So after reading over other blood colors and the benefits of other blood bases I wanted to create a species that used Coboglobin instead of Hemoglobin. Though based off of Jim2B presented of,

enter image description here

On this chart it shows that Coboglobin is most effective at 15 Celsius body temperature and a lower partial pressure than Hemoglobin, (Still not sure what that means yet, but meh.)

With that information my question is what kind of environment would produce the most effective use of having such a low internal body temperature and lower partial pressure. (Assuming that it would be a warm bloodied creature.)

  • $\begingroup$ Lower partial pressure means either lower pressure or lower %. Basically partial pressure of oxygen is pressure of air multiplied by what part of air is oxygen. In normal conditions this gives ~0.21 atmosphere ≈ 213 hPa - 21% of atmospheric pressure. $\endgroup$
    – Mołot
    Jan 23, 2017 at 18:42
  • 2
    $\begingroup$ Partial pressure is the pressure exerted by one particular gas in a mix. For example, at 1atm and 21% oxygen (our atmosphere), oxygen exerts a partial pressure of 0.21atm. If you were at 2 atm, and 11.5% oxygen, the partial presurure would also be 0.21atm. $\endgroup$
    – Cort Ammon
    Jan 23, 2017 at 18:44
  • $\begingroup$ You also might want to look at Hemocyanin which is used in some arthropods and is blue in color. $\endgroup$
    – John
    Jan 23, 2017 at 18:55
  • 1
    $\begingroup$ Ah, I think I get that part then. Not so great with stuff, so I figure the easiest way to do that is that if our atm. is 1, and made of of 21% oxygen, then it is .21 partial pressure. So increasing and decreasing the oxygen percent level in the atm. is the same decimal change... Erm, so a .1 partial pressure is an atm. with 10% oxygen? $\endgroup$ Jan 23, 2017 at 18:58
  • $\begingroup$ Yes, you got it right. $\endgroup$
    – Mołot
    Jan 23, 2017 at 19:17

1 Answer 1


For low pressure and cold a fictional biotic Mars would be a good choice. Even with an oxygen atmosphere it would have lower pressure and be colder. On earth tundra plateau would be good.

But really almost any oxygen environment will work, it depends more on the animal you build around it. There are several different oxygen carrier in the same environment on earth becasue they all work good enough. The other anatomy of the organism has WAY more impact than the oxygen carrier. Things like circulatory system, hox genes, support structures are far more important.


  • 1
    $\begingroup$ Ah, thank you for showing that info-graph. I already have an idea for the species built up that many of the already asked questions here. Just playing around with variables. And with a thing like Coboglobin being effective, I figured that would make things like Haemoglobin or Haemocyanin less effective. Because if the environment was cold enough to warrant a warm blooded creature to have 15 Celsius body temp. then something of the same mass and what not would have to spend more energy having Haemoglobin, etc... Haemoglobin would be better with partial pressure. Thanks for helping my process. $\endgroup$ Jan 23, 2017 at 20:19
  • 1
    $\begingroup$ keep in mind much like the other oxygen carriers Coboglobin could drastically change its optimal temprature with small changes to the protein. Alos keep in mind if your creatures give live birth they need more than one form of oxygen carrier just like mammals. Fetal hemoglobin has a stronger oxygen binding becasue it has to pull oxygen of regular hemoglobin. $\endgroup$
    – John
    Jan 23, 2017 at 23:15
  • $\begingroup$ True, that change was probably going to be my next question, for now I just wanted to know what the optimal environment for this kind of blood to arise. Though that live birth presents some interesting issues. Guess I would have to look more into that even though there is not a lot of information on Coboglobin compared to the others that are used on our planet. $\endgroup$ Jan 24, 2017 at 0:40
  • $\begingroup$ Just having an oxygen carrier is such a big advantage that it really doesn't matter it it is optimized or not. for instance an organism that does not have an oxygen carrier would rely on dissolved oxygen in water, that severely limits how much energy they can use. Suddenly having an oxygen carrier would be like suddenly have dozens of times as much food, it would open up a lot of options. $\endgroup$
    – John
    Jan 24, 2017 at 15:14
  • 1
    $\begingroup$ Ah, interesting perspective on just having an oxygen carrier. And more things to consider, hmm, well I do want it to be all hammered out information wise. I figured that creatures evolved to make the most use out of their systems like blood based of off what they had available in their environment. Though there are a lot more things to think about know, your help much appreciated. $\endgroup$ Jan 24, 2017 at 15:32

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .