Why do dragons have blood?

In the real world, blood is used to carry oxygen throughout the body, and at various points in the MSQ we see that the WoL and their friends seem to operate similarly, as they need to breathe to survive. However, dragons are capable of surviving in space, suggesting they have no need for oxygen. If that's indeed the case, does dragon blood have a purpose within a dragon's body?

Good question!

I have no idea whether we actually know the answer to this but I will offer a hypothesis that might make sense:

Dragons need oxygen still, but like whales and dolphins are capable of holding their breath for extended periods of time, possibly even years, so they can travel through space but need to land on a oxygen-atmosphere planet from time to time to take another breath.

Blood does a whole lot more than just delivering oxygen.

What if they can hold their breath for a very long time? I'm not trying to troll, I genuinely think they just may hold their breath for extremely long periods of time. Also they seem to be able to cross space rather quickly all things considered *cough cough endwalker spoilers*. But yeah hold their breath like a whale

Maybe they can hold their breath for months or years like Omniman.
Though the descriptions of Midgardsormr's journey made it sound like the journey took way longer than that.
Indeed, he started his journey well before the Sundering and arrived when it had "long since been sundered".

Something something, aether probably.

Midgardsormr probably put himself into a state of sleep to reduce aetheric emission during his long voyage through the expanse. My speculation of course being that things needed to sustain his physical aether like oxygen, food, and water, are less necessary in this state, especially given his penchant for napping for years on end without eating in game.

Blood is probably important to the circulation of aether within the body or something.

Quote:

---

Originally Posted by LilimoLimomo

In the real world, blood is used to carry oxygen throughout the body, and at various points in the MSQ we see that the WoL and their friends seem to operate similarly, as they need to breathe to survive. However, dragons are capable of surviving in space, suggesting they have no need for oxygen. If that's indeed the case, does dragon blood have a purpose within a dragon's body?

---

Better question to ask: does ffxiv run on the same physics as our universe when fundamental form of matter is 8-12 or so flavors if aether

There's no proof atoms as we understand them exist. No proof that oxygen is carried in red blood cells, bonded with waste carbon from cellular processes, and then transported back out to be exhaled.