Perhaps the largest animal to have ever lived, the blue whale can grow to be 30.5 m long and weigh as much as 200 tons. It eats as much as 4 tons of krill a day, and its massive mouth can hold up to 100 tons of food and water, but its throat restricts the passage of anything wider than a beach ball. Once abundant, it was nearly hunted to extinction before being placed under the protection of the international community in 1966.
Question: What is the blue whale’s only natural predator?
