Perhaps the largest animal to have ever lived, the blue whale can grow to be 100 ft (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. What is the blue whale’s only natural predator? Discuss
Source: The Free Dictionary