Blue Whale: Nature’s living museum of wonders Nature gifted certain special and rare qualities to the blue whale but the boons themselves have
D N Kaushik
become banes for the whales. Reason – they were equally useful for the human beings as well. Results – blue whales too now are on the verge of extinction
A recent statistics reveals a startling fact that merely 4,500 blue whales exist in various oceans of the world. According to the 1938 census, nearly 1,00,000 blue whales existed in various oceans. Their constant hunting and illegal killing with spears reduced their number t o just 12 ,000 by 1953 and according to the 2010 census they are just 4500 in number. The reason for the decline in the population of blue whales is their brutal hunting being done by the fishermen of countries like Russia, Japan, Norway, Denmark , Holland, etc. If this savagery towar ds the blue whales con tinues unchecked, the time is not far when not a single blue whale would exist on our planet. The future generation, would acquaint themselves of this gigantic creature; just like the dinosaurs, through pictures and documentary films. The International Union for Conservation of Nature/IUCN has put the blue whales on the endangered species list, and the activists of IUCN are trying hard to pr otect this gigantic creatur e from extinction. The International Whaling Commission has implemented various laws against blue whale hunting, still illegal The pathetic condition of the whale after being hunted by a Japanese whaler. Seems like it was not a living creature but a bundle of goods
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hunting continues to satisfy the human greed. Considering the huge difference between the number of 1,00,000 blue whales in 1938 and just 4,500 in 2010, it becomes evident that mankind has surpassed all the
Blue whale l ev e l s of cruelty, and is savagely pushing this creature which was evolved by nature in millions of years; towards extinction. The blue whale, however, is not an ordinary creature but is like a natural museum of wonders. Due to its various unique features and qualities it holds many world records of which the popularly known fact is only that it is the world’s largest animal. An adult blue whale measures 18 to 21 metres (70 to 80 feet) long. (FYI: The world record has been set with a length of 32.3 metres). Its immensity can be well understood by illustrating a comparative study of a whale whose weight is equivalent to 12 elephants or 35 cows or 1,700 human beings! Surprisingly, the world record for the heaviest whale is set by a huge gigantic blue whale weighing 209 tonnes which was caught on March 20, 1947. Its weight was equivalent to eight dinosaurs known as Brontosaurus put together. Considering its huge size, a question definitely comes to mind that what made blue whale evolve as such a giant mammal? Billions of years ago, the predecessors of the blue whale were terrestrial. They were a little smaller than the dinosaurs, yet they were heavily built. To reduce the impact of their body weight on the movement, they slowly drifted towards the ocean during the long period of evolution. They began spending most of the day time in water and with the passage of time and progression of evolution; their short legs took the form of flippers and a fin on the tail developed to help them swim. The form of their body also changed from that of a dinosaur to an aerodynamic shape like a fish, which would enable them to move in the waters without much resistance. The biggest change was in their height and weight. The density of water is 800 times more than the density of air due to which this gigantic aquatic creature does not feel its body weight much. Water itself helps it to stay buoyant. As such, the huge oceans would not provide any hindrance in its motion due to which they can afford growing in size and yet swim fr eely. Though we have mentioned the av e rage weight of the blue whale, yet there are no weighing scales which can actual ly
measure its accurate weight. However, upon asking the sailors of the whaler ships who ruthlessly kill whales, it becomes evident that they can be weighed only after being cut into some pieces and each body part weighed individually. Though cutting up the blue whale into pieces is a repulsive thought, yet; let us analyse the anatomy of a blue whale. The body of this aquatic mammal has 26 tonnes fat and 56 tonnes flesh. The vertebral bones weigh 10 tonnes, the jaw bones weigh 2 tonnes while the skull weighs 4.5 tonnes! The liver weighs 1 tonne and the tongue, 3 tonnes. The biggest wonder of the blue whale’s body is its heart, that weighs about 500 kilograms, and measures 1.5 times bigger than a small car like Maruti Frontie. (FYI: The blue whale holds the record of having the largest heart among all animals). The extremely powerful pump-like heart circulates 8 tonnes of blood through the veins in the entire body. Surprisingly, the main artery is big enough in diameter for a small child to swim across. The above description regarding the physical attributes pertains only to the blue whale. There are other genus of whales too, which can broadly be divided into two categories viz. the whales that have teeth, and whales without teeth. For instance, the killer whale found in almost all the oceans of the world has 40 to 48 sharp teeth, which enable it to tear its prey apart. The sperm whale too has a set of maximum 54 sharp teeth, while the humpback and finback species do not have teeth at all. In short , there are fiv e specie s of whales that have Pakicetus: The teeth, while nine earliest known kinds of them do ancestors of the not have teeth. whales How does the Safari July, 2011 29
Blue whale
Crustaceans known as krills are the blue whale’s main diet
The blue whale has such comb-like structure in its mouth
blue whale hunt and eat its food in the ocean without the teeth? Moreover, considering the size of the whale, one can imagine the amount of food required by it, to satisfy its hunger. Compared to an average human being who requires 2400 calories on a daily basis, the daily requirement of the whale is 2,40,00,000 calories! It can satiate its hunger only after devouring nearly 4,100 kilogr ams of f ood daily. Without the teeth, it becomes difficult to chew the food, but in case of blue whale, Nature has already taken this into consideration and has solved the problem. Instead of teeth, Nature has given a comb-like structure known as baleen in the whale’s upper jaw only. It gives an illusion of a shutter hanging from the upper jaw but a closer look reveals the 1.25 centimetre gap between the two ‘t ee th’. This gap enables it to strain out the seawater that enters its mouth along with the food. Here’s how it works. The whale feeds on krill – a shrimp-like marine crustaceans measuring nearly 2 c en timetr es, found in abundance near Antarctica whose colour gives the ocean water a reddish look. The krills are found in plenty during the springtime, which help the whales have a feast. The blue 30 Safari
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whale with its mouth wide open like a huge cave allows thousands of litres of water, along with krills, to enter inside. Then, it immediately closes its jaws and with the aid of its 1 metre thick tongue pushes the water out of the mouth with a great force. The water gushes out from the mouth through the gaps between the so called ‘teeth’ but the krills, due to their size, cannot escape with the water. Thousands of krills eventually settle on the blue whale’s tongue—and are finally pushed into the warehouse-like giant stomach of the whale. The blue whale consumes nearly 50 to 75