Aquaman #30: A Medical Review, part 2

May 18th, 2005

Filed under: Comics, Medicine

In Part 1, I took a look at the autopsy scene. This portion of the review is going to look at the rest of issue, particularly the scene where Aquaman confronts the semi-mad scientist Geist.

Geist: Well…because of the genetic mutation, everyone in Sub Diego breathes water – and they exhale air. It’s a…a byproduct of underwater breathing.

Geist: Y’know how you breathe oxygen and exhale carbon dioxide? Well, Sub Diegoans breathe water and exhale oxygen.

First, I’d like to remind Geist (and more importantly, the author) that due to his genetic manipulation, the people of Sub Diego breathe underwater using gills, not by using their lungs. There is no inhaling or exhaling at all.

How do gills work? They are very complex structures made up of thousands of tiny filaments which create a great deal of surface area for the water to flow across. They also contain many capillaries near the surface of the gills. As water flows across the gills, oxygen diffuses into the blood flowing through the gills. At the same time, carbon dioxide in the blood diffuses out into the water. Note that gills work constantly; there is no inhalation/exhalation cycle.

Pretty much everything Geist is saying is wrong and/or contradicts previously (and fairly recently) established “Sub Diego facts”.
1. The Sub Diegoans have gills, not lungs.
2. There is no inhaling/exhaling, no breathing in or breathing out.
3. Through their gills, Sub Diegoans extract oxygen from the water and return carbon dioxide.
4. As Scipio pointed out, if they are inhaling water and exhaling carbon dioxide, then they must be swelling up with hydrogen. Good thing nobody can light a match down there (oh, the humanity)

A few final thoughts:
1. If the Sub Diegoans were exhaling oxygen, they’d be very buoyant. In fact, the human body is quite buoyant naturally. How is everyone staying at the bottom of the sea without weight belts?
2. Why isn’t everyone’s skin all pruney?
3. While the Scrabble board is a neat trick, pencils work fine underwater; the trick is finding waterproof paper.

I would like to thank the Polite Sister, a SCUBA certified marine biologist for her help with this review. See what happens when you visit…you get pulled from your world into mine.

7 Responses to “ Aquaman #30: A Medical Review, part 2 ”

  1. Jim Kosmicki
    May 18th, 2005 at 10:37 pm

    Okay, I know that your new log is reminiscent of an old 80’s Comic Fanzine, but which one was it? I’m wracking my brain and can’t come up with it. It was one that the Thompsons were involved in, I think.

  2. Jim
    May 20th, 2005 at 1:32 am

    1. Aren’t there some creatures which have both gills and lungs? (The lungfish, maybe? Tadpoles?)

    2. They still started out as humans, so “breathing” is still a normal, autonomous activity. Further, as stated earlier, the humans’ gills seem to be small vs. body size, so perhaps “breathing” helps push water past the gills.

    3. The humans presumably stay at the sea bottom the same way fishes do, or something similar. If they’ve grown gills, they’ve probably grown all sorts of other “fish glands”, too.

    4. Pruney skin gets the same answer: the mutation.

    5. I don’t read Aquaman, so what do I know?

  3. Scott
    May 20th, 2005 at 9:36 am
    Official Comment

    1. Yes, there are some animals with both lungs and gills, but I don’t think it really applies here as it was shown early on that the Sub Diegoans cannot breath air, so their lungs pretty much just take up space.
    2-4. Could certainly be all genetic changes, but where’s the fun in that?

  4. M
    May 21st, 2005 at 3:25 pm

    Oooh! I was close on my exhaling nitrogen thing.

    Uh, breath-in breath-out…? Lungs don’t work with water, it’s too dense and viscous. It’s not energy efficient to suck it in, stop it, and send it back the other way through all those, necessarily narrow, channels. That’s why gills use a continuous one-way flow. Of course, there’s probably not enough oxygen dissolved in seawater for reasonably sized gills or whatever to sustain a warm blooded creature anyway (and that’s before we get into the rate of heat loss for a human in cool water), but we have to ignore that to have the story at all.

    Water in, oxygen out? Exo-thermic, not! Everybody now, post-elementary school fact callout; fish do need oxygen and they don’t breakdown water to get it, they use the small amount of O2 gas dissolved in the water.

  5. Carl Fink
    May 21st, 2005 at 10:06 pm

    Scott, you described filamentous gills in your article. Not all gills are like that — for instance, some arthropods have “book kills” that use flat membranes rather than filaments.

    Also, fish do breathe. They pump water over their gills in pulses, not continuously. Haven’t you ever watched a goldfish, and seen it opening and closing its mouth?

  6. Carl Fink
    May 21st, 2005 at 10:07 pm

    Book “gills”, sorry.

  7. Wanderer
    March 17th, 2008 at 9:39 pm

    Valid point on the goldfish, but the fish doesn’t technically “breathe”; the water is passed through the mouth, over the gills, and straight out of the body, so there is no “exhale” phase of the respiration. It’s why the term, “drinking like a fish” was coined.

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