Aggressive Convict Cichlids

  • #1

I previously owned a full grown pair of convict cichlids that I kept in my 10g. They were definitely male and female but as soon as I put them in the tank they both started beating each other up and killed my angel within minutes. I wasn’t sure what to do so I put a divider in the tank. They were both the same size. The night after I bought them the female jumped over to the males side and killed the male. So I left the female by herself and then moved her to my 200 gallon tank which had a young flowerhorn and a pair of angels in it with some plecos. The flowerhorn had a quarter of the tank to himself with a mesh divider that was large enough for the plecos to go back and forth between. The female convict was fine for a few days and then jumped over to flowerhorns side. The flowerhorn was slightly smaller than she was at the time. I left her in there and they began to show signs of breeding which I didn’t want so I took her out and put her back in the angels side of the tank. A day later she jumped over again and began to fight with the flowerhorn. After a few hours my flowerhorn was missing some scales and had a few ripped fins so I took her out and returned her to my LFS that I bought her from.

Now one of my friends gave me a pair of his convict fry that he bred himself. Before I got them the whole batch of fry were in their own tank that had two sponge filters in it and plane substrate with no decorations. He gave me what he thought was a pair but they are still very small, 1.5 cm. One is slightly larger than the other. When I put them in my 12g planted tank with snails and a coconut hut the slightly larger one began to terrorize the other. The tank is a 12g bow front which is heavily planted with amazon swords and a very fine sand substrate. There aren’t any rock caves just a little hut made out of a coconut shell with smooth rocks around it to keep the snails from moving it. I called my friend and asked him if this was normal and he said no that none of his fry were fighting too much they were just chasing each other around the tank. He suggested I put them in with my mbuna fry but I don’t like that idea because I try to keep separate region fish in different tanks. The younger convict is now hiding between the side of the tank and one of the larger leaves of one of the plants. Is it possible that the convicts are fighting because of being in small numbers? If so, I could get another pair of convicts from my friend and probably some small white cichlids that look exactly like convicts(possibly albino convicts?) which were in the same tank with my convicts. Any suggestions other than having to return one or putting in a divider?

By the way my water parameters are pristine () and I have begun doing daily water changes instead of twice a week. Thanks!
  • #2
Convicts are very aggressive by nature. I'm having trouble following what size tank and who the tank mates are in order to understand what happened in the past.

I highly recommend keeping any pairs in a 20 gallon tank by themselves. Lots of caves/hiding places, plastic plants will help. That should help with some of the aggression you're seeing.

I hope this helps.
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  • #3
Haha sorry. It was written in a hurry. The first paragraph is of my past experience. The second is what is happening now. The convicts I'm asking about at the moment are in a 12g bowfront tank that is heavily planted. Here are some pictures that I just took.

Sorry about the blurry pictures.
  • #4
Do they have a cave? Caves seem to be their favorite place to spawn in.

From the pictures, it looks like you either have two males or your female is really not in the mood, which is a bit unusual for convicts.

Attached is a picture of one of my female convicts showing the spawning colors.

I hope this helps.


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  • #5
At 1/2" they would be completely impossible to sex if you ask me so to say they are a pair doesn't mean much, other than you have 2 of them making a pair of fish. The good news is they will spawn at 1.5" so not much more to go.

Even if you only have two 1/2" cichlids one will be dominant and I would say that is what you are seeing. Your biggest problem is going to be tank size in the long run not matter if you only keep these 2 or get a few more from your friend. I would add some rocks to make some cave areas like already suggested, that should help. Good luck.

Just a note on your previous pair, if they were the same size they were not full grown like mentioned. A male will get up in the 7" range and a female will not get close to that.

  • #6
I agree with Brian, Convects are among the most aggressive cichlids in the world. Pound for pound they will hold their own with any of the heavy hitters of the cichlid would. I owned a male about 15 years ago that was close to 6" total length and a terror. Look at a ruler and see how big a 6" con is, scary for all but the toughest of tank mates.
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  • #7
Oh wow. I didn't know they got that big. My first pair, that I said were fully grown, were probably no more than 2 or 3 inches. Someone told me that they were relatively small cichlids.

The reason I say they are a 'pair', the ones I have now, is because the larger more dominant one has small bits of red on her dorsal fin and the underside of her abdomen which indicates she is a female. And the other that is being terrorized by her has no red at all on its body. That's why I think he is a male. Is it true that overstocking cichlids evens out the aggression a bit?

Thanks for the quick replies!
  • #8
The females stay small- around 3". The males get pretty large 6-8".

Overstocking cichlids only applies to MalawI mbuna from Africa. It won't work on Central Americans, which is where convicts originate. Overstocking with CA's will end in a massacre.

If you are seeing small orange specks on the stomach of one, she'll more than likely end up being female.

These fish would do much better in at least a 20 gallon tank. That will alleviate many of the aggression issues you're seeing in addition to providing caves and hiding places.
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  • #9
Oh okay. I was pretty sure that overstocking only applied to Mbuna cichlids. They seem to be settling down a bit. I saw the little 'male' one out of his little leaf cave in plain sight of the female today. So perhaps this pair will work out. Thanks for the advice! I'll update on them if I see any unusual behavior or if they will let me take a quick video of them .
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  • #10
Well I guess I was wrong. This morning I woke up, after three days of peace, to find the male tail-less and almost dead. And of course the female was swimming around pecking at him every few minutes. So I had to move her to my Mbuna cichlid tank and I stuck my four german/bolivian rams in it. I'm not sure which type of ram they are though. She seems to be doing fine in the Mbuna tank. She tried to bully them a lot at first but found out that she could only slightly bully two of the fourteen. So she has taken to hiding and then coming out to flare at the mbuna. She's getting moved to my heavily planted barb breeding pot in about a week. Maybe she'll leave the barbs alone for a while until she is bigger than them.

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