Sharks can be found in every ocean of the world. To many people, there’s only one kind of shark: the man-eating white shark of the movie Jaws. They think sharks are ruthless predators that attack anything they come across.
Sharks are sometimes thought of as primitive creatures as they have been in existence for million of years. In fact, sharks are very intelligent. They have a fantastic sense of smell and hearing as well as good vision in low light conditions.
Their sense of smell is so acute that they can detect a drop of blood dissolved in over one million gallons of water! And they can hear can detect a struggling fish over two kilometres away.
Sharks do not have external ears. They detect sound with the help of their lateral line system which consists of hundreds of pores along the side of the shark’s body. These pores are highly sensitive to wave movements, pressure changes and vibrations in the water.
There are approximately 350 species of sharks. All sharks are boneless fishes and their skeleton is made of cartilage or elastic tissue. Sharkskin has the same feel as sandpaper and can easily peel human skin off if rubbed against.
Sharks have rows of triangular razor-sharp teeth that get renewed throughout their lives. As one tooth breaks off or wears out, another one rotates forward from the inside of the jaw to replace it.
Predatory carnivores, sharks are rarely man-eaters. Except under unusual circumstances, sharks do not attack people. Most shark attacks are caused by humans getting too close to sharks, or if the shark is provoked and feels threatened.
Only four species are considered dangerous: the great white, tiger shark, bull shark and the oceanic white-tip shark.
They come in all shapes and sizes. While the great white may reach 21 feet in length and weigh over 2,500 pounds, the largest, of course, is the whale shark at 60 feet. The smallest is the spined pygmy at 10 inches. Almost all the species have asymmetrical tails – the upper part is larger than the lower half.
Some sharks lay egg-filled cases, while others give birth to live young ones. The gestation period varies with the species ranging from nine months to 20 months. Again, depending on the species, a female shark can produce two to 135 young at a single time.
Sharks are the most misunderstood creatures in the world. They have an extremely useful role to play undersea. High up in the food chain, they help maintain the balance of the ecosystem by keeping it going.
Unfortunately, sharks are commercially hunted. They are hunted for their oily livers, skin, teeth, flesh, or just killed because they are thought dangerous. This has not only endangered its life but has put the ocean food chain at risk.
It is especially important for us humans to understand the nature of the problem. As social beings, we rule the planet and use its land, water and air resources pretty much as we please, with no thought for tomorrow.
But, as biological beings, we are not the most important link in the food chain. We are a part of the huge food chain consisting of millions of creatures, ranging from the unseen microscopic ones to the big beasts.
And any decision that we may take as the rulers of the planet may ultimately, boomerang on us.
If the shark could speak, that is the message it would perhaps give us.