Of the Blood

Now for starters, marine mammals do not have gills.

I can let this go however because it’s comics and not a marine biology textbook. But here’s another problem:

no one can agree were their gills are. 

I’ve seen them just behind the ears, on the neck and now I read near the clavicles. Only once have I seen them drawn as just part of the design and that was part of the 2003 run I refuse to acknowledge.

Just behind the ears makes no anatomical sense at all so we’ll ignore it. The other two are much more viable so we’ll look at that. Basically, gills work by taking oxygen from the water passing through them via the capillaries in the tissue contained in the gills. Given the nature of these structures the clavicle is not a viable location so that means that atlanteans should probably have gills on their necks. 

Gills are very sensitive and delicate. Just touching them can stun their owner, more then that can put their lives at risk. Atlanteans cannot go in chlorine pools as the chlorine burns their gills but can survive in freshwater just fine.

Speaking generally, the sea can support life on massive scales, just look at whales. There’s advantages to that kinda of size when it comes to swimming and when you look at swimmers they tend to be fairly tall. So I’m putting the rough general range for Atlantean range at roughly 6”5’ to 8’ for men and like 6” to 7”8' for women. Namor as a hybrid is on the shorter end at about 6”6’-6”7’.

Their arms and legs are proportionally longer then a human’s and their shoulders are very broad. Their hands and feet are also proportionally larger then human hands. Atlantean eyes have a transparent membrane that covers, protects and helps the eye adjust to seeing things out of the water. This membrane does this automatically when they leave the water. Atlanteans have excellent night vision from living at the depths of the ocean. Their eyes are more sensitive to the green portion of the spectrum then human eye which allows them to see more acutely in the dimly lit ocean depths.

Canonly, atlanteans can only survive out of the water for a short period unaided, generally about 10 minutes. However I don’t think that quite makes sense since they should still have lungs since they’re mammals. However, I don't think they're really used for their original function anymore. My thought is that the lungs now generally serve as the swim bladder, an organ full of air or gas used to control buoyancy, for atlanteans.

When out of the water they can function as normal lungs but as their owners have never used them as such they can struggle to survive. Even if they manage to get their lungs to function as lungs it can take a very long time to reach a level where they aren’t consciously thinking about breathing. They run a real risk of suffocating while they sleep. Atlanteans have made various solutions to this problem now so it’s generally not a problem anymore. However, they prefer to not go on land at all and stay to the seas.

Atlanteans are over all more durable then humans given the conditions they have to live in. They are able to survive incredible pressure and pressure changes. Generally, atlanteans are 10 times stronger then humans and can swim at a max speed of about 30 miles per hour. Since they are mammals, they’re warm blooded and their superior blood circulation enables them to withstand the near-freezing temperatures of the ocean depths and tolerate the heat of thermal vents with minimal discomfort. They are one of the longest lived mammals with a life expectancy of about 150 years.

Atlanteans are entirely hairless except for the hair on their head which is vestigial at this point. Many simply shave it off as it’s more troublesome then anything. They have developed blue skin to allow them to blends into their surroundings better. Hybrids have a skin pigmentation mutation that changes their skin color from blue to human skin tones and visa versa. It’s unknown if there’s any trigger to the process as there have been few known hybrids.