I assume whatever organs are used for the bioluminescence must be inside the baby's abdomen and specialized for bioluminescence and since the glow is gone entirely at 6 months, those organs must die off after 6 months of age.

I figure it must be a protein that is used for fluorescence, otherwise, the fluorescent molecules and thus the glow would still be there after 6 months. Growth leading to breaking down of fluorescent proteins into amino acids though makes perfect sense as to why the glow fades until at 6 months, its gone.

But how could hunger trigger the glow? Ghrelin levels have to be part of it since increased ghrelin is what causes hunger in the first place.

But the glow also happens to be the last cue that a Keplerian baby is hungry. Other hunger cues like these:

  • Open mouth
  • Sucking its hand
  • Rooting
  • Stretching

all come before the glow. Keplerian babies don't have a hunger cry and predators mistake the glow for something poisonous so this ensures both that the baby gets fed and that it is safe from predators.

But what could trigger the glow to occur later than other hunger cues? Could it be simply the level of ghrelin rising until a threshold is reached? Then once the threshold is reached the bioluminescent organs start glowing until milk gets into the baby's stomach which lowers ghrelin below the threshold and the glow stops as the baby suckles? enter image description here

  • 1
    $\begingroup$ What is it exactly that you're asking here? I noticed you've attracted a downvote already, and I think it's because we're having a hard time figuring out what your endgame is here. Are you asking how this feature would evolve or how it would work? I'm not sure either is entirely a good fit for the site, but reaching some clarity will help guide you, at least. $\endgroup$
    – Pleiades
    Jun 18, 2018 at 6:41
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    $\begingroup$ those organs must die off after 6 months of age Not necessarily, the gut biome changes, especially with new borns/babies. It's completely believable to have a 6 month period there. $\endgroup$
    – user3106
    Jun 18, 2018 at 8:38
  • $\begingroup$ What is a Keplerian baby? $\endgroup$
    – user3106
    Jun 18, 2018 at 8:40
  • $\begingroup$ For me this sounds a bit like a rhetorical question. Do you just need encouragement? Do you look for true alternatives? Do you want to know if what you are writing makes sense? Perhaps consider restructuring your question. For example, state what you think would work without question marks and then ask a good, answerable question about it. Just because I add a question mark doesn't mean it's a real question? $\endgroup$
    – Raditz_35
    Jun 18, 2018 at 10:59

3 Answers 3


Bioluminescense is a function of enzymes collectively called luciferins breaking down ATP and releasing energy as light.

As we see in fireflies, bioluminescense can be controlled by essentially the same mechanism as muscles. The depth of the mechanism is more than I want to get into typing in a cell phone.

In this scenario, glowing is equivalent to the extreme panic cry you hear from a human baby.


Here's one possibility: Keplerian babies are born with high levels of a bioluminescent protein, which they produce naturally at the same time as grehlin. This makes them glow. If you want the glow to happen only when the baby is excessively hungry then you could say that it takes a high buildup of the protein before the glow is visible to the eye. There is a corresponding enzyme in their mother's milk that combines with the protein and halts the bioluminescence. Over the course of the next few hours the baby's protein levels change so that the protein is once again at a higher level than the enzyme. This causes the baby to start glowing again. Why does this stop after six months? It could be a simple development switch - perhaps the body stops producing the bioluminescent protein. Another possibility is that the enzyme in the mother's milk may build up in the baby's body over time, so that eventually they don't need more of it. This would probably make the change more gradual - perhaps newborns glow extremely brightly and 8-month-olds still look a little brighter when they're extremely hungry.


Suggestion 1: Throw in a pheromone that wards off the predators. if they can see light emitted from a prey species, they will sniff prey and eat it. You need a strong chemical substance that makes a predator think "Poisonous"

The glow and the stink could be emitted by a mycotic colony living on the babies' skin. Then, like you said, after 6 months it just falls off the body

Glow would kick in only when the baby has been left alone outside for a given time. The mycotic colony reacts to the stress level and starts telling everyone "I am here, help me" without crying. Actually, this would be quite the advantage over the waste of energy needed to squirm and cry. The baby could actually live longer than his human counterpart


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