Jack dempsey a killer?

Question

I just bought a lg jack dempsey and a lg Red Devil for my 120 gallon tank... I figured that he would be harrased by my lg Oscar for territory but I didnt figure on the JACK DEMPSEY killing my Oscar who was bigger.... Now he is attacking the Red Devil! I bought the 2 new fish outta the same tank of the aquarium store... why is he suddenly a murdering bastard? Do you think the Aquarium store will take him back? Or can I provide something to help the other fish stay safe?

Answer 1

Adding things like clay flower pots to the tank will help it to establish it own definite territory so that as long as the other fish stay out of its' own area, they will be left alone. You should also be using salt for freshwater aquariums at this point to protect the fish from infection. My local pet store will take all my tank raised fish off my hands (and usually give me some credit towards another fish) so I don't see why your pet store won't take the fish back if you decide to go that route.
A

Answer 2

It ain't sudden. That is the nature of the beast. You are talking about cichlids that get big and mean enough that an adult Dempsey is often kept alone in a 75 gallon tank. Most cichlids are aggressive by nature with a few that are not; Angel fish and Discus are examples of the exceptions with the Discus being actual cowards, but the African types are among the worst. The Oscars I have had are peaceful usually and they wouldn't do well in with the nasty characters you introduced into the tank. Even the small Convict cichlid can bully bigger fish in the tank especially when the little sex maniacs are breeding. As it is, the 120 might be big enough for the two of them but I wouldn't bet on it.

Answer 3

The problem is ciclids are very territorial fish,mixing them is a crap shoot! I've had fish tanks in the past with multiple ciclids in them and usually the fish that already have an established territory are the aggressors. you might want to try changing all your decorations around in the fish tank,so that the environment is new to the fish and they can reestablish new territories. Jack dempsey's can be very brutal, after all they weren't named after a boxing champion for nothing! You will have to check with the pet stores return polocy some pet stores have warnings about purchasing agressive fish, on the other hand if the person who sold you the fish guaranteed you the fish would get along then you might be able to return the fish. also Red Devils can also be very aggressive.

Answer 4

Petco will actually take it back within 15 days (i work there). Petsmart has a similar policy I believe.

I am actually surprised that your dempsey killed your oscar. That isnt very common but it does happen. You can get a divider for your tank to keep your dempsey & your red devil seperate for the time being. Once in a while you get a fish that (regardless of breed) is an anomoly within a tank. I am really sorry you lost your oscar! I am a big fan of oscars myself. Return the fish (or you can surrender it to your local petstore) or get a divider.

Good luck!

Answer 5

theres one rule you never add a fish to a tank after you have had another fish for along time territorial reasons I am surprised he killed your Oscar then again Oscars are friendly but can be deadly how big was he?

Answer 6

pet shop should take it back with the receipt. Tank divider will keep territories seperate which is why it is killing the competition.

Answer 7

cichlids are pretty aggresive by nature hard to believe that it would take out a reddevil though they're like one of the badboys of the family. as far as keeping the other fish safe i would take that jack and flush it .

Answer 8

fish shops usually don't take died fish back.
call and ask them if they'll take it back.

I do know that Petco gives you five days to return
dead fish.

don't forget that fish can be very territorial, if they
want room they will kill.