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Costasiella kuroshimae – Solar Powered animals, that do indirect photosynthesis
123 points by vinnyglennon 3 days ago | 49 comments
  • iwd
    I just got to see a different species of kleptoplastic sea slugs in the wild last month, on a kayak tour of the mangroves around Key West. Our guide scooped some lettuce sea slugs up in a plastic container (and then returned them safely). They were bigger, about 3 inches long, with a wavy/frilly green border. It made my biologist heart very happy!
    • throwup238
      That was likely a sea slug from the Nudibranchia order (they resemble lettuce sea slugs sometimes) which are a bit different from Sacoglassa order slugs like the one in TFA in that they carry symbiotic algae colonies, rather than digesting them and keeping the chloroplasts like Sacoglassa.
  • Ericson2314
    I remember as a kid wondering if we could give humans chlorolaplasts.
    • rustyhancock
      I believe that mitochondria and chloroplast both were originally independent single celled organisms.

      So kind of funny that, chloroplast is being "stolen" again by this sea slug.

    • gus_massa
      Somewhat related https://what-if.xkcd.com/17/

      The surface is too small and you only get like 4% of the energy you need (Assuming you like being naked under full sunlight all day long. The article is for cows, but I guess the number is similar for humans.) 4% of 2400 kcal is almost 100 kcal, that is the content of a small diet treat or 2 apples.

      These sea slugs can survive because they move very slowly. For a human, I think it's not enough energy to survive even if all the activity is to watch TV inside a hot swimming pool.

      • eigenspace
        Dietary need scales with volume, whereas incident sunlight would scale with surface area.

        Assuming a spherical cow and a spherical human, the calories needed would scale with the radius cubed, whereas the calories gained from sunlight would scale with the radius squared. So while I agree this wouldn't be very many calories, even if you sat under the sun all day, I think the 4% figure is probably quite pessimistic.

        • pfdietz
          The square cube law pops up all over the place, my favorite being in fusion reactors, where it is a two edged sword.
  • corygarms
    This is exactly why pokemon devs are looking for biologists! (seriously) https://www.nature.com/articles/d41586-026-00960-8
  • hackerbeat
    We‘re all solar—powered animals.
  • stavros
    Life is amazing.
  • makoai
    Real Life Bulbasaur
    • katspaugh
      Probably more like モンメン (Cottonee).
  • idiotsecant
    Makes you imagine a world with high solar power density and maybe lower gravity or something where larger land animals might be realistically supplemented by solar energy as well.
    • tbrownaw
      Closer to the sun (high solar power density) and smaller (lower gravity)... I think we actually have one of those nearby?
      • lukan
        Some infinite water supply would be probably helpful there.
        • tbrownaw
          Infinite indeed, need to keep it topped off as it all boils away.
          • lukan
            Now I think of a scifi setting, where rich people use massive ressources to feed their artificial gardens on Merkur with water from comets, so the genetically engineered solar powered green butterflies in their garden can keep flying.

            (But there might be more expensive adjustments needed, like rotation speed)

  • thinkingtoilet
    This is one of those times evolution doesn't make sense to me. It's clear how a giraffe's neck evolves, the ones that could reach higher leaves in trees had an advantage. In examples like this, how does this evolve when there is no gradual change? An animal had to exist that had an offspring that somehow both absorbed the chloroplasts of the food it ate in a way that it could use (not just simple digestion), then have a place to store them, then have a mechanism to move the chloroplasts to the storage space, then have the mechanisms in their body to use the energy the stored chloroplasts create. How does that happen gradually when each step is totally useless without the others?

    (please note I am not challenging the scientific truth of evolution, I simply do not understand how something like this happens)

    • crustaceansoup
      The article notes that the chloroplasts are like a larder that the slug can digest when needs be, so storage could have come well before photosynthesis was actually utilized.

      Or maybe it was photosynthesis first. The chloroplasts just did their thing for a while, and slugs that digested them slower (and eventually ones that stored them) got more benefit than ones that didn't.

    • largbae
      They look kind of translucent to me, maybe the first of this kind of slug just had a digestive problem that didn't break down the chloroplasts, and the minimal energy through their bodies made those individuals more successful because they didn't need to eat as often as those who digested theirs. Yada yada other errors among the indegestible-chloroplast population showed further advantages when it's closer to the skin, they outcompeted their peers, etc.
    • andy99
      > please note I am not challenging the scientific truth of evolution

      Evolution isn’t a matter of faith, you’re welcome to challenge it and try to poke holes in it.

      • dekhn
        While true, the predominance of evidence for evolution has reached the point that anybody attempting to argue against it would have to produce absolutely enormous amounts of self-consistent evidence that explains our observations better than modern theories of evolution. It's sort of like the laws of thermodynamics, or relativity, or quantum physics- if you found convincing evidence that any one of those was not accurate, and came up with a better explanation, it would both completely transform science, and open up new avenues for discovery.

        And if you want to do that, you should probably get a deep set of experience; otherwise, it's not much different from a flat earther.