Which of these mammals is the biggest?

Of all the whale species in our oceans, the largest and heaviest are blue whales. In fact, they are the largest animal on the planet. These serene, captivating animals can reach lengths of up to 98 feet and weigh up to 199 tonnes. Their heart is the size of a small car and weighs 1,500 pounds. These majestic animals are found in every ocean but are more common in the Southern Hemisphere.

Source: Wild Life Trip