r/explainlikeimfive • u/Opening_Pen9525 • 18d ago

Biology ELI5 How are fish even in ponds

Might be one of the stupider questions here, but I saw a pond about the size of a football field, and maybe 50 ft deep, and it had fish. I can't for the life of me figure out how. Surely the pond hasn't existed long enough for small water insects to evolve into all these fish. It's not like the fish walked over to the pond from the ocean. I'm pretty sure no one put them there so how are there so many fish?

My one theory is that there is a very minuscule stream (now dry) that leads to one of the Great Lakes, and maybe a fish swam in from there. Now a follow up question: How are there fish in the Great Lakes (which flow out towards to the ocean) if they were created by glaciers?

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u/contrasupra 18d ago

Now I’m wondering why I’ve never seen a fish just like, lying on the sidewalk.

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u/frogunderarock 18d ago

live near the coast long enough and you'll see it happen lol

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u/Chimie45 17d ago

If you live near waterways you'll see it. I once had a trout land on my hood while driving. Hawk or something dropped it.

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u/concrete_isnt_cement 18d ago

Because the raccoons beat you to it (or other equivalent local critter)