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Cichlid Territories and Aggression

Black DevilThis time around I want to talk about something I hold dear to my heart…aggressive cichlids. Most cichlids have a mean streak towards other fish in the tank, but its a whole different story when that aggression is turned on an unsuspecting aquarist.

Most of the species that exhibit this type of behavior tend to be in the South and Central American cichlid group. The African Rift Lake cichlids normally keep the aggression focused on other fish in the tank, though I’ve had some shell-dwellers who would attack my arms and on occasion rip out some arm hair…truly they can be like feisty little bulldogs. Some larger West Africans and cichlids from Madagascar have also shown brazen territoriality towards me in my many years of keeping them.

When people want aggressive fish, they tend to walk out of the store with an Oscar or a Piranha, but that is no guarantee you’ll end up with a “man-eater”. One thing my experience with keeping and breeding many different species of cichlids taught me is that they are all unique, and while one individual may cower in a corner, the next may show no fear or apprehension about chomping on a finger or some arm skin. I once read a cichlid book that said Firemouth cichlids were peaceful, so I purchased 2 pairs of 2 inch fish and put them in a 55 gallon tank. The next day I had to purchase a divider for the same tank to stop the carnage. I have spoken to many customers in the store about the fish they keep and the behaviors shown by those fish. Often, though they would share experiences opposite of my personal experiences with the same species. You can rarely tell how a fish will act towards you and other fish until you get it home to your tank and allow it to adjust.

In my experience, when it comes to aggression towards hands in the aquarium the trophy goes to fish of the Amphilophus family fish like the Midas cichlid and the Red Devil just to name a couple. The one that has always seems to become aggressive towards me is the Midas cichlid. Every single one I have kept has always gone after me and has even drawn blood, even fish that were “rescued” from poor conditions or surrendered by customers. The Trimac and Bleekeri from Madagascar are also consistently nasty in my experience. Although I have had many others threaten me with their stance like Firemouths and even a Red-hump Geophagus, but they were “all bark and no bite”.

A. trimaculatusRight now, my 5 inch Largemouth Bass likes to bite me when my hand goes into the tank to clean. Although it doesn”t draw any blood, when he hits the 12 inch mark I might be singing a different tune. Why are some fish prone to strike? The best reasoning is that they do whatever is necessary to guard their territory. I’m sure they don’t appreciate when we ruin their decor by redistributing piled and dug up gravel or replacing skewed plants and ornaments either. It’s their home, and we are not invited I guess.

Check out the video below that shows what happened to me when I had to work in the Colored Black Devil tank here at the store.

Angry Cichlid


Until next time,



  1. avatar

    You always have the option of changing who is dining on who with a large mouth bass. Have some beer batter made up the next time you clean your tank and see the attitude change.

  2. avatar

    Hallo Jose

    I would like to share a recent experience of an aggressive behavior of a Tanganyika species…
    Reading your post, I was remembering all sorts of aggressive encounters I had with my cichlids. From a male Phseudotropheus who killed the female after she did not want to lay eggs (for the almost hundredth time in a row), Convicts (IMO the most aggressive cichlid I ever encountered) up to the most aggressive Tanganyika Neolamprologus tetracanthus I experienced (Actually the only cichlid ever attacking my arm/hand). But following experience amazed me even more….

    I have some breeding Lamprologus Brichardi and when the little ones get bigger; they usually are driven out of the tank through the overflow and end up in the bio filter. From there I grow them little bigger and they go to friends etc.
    Well, I recently had two juvenile living peacefully together in the one compartment. As mentioned in your other Blog, I have built a 110LTR aquarium for 5 Brichardi and 5 Calvus.
    Now I caught the one juvenile Brichardi and put it in the new tank to see if the water would be safe. It was doing VERY well and the next day I caught his friend and put him together for the reunion…
    As the newcomer suffered a little, the first Brichardi started attacking the new one so viciously, that I was certain the new one would not make it to lunch time… He had the new one later lying on one spot and completely motionless. Only then did the “Oldie” leave the new one in peace.
    But as soon as the almost dead one, just made a move, Oldie darted down to make sure is is NOT moving.
    This went on for almost the whole day. Later that afternoon I started noticing the new Brichardi started spitting sand to make a small hole on the spot he was laying the whole time. VERY short “spitting” as if not to draw the attention of the other one! Still Oldie investigating each move but LUCKILY not attacking so strongly like before (the new Brichardi’s fins were already torn badly)
    The next day, to my very surprise BOTH were swimming together in the whole tank! And as I write, BOTH foraging the rocks…..

    Jose, for me this was a very new and interesting observation of aggression of actually a very peaceful Tanganyika cichlid!

    Having not THAT much experience as you, but hope you enjoyed a little!

    Best fishes and keep it cool


  3. avatar

    I used to have a tank with some Jack Dempseys and i found that if i made sure to keep some small feeders in the tank for them to terrorize they would leave the gravel and each other alone, the down side was that if one caught more feeders than the other i would wind up with one that was bigger than the other and then he would think he was the “big dog” and would mess with the others, but usually still left the gravel alone. but i never had a fish take a nip at me.

    I also had some snapping turtles that tried more than once or twice but its in their name what did i expect

  4. avatar

    Cichlids do not like to be messed with. I had an Oscar that bit me once and blood came out from my hand. She started to behave like this after I place a big filter in her tank. She somehow did not like anything hanging around her filter. I have also been bitten by Convict Cichlids that defend their spot, but their bites are bearable. 😉

About Jose Mendes

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That Fish Place’s resident “Cichlid Pro.” In addition to working at TFP for 13 years, Jose’s been breeding Cichlids for over 14 years and has produced over 200 different species. Jose is the man to question for everything cichlid. Check out Jose’s work in the article: Keeping and Breeding African Cichlids in Small Aquariums, and his many other contributions on cichlid husbandry, behavior, and his personal experiences with keeping cichlids from across the globe.