Dolphins - the 'semi humans' at sea

By Amal HEWAVISSENTI

The dolphins' incredible capacity to learn and perform an astonishing number of tricks has made them popular stars in movies, television as well as marine showplaces. Their ability to be trained easily and to display various complex behaviours have made them well-liked attractions at many ocean aquariums throughout the world. Dolphins which are the most playful and intelligent group of animals living in the sea, have been well noted since ancient times for their frolic some habits around human divers and boats. Certain members of major dolphin family dwell in rivers or lakes but most dolphins inhabit deep oceans, while others are typically found in coastal waters, along beaches, in bays and harbours. There are several different species of dolphins in the world but the best known of all is the bottle nose of the Atlantic Ocean. This type of dolphin is more often seen in massive sea aquariums because it lives well in captivity and has been closely surveyed by scientists, more than any other small whale.

The dolphin is usually grey on its back and sides shading to white towards the belly. Its back fin resembles that of a shark and the two flippers also remind one of those of a shark. Strangely enough within each flipper there is a bone formation very much similar to that of a human arm and the skeleton of the flipper even includes five fingers."Common dolphins are 8 to 9 feet long on maximal growth and are often sighted gambolling around ships and swimming with schools of smaller fish.The Killer whale, the largest member of dolphin family, earned its name because it preys on seals, sea lions, small dolphins, fish as well as squid which are its preliminary diet. On the other hand, killer whale is not a ferocious killer that attacks humans, quite contrary to the legendary accounts of sailors being swollen alive by killer whales at the distant sea.

In contrast to fish that can breathe underwater, the dolphins have to come to the surface of the water to breathe and dolphins have acquired the natural skill to get a breath of air quickly and efficiently while swimming at full speep.

The baby dolphin is typically born tail first in to the world of water after the mother dolphin carries her baby for approximately a year. With mother's succour, the baby swims immediately to the surface for its primary breath of air.

The most prominent trait of dolphins is that unlike most mammals sleeping at one time, they take momentary naps during both day and night. Though we may believe that dolphins see well under water but poorly in the air, this strange aquatic animal has surprisingly good vision out of the water. These animals are revealed to make a variety of sounds such as barks, yelps, yaps and even mewing sounds to convey their different moods and to locate food. The latest scientific findings have substantiated dolphin's active use of sonar to gather information about its environment. (Sonar? - Sounad Navigation Ranging)Even if dolphins are as free living and untamed as deer or tiger, they voluntarily associate with humans unlike most wild animals. Every person at sea is well aware of how dolphins accompany boats and ships merely for human company and sport but no dolphin has ever shown any sign of interest in food from man.

It is appealing to observe that dolphins are known to aid their own kind by holding an injured animal at the surface of water between two of dolphin companions until they reach a safer place.Dolphins have been proved to be the quintessence of playful and intelligent animals ever to devil on earth and they make themselves unique among wild animals by seeking out swimmers and boaters, apparently just for human companionship.

Sometimes, when a swell is rolling towards the shore, they are seen riding the waves and when the water becomes shallow, they dive out of the wave and swim towards the sea to catch another.

For a "game of catch", a small rubber tube can be tossed to someone standing by the tank and when tossed back, it may be caught on a dolphin's snout to "make a ringer". This is one of the games the dolphins taught people to play with them. Sometimes the dolphin had to demonstrate the tossing of the ring repeatedly before the human player learned to throw it back, instead of dropping it in the water for the dolphin to fetch. Such creative play is a clear signal of intelligence.

Moreover, dolphins exhibit a singular talent to recognize themselves in a mirror and this self recognition, another sign of intelligence, is a character previously seen only in humans and the great apes.The single and most serious threat to world's dolphin population is posed by tuna fishing since schools of tuna frequently swim underneath schools of dolphins and fishing nets are laid around them both.

Hundreds of thousands of dolphins have been killed when the nets are pulled in. since dolphins too are captured along with the tuna and they drown.