The blue whale is the biggest animal that has ever lived on earth. They can reach up to 100 feet in length and weigh up to 150 tons, which is about the weight of 30 elephants. The blue whale's heart is about the size of a small car beats about 5-6 times per minute on the surface and drops to 3 beats per minute when it dives to control its metabolism. Source
Blue Whales
Blue Whale Interesting Facts
