Originally Posted by Serpaeman
ok thanks. at my local pet shop they had both of these fish in probably a five gallon tank with three or four of them and a few other fish in with them. They both did fine. i might do the same. I also think that the serpae is nipping at the pristellas' fins. i will try and get some more tomorow and introduce them to each other.
Many fish stores could care less about the health of their fish, sad to say. You can never (unless the store is one that is run by aquarists who understand fish) go by what you see in stores. Not saying all are bad, many are very good. But...be warned.
As for doing fine, how do you know that? Are you a biologist with considerable experience in fish behaviours and physiology? Since I know you are not, I respectfully suggest you listen to those who do have considerable experience. The information in the Profiles, if you read it, comes from highly trained and experienced ichthyologists and biologists. It is wise to heed it.
You cannot have Serpae Tetra in a 10g. The fish itself is stressed, and the other fish will be stressed just having Serpae in there, even if they did no nipping. Fish release chemicals into the water, pheromones they are called, and other fish pick up on them. The stress all this causes to both fish--the Pristella because it is alone and is being nipped, and the Serpae because it is alone and is in too small a space--will weaken their immune systems and I can guarantee they will die prematurely.
How would you feel locked in a small room with a bully over whom you had no control? That is precisely what your Pristella is feeling. The fish can't escape its environment, as it would in nature, so it has to endure the torment and suffer the consequences.
Recently I posted a link to an article citing scientific evidence that shoaling fish kept in small groups are more likely to exhibit increased aggression, even in otherwise peaceful species. This is not someone's dream, it is scientific fact. And aquarists have a responsibility to provide an adequate environment for their fish.