Dolphin: Mamals with fins

    the name dolphin is originally from ancient greek, delphys which means womb. So, the name dolphin means " a fish wiht womb." Most dolphin are gray, but some species have black stripes, spots or black part. Dolphins have a streamlined body which has undergone several important and impressive adaptons to swim efficiently in the ocean. That's why they are hairless, unlike mammals, because hairs are inconvenient for swimming. Male dolphin are called "bull," females are "cows," and young dolphins are called "calves."
  
    there are 32 species of ocean dolphins and 5 species of river dolphins. The smallest species is the Maui dolphin which can grow to a
round 1.2 m in length and 40 kg in weight. The largest dolphin species is the orca, or famously known as killer whale. Male orcas grow to about 9 metrs and weight up to 6 tons. The most popular dolphin is the bottlenose dolphin. It can grow up to 2.8 meters and 300 kilograms.
  
    Dolphin live in a group which is called a "school" or a "pod." There can be up to a dozen dolphins in a pod. In places with an abundant supply of food, several pods can merge temporarirly,forming a superpod, a group of more than 1.000 dolphins.Dolphins communicate using a varietyof clicks, whistles and other vocalizations. They make ultrasonic sounds for echolocation. This technique uses the same principles of radar, and is used to find food navigate.
  
    Dolphins are highly sociable animals. They can establish strong social bonds. Dolphins will stay with injured or ill individuals. They even help the sick ones to breathe by bringing them to the surface if needed. If another dolphin is drowning. other dolphins will support it with their bodies so that its blowhole is above the water allowing it to breathe. They have also been seen protecting swimmers from sharks by swimming in circles around the swimming or charging the sharj to make them go away.
  
    Most dolphins live long lives. The bottlenose dolphin can live over 40 year and the orca can live to be 70 or 80 years. They are found worldide. mostly in shallow seas of the continental shelves. They consume a variety of prey including fish. squid and crustaceans. They often hunt together by surronding a school of fish, trapping them ang taking turns swimming through the school and catching the fish. Dolphins will also follow seabird, other whales and fishing boats to feed opportunistically on the fish the scare off or discard.
  
    They are well known for their agility and playful behavior,making the a favorite of wildlife watchers. Many species will leap out of the water , spy-hop (rise vertically out of the water to view their surrounding) and follow ships, often synchronizing their movements with one another. Scientists believes that dolphins conserve energy by swimming alongside ship. Dolphins are able to dive to great depths, and also leap to great heights. They may leap to avoid predators or show how powerful they are to females at mating time. Noisy splashing jumps may also be used to herd fish. Bottlenose dolphins can dive to depths of over 500m. They can satay up to 15 minutes underwater. Aren't they amazing ?

Courtesy : C n S English Teen Magazine