system
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human
[ALIEN] Question about its circulatory system

If the alien/xenomorph has acid for blood, how is it able to circulate oxygen in its body? 
I know the movies never explained or explored the biology of the xenomorphs in-depth, but I'd like to have some sort of theory concerning its blood.
gpt
Xenomorphs don't need to breath and can survive in a vacuum.  They do need to eat though.   Because they don't need to take in air much of the function of a circulatory system is unnecessary.   The literature does explore the xenomorphs biology a bit, but doesn't give any solid answers other then they are very different from any other life form known by man.   It is also worth noting that xenomorphs are silicon based.