Nutrition
Everything from prey location, prey acquisition and prey sources. A detailed look at the nutrition of Blue Whales
Blue Whale Food Source : Krill
Its some what of a paradox that the largest animal to ever live, gains all its nutrition from a small shrimp like crustacean called krill.
Blue whales are a member of the Mysticeti which are the Baleen Whales. Baleen is one of the adaptations blue whales, and all other baleen whales, have that allow then to eat large amounts of small food source such as krill and other small bait fishes like anchovies.
Baleen is made up of keratin which is the same substance that is found to make human finger nails and hair. In the different species of baleen whales there are different lengths layouts and hardness of these specialized and highly adapted structure.
Measuring on average around 2 inches its hard to believe that such a small organism can be the only food source for the largest animal to ever live. Yet what they lack in size they make up for in sheer numbers.
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Krill are very gregarious and live in large groups numbering as much as 100,000 which is to the benefit of the blue whales, as they need anywhere between four to eight tons of krill in order to survive.
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Learn more about how much energy blue whales spend on a daily basis and why they need so much food click the button below.
Baleen is essentially teeth that have been evolved over millennia to act more like a strainer. The way the blue whales use this adaptation is that when they come across a ball of krill they swim through the krill with their mounts open then close they mouths around the krill and use their to push the water through the baleen and the krill gets caught.
The amount of krill that a blue whale can consume in one day is immense. The total calories for a full day of eating can be upwards of 480 million calories. Which compared to the recommended 2000 for humans, puts into perspective the amount of energy needed just to run their 100 foot 100 ton bodies.
Its estimated that for every dive for food a blue whale expends around 11,400 calories and takes in 2,700,000 calories per dive.
to learn more about blue whale energy expenditure, click the button to the right.
The best way to find blue whales is to find their food source. This can vary during different times of year and even different points in the day. As the krill they are chasing move around quite a bit looking dfor cold nutrient dense waters, but also go through something called a circadian diel vertical migration. Which simply means they change their depth dependent on what time of day it is
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The krill are considered photophobic and during the day when the sun is out stick to deeper darker waters, while during the evening and night they are closer to the surface of the water eating on the different types of plankton.
So naturally the whales tend to do the same thing. They will spend a lot more time during the day in deeper water only coming to the surface to breathe and rest. But when they have caught their breath and are fully rested they can dive upwards of 315 meters deep and up to 30 minuets.
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Blue whales entire day to day activities is taken up with this relentless search for food in order to just keep their massive bodies alive,
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To learn more about the energetics of blue whales click the button below.
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