donnasummer

i added a few new fish to my 4ft tank 4 days ago and it really shook up the tank, my once placid black red tailed shark has started to become very aggresive to the extent that he has stressed one of my exsiting pink kissing guoamois, the tank has settled now although the shark is still making all the others aware that he is boss, but my guoamois has been practically motionless and hiding ever since, only coming out to eat a small amount of food, the other kissing guoamios does not seem bothered by the shark, i am really concerned about him, will he get over this and eventually come back round? he has been living in the tank with the shark for at least 2 months without any problems.

Newtankdude

I think the shark got aggressive because it's defending its territory, you might have too many fish.... That or the gourami invaded the sharks space and now the shark turned into a bully.

Carillon

Unfortunately, gouramis are notorious for being shy, and yours may be no exception. When they are kept with larger, more boisterous or more aggressive fish (like your shark, perhaps?) they often become quite reclusive and shy, and spend much of their time hiding. I can't attest to the sudden change in behaviour, but it may be that the gourami was taken aback by the sudden aggressiveness of your shark and has now decided that the tank is simply not a safe place for him anymore.

I'm not sure whether your gourami will come back around on his own or not. It may be that he will just continue to hide for a while and will then come around, or he may act shy indefinitely or until the shark is removed. You can increase your chances of coaxing the gourami out by adding some more plants to your tank, especially floating plants. These should darken the tank a bit, and should make the gourami feel safer.

Good luck.

donnasummer

thanks for your reply, unfortunaley the guoamois did in the night, we are currentley trying to catch him to put him in isulation for a while to see the affect on the rest of the fish, but it is easier said then done, we tried for 2 hours last night and gave up, perhaps if we had persisted we coulc have saved our beloved and rare large guoamois!