dimensions. Whales are mammals as are humans, dogs, cats, elephants and anguantibos amongst others. This means that they are not fish. They breathe air and so must return to the surface at regular intervals to get a breath. They give birth to live young that stay with the mother for over a year and feed on milk produced by the mother.
Dolphins are marine mammals that are closely related to whales and porpoises. There are almost forty species of dolphin in seventeen genera. They vary in size from 1.2 m and 40 kg, up to 9.5 m and 10 tonnes. They are found worldwide, mostly in the shallower seas of the continental shelves, and are carnivores, mostly eating fish and squid. Their family is the largest in the Cetacean order, dolphins evolved about ten million years ago, during the Miocene. Dolphins are among the most intelligent animals and their often friendly appearance and seemingly playful attitude have made them popular in human culture.
Facts about Whales and Dolphins
Whales and dolphins appeared 50 million years ago.
There are 15 species of baleen whales and 74 toothed whales (42 are dolphins).
The largest whale is the blue whale up to 33 m in length and 181 tons.
Blue whale is solitary or lives in small groups of 2-3 individuals.
The large size of the whale is due to the food abundance in the sea and it is also a method of fighting the cold water of the sea.
The heart of a medium sized baleen whale weighs 700 kg, the tongue about 3 tons, the fatty liver one ton and the 3 m long stomach around 500 kg (1250 ponds), requiring 1200 kg to be filled!
Blue whale’s brain weighs 5 kg while that of the sperm whale 7 kg, representing the largest brain in nature.
Whales have minute eyes: those of a blue whale’s are no larger than a small plate.
The whale’s lungs can store at each inspiration 5000 liters of air. They usually breathe at every 15 minutes but they can hold their breath up to over an hour in the case of the sperm whale.