> Since no one had seen fish having sex, it was believed that fish spawned spontaneously from rivers/lakes/oceans and therefore were free from the animal version of "original sin".

I don't know who comes up with this stuff.

Aristotle wrote extensively about fish eggs, milt and breeding habits centuries before the Christian era. Not only that, fishermen throughout history were well aware that fish laid eggs.

On the other point, original sin applies exclusively to humans. Animals were never considered moral agents, nor were they subject to the Fall of Man in a way that required spiritual redemption.

> sauerkraut and kimchi are both pickled cabbage

Yes, but one uses Brassica oleracea while the other uses Brassica rapa.