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Help with my fictional species, blood colors?

ClearDragon

Troubadour
So, I've been making a race of anthro dragons, and I want them to have a different blood color then humans.
The thing is, they are supposed to have physical traits of strength and stamina and the color I want is blue!
Cobalt would do the trick, but it's much less efficient then iron!
So what element could be used the makes a different color and is as efficient at carrying oxygen as iron based blood? I'd prefer green or blue, but purple would be cool too!
Anyone have suggestions?
 

Devor

Fiery Keeper of the Hat
Moderator
Human blood oxygenates and turns red in the lungs or when you bleed, but it's often blue when inside the body.

I don't have a direct answer to your question. It's too sciencey for me. But blood and molecules are complex. Looking at just what you've written here, if you need a basic explanation for blue blood you can always say that in addition to iron it uses a small amount of cobalt to slow down the oxygenation process and help the blood to reach more cells before wearing out. The blood could appear blue just because of where the cobalt is located in the cells.
 

Corwynn

Troubadour
There are some real creatures here on Earth that have blood colours other than red. Human blood (along with blood of all mammals) is red because it uses hemoglobin, which is based on iron. Blood helps circulate oxygen through the body and when iron is exposed to and reacts with oxygen it turns a reddish colour, rust in other words. Some organisms use other types of blood. Your best best would be hemocyanin, which is copper-based and turns a green or blue colour when oxidized. There is also hemerythryn, which is iron-based, but has a pink or purple hue when oxygenated, and clear when it is not. These and other blood types are usually found in marine invertebrates on Earth, but there is no reason that any type of fictional creature couldn't have them.
 

skip.knox

toujours gai, archie
Moderator
You say the dragons have blue blood in the story and I'll believe it. It's fantasy. I won't be expecting an explanation and I probably wouldn't care to hear one, unless the story depends not merely on the color of blood but on a believable chemistry for that color.
 

Aldarion

Archmage
You may search "colours for alien blood", as sci-fi writers often dabble in that stuff (copper blood and the like).
 

Vaporo

Inkling
Human blood oxygenates and turns red in the lungs or when you bleed, but it's often blue when inside the body.

Actually, I believe that's a total myth that came about because our veins often appear blue when seen through our skin. However, it's just the walls of the vein that are blue, not the blood itself. Think about it. Even if you bleed underwater, it's still red. Your blood is always a varying shade of dark to bright red. Bright red blood coming from your lungs is highly oxygenated (even before it's been directly exposed to outside air), while dark red blood has had its oxygen depleted and is returning to the lungs for oxygenation. It's never blue, or clear, or any other color than red.
 
I have read many stories (be it in books or comics) that have demons with black blood, aliens with green blood (or blue or purple). And they have no explanation for it. It's fantasy and those beings are a different species than humans, so no one really questions it.

What I'm trying to say is go for it. Do you need an explanation in your story for it? If the answer is no, then go for it. If the answer is yes, then do some research or invent a new element or something in your world. It's your world, you are that story's first fan. Do you want dragons with blue blood? Have dragons with blue blood.

Also, when I think of dragons, I think red or black blood, I don't know why. I always associate red and black with dragons. By the way, some people consider purple the color of royalty and power. So maybe go for purple. Like I said before, it's your story. So, you decide. I hope this helped.
 
Do you want dragons with blue blood? Have dragons with blue blood.

I agree! But if the OP wants more science, the idea leads to some interesting possibilities. First, I am not anything more than an occasional fan of keeping up on hard biology and/or science, but it seems that if elements have been added to the periodic table as recently as 2010(?) then it's not out of the realm of possibility that, in your world, an undiscovered element might be pointed to as the key to the change in blood color. Perhaps carried in a long buried meteor that caused the offshoot when it struck the planet, releasing the element into the air for a limited time, say during the end of the dinosaur age, perhaps your dragons are the only survivors of just such a cataclysm, and they are the resulting race that exists in your world. Or the story may take place in an alternate history where science has yet to develop as ours has to have discovered the higher elements.

Also the old term "blue blood" has a very interesting history that might inspire your tale. If these creatures were pure of breeding, it could be that the striking cobalt blood color today is due to that bloodline maintaining its purity where, all other offshoots of life that came after, including humans (if they exist in your world), would be the result of the recessive or mutated gene or a change in the chemical structure of the blood and NOT the dragons. Make the dragons the purest breed on the planet. Make them proud of that (if the are the antagonists). If this story is set on our earth, it could be that the term blue blood actually came from these creatures and the true meaning got lost over time or, as is often the case in human history, was simply appropriated by noble human families to suit their own use.

And whether it is necessary to reveal any of the science is up to you. I suppose that would depend on the society and how pervasive the knowledge in it is of these creatures. Are they only reemerging after a long hibernation? Are they as geographically locked as something like the Komodo Dragons? Are they known to the everyday citizen and have they been studied by the sciences of your world in depth? Could go either way but unless it's not integral to the story, I wouldn't put too much emphasis on it being a hard science unless that's your goal with everything in the world.
 

K.S. Crooks

Maester
Copper compounds tend to be green or bluish-green. Many nickel compounds are turquoise. Most salts (metal with non-metal compounds) are white/colourless. However different metals do give flame different colours. Magnesium- white, iron- orange, potassium- purple, sodium- yellow, copper- green, lithium- red for example. Perhaps incorporate flame with the dragon blood to give it the colours in a scientific manner. It could be when a dragon's blood comes out it catches fire when it contacts the air, thus giving a certain colour. Or dragons could set their own blood on fire as a type of defence.
 

ClearDragon

Troubadour
I agree! But if the OP wants more science, the idea leads to some interesting possibilities. First, I am not anything more than an occasional fan of keeping up on hard biology and/or science, but it seems that if elements have been added to the periodic table as recently as 2010(?) then it's not out of the realm of possibility that, in your world, an undiscovered element might be pointed to as the key to the change in blood color. Perhaps carried in a long buried meteor that caused the offshoot when it struck the planet, releasing the element into the air for a limited time, say during the end of the dinosaur age, perhaps your dragons are the only survivors of just such a cataclysm, and they are the resulting race that exists in your world. Or the story may take place in an alternate history where science has yet to develop as ours has to have discovered the higher elements.

Also the old term "blue blood" has a very interesting history that might inspire your tale. If these creatures were pure of breeding, it could be that the striking cobalt blood color today is due to that bloodline maintaining its purity where, all other offshoots of life that came after, including humans (if they exist in your world), would be the result of the recessive or mutated gene or a change in the chemical structure of the blood and NOT the dragons. Make the dragons the purest breed on the planet. Make them proud of that (if the are the antagonists). If this story is set on our earth, it could be that the term blue blood actually came from these creatures and the true meaning got lost over time or, as is often the case in human history, was simply appropriated by noble human families to suit their own use.

And whether it is necessary to reveal any of the science is up to you. I suppose that would depend on the society and how pervasive the knowledge in it is of these creatures. Are they only reemerging after a long hibernation? Are they as geographically locked as something like the Komodo Dragons? Are they known to the everyday citizen and have they been studied by the sciences of your world in depth? Could go either way but unless it's not integral to the story, I wouldn't put too much emphasis on it being a hard science unless that's your goal with everything in the world.

Thanks, I'll consider this!
I'm going with blue blood. There will be some explanation, as their biology is important to the backstory.
 
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