Any ideas on whats going on?

[Clark16]

so about a week ago i put a horned blennie in my tank and my blue velvet damsel and my black and gold cromis did this move where they backed into my blennie with there back fins. The next day i found him dead at the bottom of my tank. today i got a lawnmower blennie and they are doing it to him. I was wondering what this action means and I def dont want to wake up tomorrow to find the same thing. Anyone have an idea of what is going on?

 

[TooTime]

That is a form of aggression that your two fish are doing to the new ones. There are a few things that you can do to help with this. One is when you add a new fish turn out the lights and leave them off for a day so that the new fish can get acclimated in peace. You can move around the rocks when you add a new fish, this will make them all look for a new area to claim and may help your new one acclimate as well. You can add more than one new fish at a time to help spread out the aggression. You can buy an acclimation box or use a specimen cup to keep your new fish from being picked on. It may help to put a mirror up next to the tank that way the fish mess with it instead of the new fish. You can try to add the new fish and make sure they are bigger than the old two. These are all suggestions and things that I have done in the past with new fish to try and stop or slow down the aggression. Good luck...

 

[Clark16]

thanks so much for the tips i just turned out the lights and i will get a mirror as well and the blennie is twice the size of the damsels so i dunno and i also put a couple new pieces of rock today. But next time ill make sure to get a couple fish. I also have a tomini tang and he is chasing the blennie everywhere so hopefully the lights off will help