The Chronicles of Riddick (franchise)/Fridge

• Fridge Brilliance: At some point in Pitch Black, the creatures turn on each other and become cannibalistic. Well, considering they have to wait 22 years just to feed'...
• Fridge Logic: Pitch Black. Why are there no plants? At all?
  • There was considerably less oxygen on M6-117, which is why they used those breathers; more likely than not, there were plants underground that simply didn't get as much oxygen to the surface - only enough to keep humans (barely) alive.
  • Except plants only make oxygen when they're photosynthesizing, which requires light. More likely there are areas of the moon that do have plants, we just didn't see any because the ship crashed in a desert.
  • This is an alien world we're talking about. It is possible that on Hades/M6-117 that animals and plants never split off during their evolutionary course; which would make sense, considering how barren and harsh that world is. For all we know, the Bioraptors may have been part plant; and it is possible that they produced oxygen. There are deep-sea plants that can grow without sunlight; and there have been many cases of plants with animal-like tendencies on Earth.
  • But wait, there's more: How did the Bioraptors, who can be killed with prolonged exposure to any light at all, even evolve on a planet where the Suns only set once every 60 years?
  • Imam states that the Star System Hades/M6-117 is in gave him the impression that Night lasts just as long as day does. There were probably Durnial (Day-light) creatures that went into hibernation or stasis for the long Night and could not survive otherwise elsewhere on Hades; while the Bioraptors were in the opposite case. Their adaptation more resembles an animal that hibernates during winter than, say, a Bat that only comes out at night.
  • Nope. Remember, the geology team was there 22 years before, and had no lights in the camp because it was always light out. The movie made it clear that it was an eclipse, not just the suns setting. So there's no way those things could evolve with one eclipse every 22 years.
  • I got the impression that the moon was hollowed out, kind of like a honeycomb. There is probably a complex ecosystem below the surface. The bio-raptors merely come to the surface during darkness, probably to breed, away from all the other badass predators, and in the frenzy they kill each other. Would also explain why those larva things were bioluminescent. If light harms the bio-rapters, then there is a disadvantage to eating those larva, which could be bio-raptor young.