CONTROLLING
                                                                                                        PETROCHROMIS
                                                                                                          AGGRESSION
                                                                                                Frank Schulterbrandt  11/30/2009

          The specie Petrochromis is a highly aggressive fish once kept in an aquarium.  You can’t get rid of petrochromis aggression , but you can control it to some extent. And unless this aggression is kept in check the results can be very disheartening.  Death can come rather quickly when petrochromis are housed in an aquarium. In fact petrochromis can kill almost as fast as you can cut through butter with a hot knife, well not quite as fast.

         Petrochromis aggression can be handled by different approaches. One way is to disperse the aggression through having a good stocking level
of petros in your tank (see Petrochromis Stocking Levels). Another way is to generate a good current flow of water in your tank.  And yet another way is to have a lot of hiding places and plastic plants that also create a lot of hiding places. Finally not having any rocks , caves , etc. will eliminate the conflicts that petros have when trying to establish a territory for themselves. 

        In a 125 gallon tank I had 2 trios of Petro Longola , 2 trios of Petro Moshi, 1 trio of Petro Tri-Color. In this 125 gallon tanks the landscape consisted of many rocks and plastics plants at both ends of the tank. In the middle was a few giant 36 inch plastic plants and one large rock.
There was still some aggression from the Alpha Longola male. The Longola would break up the breeding routine of the Moshi and the Tri-Colors. Here  is an example of what the Alpha Longola would do. After the mating ritual of the Tri-Colors the female would release an egg , then the male would release his sperm and then when the female would go to pick up the egg the Alpha Longola male would swoop in and eat the egg.

       This is what I have done to the 125 gallon tank to try to eliminate this behavior by the Longola male.  First I removed all of the plastic plants,
 I also removed all of the rocks. I performed a 50 percent water change. I also placed a 3200 GPH Dual Wave Maker (Sun Sun power head) at one end of the tank. I then added 6 more Longolas which I was able to get really cheap. I also added 2 Petro Macrognathus Zambia. I have noticed a big change in the behavior of the petros in this tank since I have made these modifications  to this tank. The petro are swimming as if they were Malawi Mbunas. Sure there is the occasional aggression but a big difference from the original setup. 

      So this is what the 125 gallon tank looks like now. The tank have gravel, Rocks at each end of the tank. One large rock in the middle of the tank.
Filtration consists of an XP3 canister filter. Two power heads connected to the under gravel output stems and airline connected to the remaining under gravel output stems. One Aqua Clear 110. There is also one sponge filter and one air stone and the Sun Sun Power head.  I may make one more change to this set up. Perhaps n the future I will remove the gravel and the under gravel filter and replace it with a sand and gravel mix. I have always used under gravel filters because of the beneficial bacteria bed, this allowed to make massive water changes.   

     So Aggression was controlled to a manageable level by increasing the petro stocking level , adding a good water current from a power head and landscaping change. And yes the Tri-Colors have bred , this time not being interrupted by the Alpha Longola male.

     I have also noted that if you feed pellets as opposed to flake food there seems to be less aggression. This may be a result of providing more food
to your petros via pellets. This perhaps can also be accomplished by feeding more flake food at feeding times or increasing the daily amount of times that your petro are fed.

     At this time I have also re-introduced the wounded now healed petro back into this set up. I like many petro keepers was having many failed attempts trying to reintroduce the now healed petro back into the group. Although a lot of work in this landscaping project, this new setup procedure seems to be working. At this time I have made similar adjustments to other tanks. For example a 240 gallon tank now has a Koraila 8 the Koraila 3 has been replaced providing much more water current.

    Aggression must be controlled so that you can enjoy these Tanganyikan beauties…. So I wish you GOOD LUCK.