The blue whale is the biggest animal on Earth. Like all other whales, it belongs to the mammals. It can way up to 33 meters in length and can weigh 200 tons. The heart itself already weighs as much as a small car, which is 600 to 1000 kilograms and pumps 100 liters of blood through its body while doing so. Like other whales, the blue whale has to breathe after a couple of minutes. When it breathes it releases a giant spurt of water, like a geyser, that's called blow. The blow can tower up to nine meters in the air.
Blue whales live in all seas. They wander between warmer areas during winter and colder areas during summer. In colder areas, blue whales find a lot of little crabs and plankton. A different word for them is krill. Blue whales eat 3 to 4 tons of them per day and build up large fat reserves. Blue whales need this fat because they don't eat during winter.
It cannot chew its food, because it doesn't have teeth. Instead, he has horn substances called whalebone. They work like a filter, that keeps everything edible in its mouth.
When blue whales search for food, they swim very slowly, like a human going on a walk. When they wander bigger distances they go as fast as a car in a 30mph zone. Male blue whales usually travel alone, and females travel in groups with other females and their kids.
Blue whales get sexually mature after 5 to 6 years. The blue whale mother carries her babies in her belly for up to 11 months. When the babies are born, they are about 7 meters long and they weigh about 2.5 tons. That's about as heavy as a heavy car. The mother feeds the pup for about 7 months. Then it is about 13 meters long.