Newcomer Looking For Advice

[Ambaryerno]

I was definitely considering aquatic plants, and will definitely consider things like those hyacinths (ideally I'd like to use as much as possible that would be native to the environment). I was also thinking about aquatic microfauna as well (like those little freshwater snails). Would the crayfish idea in the OP be too risky IE (snake eating the crayfish, crayfish injuring the snake)?

There was definitely going to be some sort of separator between the land and water area.