Originally Posted by Timothy 1998 cremer
Yeah ive read about that before too but my discus seem to be chasing them away when it is feeding time and they usually never disturb the discus the discus swim around with them too sometimes so i thought id leave them with the discus.Does one of you know if their growth will be stunted if i leave them in the aquarium they currently are in? also i have heard that they will be fertile even if they are stunted is this true?
This is an example of what happens when the environment (in this case, tank size, fish species and numbers) is not good.
There are now scientific studies that confirm what many of us have long been saying, that too many fish in too small a space, or the wrong mix of fish, or the wrong numbers of a given species, will cause issues. Sometimes it is increased aggression, sometimes the opposite--fish not behaving normally. The discus are already stressed by the low numbers (they are a shoaling fish, unless you just happen by chance to have a mated pair) that need the group to interact and feel "safe" and in larger quarters.
The behaviour of the tetra may well change. They are too few in number so they are not acting "normally." But the time will come I can all but guarantee when they will turn nasty because of this, or alternatively they will weaken from the stress and be sick or die early. Either way, it is the environment that is causing it.
We cannot force fish to abandon their natural inherent traits just to suit our needs. The fact that doing so may seem to work now is no guarantee that the fish are truly healthy.
Last comment on stunting. This is when the fish is in too small a space (physical space for its needs and water conditions because of this) and the internal organs grow, or attempt to grow, while the external cannot. Stunting produces a weakened immune system and leads to health issues the fish would otherwise not have, and usually a premature death. This is simply not fair to the fish.