Name: TED-ED】シロナガスクジラはなぜ巨大なのか？- アーシャ・デ・ボス (【TED-Ed】Why are blue whales so enormous? - Asha de Vos)
Uploaded: 2021-01-14T04:37:36.000Z
Duration: 5 min 21 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

上級比較級を表す句型

They're at least two times as big as the biggest dinosaurs,

by feeding exclusively on tiny shrimp-like creatures called krill

that are no bigger than your little finger.

seems to have driven the evolution of the blue whale.

Basically, the whale accelerates towards a prey patch

To increase the capacity, its mouth expands.

The special, accordion-like blubber layer

that extends from its snout to its belly button

enables the whale to engulf large quantities

the whale takes in 125% of its body weight

the comb-like structure made of the same stuff

It's pretty crazy that the blue whale's heart

a child could crawl through its arteries,

its tongue weighs as much as an elephant,

the whale could choke on a loaf of bread.

It's estimated that blue whales eat four tons of krill per day.

Every mouthful of krill provides almost 480,000 calories,

the same amount you get from eating 1,900 hamburgers.

than the largest living land animal, the elephant.

there's a point at which the legs of that animal

They need legs shaped like stout pedestals

In water, the situation is quite different.

Buoyancy counteracts the gravitational pull on the body

and their great bulk is therefore partially supported

So, the ocean is a great place for species

The other secret to their size is their diet.

the whale's have specialized to catch enormous quantities

which provides the energy needed to grow so big.

Well, while lunge feeding may have allowed blue whales

by enabling them to feed efficiently in dense prey patches,

Scientists compared all the costs involved with lunge feeding

to the energy gained from the krill they eat.

What they found is that when the whale's body increases in size,

the energy that body demands rises faster

than the extra energy they get from their food.

Feeding whales needs 15 times the energy required to remain still

and 5 times more energy than used when swimming.

that the largest a lunge feeder can grow is 33 meters,

Turns out blue whales have a lot to thank krill for:

that would not have been possible if krill were not so small.

It's incredible that these tiny creatures

have allowed blue whales to really push the limits