The blue whale is the biggest living animal in the world. It grows up to 30 meters long and the largest can weigh more than 180 metric tons. weigh as much as an elephant and its heart can be the size of a small car. Ababy blue whale weighs up to 2.7 metric tons when it is born and gains 91 kilograms every day for its first year. But these enormous animals can swim at a fast speed of 32 kilometers an hour.
During certain times of the year an adult whale eats about 3.6 metric tons of krill a day. The whale swims slowly through the water with its mouth open and thousands of tiny fish and plankton swim into it. Bu