
How many aquarium fish are eaten by other fish, birds, aligators, otters, snakes and humans? Not very many, most people strive to keep fish predators away from their tanks.
What happens when a parasite attaches itself to a wild fish? Theres no one pouring medications into the Amazon so the fish gets infested and dies.
How many tanks dry out for 4 months of the year leaving the fish to take refuge in a muddy puddle with no food until the rains come again, if they are lucky enough to find a muddy puddle that is?
Aquarium fish have a far easier lifestyle than a wild fish.