Suggestions for an overly aggressive fish?

[SouthTxAquaman]

sorry if this has been covered a lot in the past, I didn't see anything on it yet in the forum. And let me preface that I know many mistakes were made here.

I purchased a female jack Dempsey yesterday from my lfs. She's maybe 4.5 inches. I put her in my 2nd tank to watch her a bit. I should of removed the other fish in there before hand, but I was excited to get her in and see her in better lighting. I noticed a few hours later that my oscar (about the same size)in the tank had a few marks on him. Stupidly, I dismissed it as a quick territorial dispute. Soon after I found my black Moore (yes extremely odd combo of fish, it was very temporary) severely beaten. She had ripped its eye clean out of its socket and eaten it. I removed her from the tank and put her with a male convict much larger than herself who is a pretty chill dude. Sure enough she attacked him, but this time got her tail handed to her.

In summary, I made a series of bad choices and ended up finding out this JD is very aggressive.

Which brings me to my question, any ideas on how to condition a high strung lady JD to not wage war on her tank mates? I'm hoping the fight with the con will calm her down but idk if they will continue to fight or if she learned her lesson

 

[Astro Boy]

Wow! Putting her in with larger tankmates or those who can handle themselves like your convict will help. Ultimately a hierarchy will form and things will be put in their place. The problem may be if this lady ends up outgrowing the others and then may end up being a bad boss.

 

[SouthTxAquaman]

yes that's kinda what I was thinking too. I was crossing my fingers for another answer, as at the moment she is bigger than all the tank mates I had planned for her (other than the convict). The oscars will outgrow her eventually but the other JD I have is probably an inch behind her so it will be a long time before he catches up.

She's extremely timid right now.

 

[Ogertron3000]

Maybe just needed a good beating to learn her place, normally it's the established fish being aggressive not the newcomer so all the usual methods like rearranging tank decor and lowering temp probably won't help. Might just be an ultra aggressive fish in which case there's not much you can do.

 

[Backfromthedead]

you probably dont want to hear this one but bigger tank maybe? they seem to get pretty territorial around 4". I've been unsuccessful at integrating aggressive cichlids in 75 gal tanks...looking to rehome an aggressive jd atm myself. idk what size tank youre working with though...

 

[Gourami Swami]

Tank size is a big factor, in small tanks aggressive fish won't work with tankmates well. The JD also might just be a real nasty one, not much you can do about the fish's personality.
In a big tank, with enough tankmates, the aggression will be distributed. But mixing aggressive cichlids is a balancing act, you can do some things to make it easier (like big tank, one sex of fish, target fish) but there are no guarantees anything will work really. This JD might just not want tankmates.

 

[Deadliestviper7]

Try adding cover such as driftwood and fake plants to the tank,this can help minimize aggression

 

[TheWolfman]

That’s why there called Jack Dempsey’s. I had to get rid of one because of that. A impulse buy gone wrong for me. I hope it works out for you.

 

[Allan01230]

I have a male JD that is about 9 inches and very aggressive I have him in a 50 breeder all by himself

 

[duanes]

The name Jack Dempsey refers to a champion boxer of the early 1900s.
There is really no way to temper its aggressive nature, unless as already stated, its in a large tank,
In Mexico, where they come from, they do best in Cenotes where no other cichlids are present, and there, a pair will guard an area equivalent to about 250 gallons.
Here is a video from their habitat.
Eden2