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Blue whales are still very much a mystery for biologists around the world. Currently the largest creatures on Earth, these sea mammals are packed with an immense appetite, but scientists have only few theories on how they obtain their food.
But more is about to be revealed about their dietary habits as scientists have been using tags for monitoring the movements of blue whales swimming in the waters near California’s coast. The study found their favorite food is the krill – a small shrimp-like crustacean – debunking the previously hold conception that blue whales are undiscriminating grazers.
Scientists were surprised to see how the giant marine creatures adapt their food intake depending on how flourishing the population of krill is. Feeding frenzies ensued each time the krill were in high numbers, but some sort of food restrictions could be noticed when less krill swam in the area.
Research ecologist Elliott Hazen of the U.S. National Oceanic and Atmospheric Administration Fisheries’ Southwest Fisheries Science Center and the University of California Santa Cruz, has an explanation for this phenomenon. It turns out blue whales are terrific strategists and that all boils down to oxygen conservation.
When prey quality is high, the sea mammals discard all consideration for conserving oxygen and go in for deep foraging, unlike the times when when prey quality is low. The feeding technique is also fascinating, seeing that blue whales are actually filter-feeders.
Using their keratin-based baleen plates, the giant mammal has an efficient way of feeding while also cleaning the ocean’s water. The whale speeds up, opens its wide mouth, and then gulps down water filled with krill up to 130 percent of its weight.
Using its tongue and throat muscles, it then pushes water out of its mouth, retaining only the krill. Each day, the number if krill consumed rises to about four tons, which sounds like a lot. But if we consider that the average adult whale weighs about 180 tons and measures up to 98 feet (30 meters), the food intake is a little more justified.
Due to the extreme whaling that took place in the 20th century, blue whales are on the endangered list, still recovering after almost being wiped to extinction. Even though they are now present in all the Earth’s oceans, the 10,000 blue whales are still in need of protection.
Image Source: Resimsi
