A popular "well-known fact" is that all creatures on Earth consist mostly of water (i.e. H2O). Indeed, a liquid called "normal saline solution" is just a solution of 0.9% sodium chloride in distilled water. It is generally considered the "safe" liquid to be injected into human body in relatively high volumes without any bad effects.
I know that the same 0.9% solution is also used in vet practice for at least cats and dogs. As far as I understand, that's because blood circulation structure and basic blood regeneration specs are more or less the same for cats and dogs as for humans.
But what about other animals? My wild guess is that same 0.9% solution would be ok for all mammals (probably because their blood tract is similar), but what about others? Birds? Fish? Vertebrae? Invertebrae? Animals? Plants?
If 0.9% solution is not universal, what are the other possible variants? (i.e. could you provide examples of other compositions for some other species?)
If 0.9% is indeed universal, I'd be glad to hear any pointers on why does it happen (i.e. is it related to evolution of life in Earth history, is it related to chemical composition of bodies, related to some specific cells, etc).