Why are whales so big?

Answer 1

I think Lani's got it on the nose. The surface-to-volume ratio goes down as the size of an object increases, so bigger animals have a larger volume to hold heat, and a smaller relative surface area to lose it through. Large fat reserves that increase size also serve to both insulate and store energy and water. Larger size also allows predators to attack larger prey (like giant squids) and prey to become less vulnerable to attack.

Answer 2

Good question... but not all whales are big (and big is a relative term). What about the Psuedo orca that is smaller than the Atlantic Bottlenose Dolphin?

But I am assuming you are talking about Mysticetes, and there are several reasons why they have to be big.

Lung capacity needs to be high in order to dive to the depths they commonly dive to - big lungs needs lots of space.

Need lots of blood with lots of oxygen carrying hemoglobin. Lots of blood needs lots of space.

Reproductive demand is high- need lots of resources to make gametes and offspring.

Need lots of blubber to protect against the elements - both cold and warm.

Bouyancy becomes easier when your density is lower than that of the surrounding water in the column.

There's plenty more answers - look in a Marine Bio book!

*Edit* For those who said it has to do with their diet - most Mysticetes (which are the larger of the two orders of whales) eat the smallest things in the ocean - Phytoplankton and Zooplankton. So it has nothing to do with diet!

Answer 3

It's not entirely clear why whales are so big. Probably the reason is that having a large body size being a great way of generating and holding heat. This is particularly important in the ocean where the cold water can zap body heat up to 20 times faster than on land. That would mean their big sizes allows them to stay in cold water without dying of coldness. Size also means that they can store lots of fat so that they have big reserves of "food" to get them through the winter when they migrate to
warmer waters. Whales may not find food on winter while on ,migration so they have to rely on the fat that they've built up during the summer feeding season.

Answer 4

its not actually that big, its only a fraction the of the size of England!

Answer 5

Its from the dinosaurs era and there greedy they eat everything they sea.what i thought it was good lol

Answer 6

well .. there are two theories... neither of which i subscribe to, i believe that adam and eve played a joke on god by giving a normal fish "Gigantor" pills.. and that is the result.

Answer 7

Global warming perhaps.

Answer 8

They eat far too much!