While playing, I thought about something interesting: From what I understand about Subnautica's history, the game takes place on top of an inactive volcano, in which its eruption that occurred millions of years ago promoted adequate living conditions in that region, and around it there is the void (ecologically dead zone) that supports only microscopic and leviathan-class life forms, so it is possible to theorize that in each volcano that has at least 4546B it has completely different life forms than other volcanoes. After that I thought about Sector Zero, and as I said, it must have life forms different from other volcanoes, but curiously, in Subnautica Below Zero we can find Peeper there, not exactly Peeper, but an evolution of it, adapted for the cold , the Arctic Peeper, there is also the Boomerang and the Stalker.

We don't have a map of 4546B, but I can theorize where the volcano from the first Subnautica is located. Well, considering that the two islands in the original Subnautica have tropical vegetation and throughout the gameplay the PDA doesn't talk much about the temperature, we can assume that the temperature there is a tropical climate similar to that on Earth, like 30-39C °, like the equator, and in Sector Zero, as expected, it is at the planet's poles. And both in the volcano and in Sector Zero there are Peepers and other animals in common, but wait, if there is the evolution of the Peeper in Sector Zero, then a normal Peeper had to be there to adapt and evolve, but how the hell does Peeper, Boomerang , Stalker, etc. left the equator to appear at the planet's pole? This would imply that Peeper and these other beings had to cross an immense part of the planet's ocean through the void, to then reach Sector Zero, and this is completely impossible, firstly, in the void there is no food, shelter, light, and other basic things for life, in addition, ghost leviathans are extremely aggressive even towards small beings compared to them, after all that you still have to remember that both Peepers, Boomerangs, Stalkers or etc. do not have a migratory lifestyle.

Perhaps the most obvious thing to think about is that the Precursors, while they were in 4546B and were researching the life there, ended up bringing some creatures from there, that would make sense, but the Snow Stalkers (the evolution of the Stalker) literally grew legs and left of water, and this type of evolution takes several million years, and we will agree that the Precursors were not here that long.

Anyone who has a theory to answer this can comment here.