I think for me it highlights present man's disregard for any moral or ethical question.
Stocking yet another species of fish into your commercial pond, you must question the effect this might have on fish already there, you must also question, particularly with a species such as the barbel, the impact on that species once stocked. It seems ludicrous that it's ok to stock a fish into a commercial pond having been so evolved to live it's life in a river, knowing full well that that fish cannot breed in that pond.
It's like taking a species of monkey, so evolved to live it's life in a tree, and putting it in a savannah just for your admiration and enjoyment. You are playing with that species physiology.
Consider for a minute that the species of monkey you introduce to the savannah is able to reproduce, then think of all the changes, if it is able to find enough to survive well enough, that that species would go through. Who are we to play with such things?
This planet and everything in it is not ours to do with as we please.
Damian
Sorry Damian, but neither of those points stand up.
A commercial pond is an enclosed environment, it makes absolutely no difference to those barbel whether they breed or not. If the barbel is able to find food and isn't out-competed by other residents it will do very nicely. Studies have shown this.
A monkey in the savannah is a completely different prospect. Most monkey species have evolved very specific food source dependence and the vast majority would die very quickly from a) starvation and b) predation.
Unlike the pond-stocked barbel.
There is no argument from a physiological point of view why barbel cannot adapt to stillwaters. The evolutionary adaptations have less to do with running water and more to do with bottom feeding.
There are 100's of types of similar "running water" species kept (and bred) in home aquariums that, in essence, are no different to barbel in terms of their environmental niche. E.g. Corydoras.
If you'll excuse the phrase, the old "riverine evolution" argument holds no water.
We've all been through this "debate" a thousand times before, so I've said my "anti" bit to redress the balance and that's as far as I can be bothered to take it. :wh