Whales. There are more then 80 different species of whales. The biggest species are the blue whales. They can reach 30 meters of length and 150 ton. The whale heart has 2 meter of high and 1\2 ton. their tongue has 3 meters. It is heavier than an elephant. Whales are mammals, not fishes. They have a warm blood, they need to go to the water surface to breath and their babies drinks milk from the female whales. They are very intelligent, like having a fun with other whales, and game fishes. They can “sing” under of water to communicate each other.