Female Cichlid Turns an odd color

Question
Hi!
Thanks for taking the time to answer my question!
My husband and I recently bought a 30 gallon tank recently. With it, came three convict cichlids  -  2 males and 1 female.
They seemed to act pretty mildly together (not much fighting, etc...). We were prepared for some issues but everthing seemed to go pretty smoothly. In which case, we decided a couple of days ago to purchase a couple more to add to the tank. The pet shop we purchased from suggested a Firemouth and a Jack Dempsey. We brought them home and got them used to the tank through the bag for a few hours before putting them directly in the tank.

My question is... My female convict has suddenlly turned extremely violent, attacking all the other fish. It seems to be the only one causing trouble, and has also turned completely black in color. Is this normal stressed out behaviour? And if not, can you suggest another possible reason?

Answer
Hi Amanda

These are all pretty aggressive fish. When placing aggressive Cichlids together, it's best to add them all to the tank at once, and that they all be close to the same size. The behavior you describe is pretty common among Convicts, especially females, and especially when breeding. A breeding pair of Convicts should be separated from the others as they can kill other tankmates.

Firemouths and Jack Dempseys will hold their own against Convicts. However, if there are 3 Convicts and 1 Firemouth and 1 Jack Dempsey, they could have a problem. Try rearranging the tank decorations and possibly adding a couple of new decorations. This will disrupt their territories and usually solve the problem. If they continue with the aggression and it gets to the point where one is injured, you may need to separate them.

Hope this helps, good luck!

Richard