The Blue Whale Blue whales are considered to be the largest animals that have ever existed on Earth. They are part of the baleen whales category and the rorquals family, along with the humpback whale, the minke whale, the fin whale and the Bryde's whale. A blue whale can reach almost 30 meters in length and it can have a weight of more than 200 tons. A blue whale baby can drink up to 590 liters of milk and it can add up to 90 kg to its weight daily. This might be shocking but the heart of a blue whale has the size of a car and its arteries are so big that a child could sit on them. A medium blue whale can weight 160 tons which is the equivalent of 30 elephants or 160 people that weight 90 kg each. But despite their huge dimensions, the eyes of a blue whale are just the size of a cup of tea, and their external ear is just as big as the tip of a pencil. Adult blue whales eat a lot of food, and their mouths can keep 45,999 liters of water, the equivalent of 256,000 glasses. But blue whales don't swallow all this water, they use their baleen plates to filter it and extract  krill and copepods which are their main menu. Blue whales can reach speeds of 35km per hour. Blue whales have been victims of excessive hunting over the years and they were on the verge of extinction, although they were not very easy to kill. Blue whales can be found in all oceans. The largest populations of blue whales can be found in the Southern hemisphere, in the North Pacific and the North Atlantic Ocean. Sexual maturity lasts from 5 to 10 years and a female can give birth to a baby blue whale every two or three years, babies  are born in warm waters during winter days. Pregnancy lasts from 10 to 12 months. i think we should protect whales so go here for more info www.defenders.org/blue-whale-adopt