ELI5: How can sperm whales dive so deep and not suffer from the pressure?

Read the Story

Show Top Comments

Whales have numerous adaptations to help deal with pressure. Firstly, they have a reduced number of sinuses and air cavities compared to land dwelling mammals. Where they do have cavities, these are heavily lined with blood vessels, which fill at depth, blocking the airspace completely and preventing its collapse. Secondly, their lungs can collapse without suffering damage, due to reinforcement. This has the added of effect of preventing gas exchange with the blood, which prevents nitrogen narcosis and ‘the bends’. This naturally also means that they can’t get oxygen from the lungs too, so they have evolved changes to their blood and muscle to cope. Whales have a lot more blood per kg than land mammals, and much more haemoglobin, which stores oxygen, in that blood. They also have much more myoglobin, the protein that makes red meat red, in their muscles. This again stores oxygen.


What if they grab a squid at depth and beeline for the surface? Can squid survive the decompression?


Sperm whales in particular have a thick, milky, substance in their head that helps them deal with the pressure. When whalers cut them open it would pour out onto the deck and (not sure I would tell a 5 year old this, but…) it resembled ejaculate, hence where they got their name, the Sperm Whale.


Reading the composition and wording of this title, I was almost positive it was posted on r/jokes. đŸ˜‚