Aggressive Green Severum

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Aquarium Advice Apprentice
Jan 10, 2013
Hi all

I have posted a lot about stocking lately. And am having some new issues.

I haven't purchased any fish as of lately, although, I am looking as I know I need some dithers.

For the past 5 years, my blood parrot has been the queen of the tank. Lately, tables have turned. One of my green severums has gotten quite aggressive. I will be rearranging the tank on my next water change, I am just wondering what else to do. It has basically taken over an entire side of the tank.

The tank is a 5ft long 125 gallon. Current inhabitants are:

1 x blood parrot
3 x green severums
2 x bosemani rainbows
2 x rainbow cichlids
1 x bristlenose pleco

I had been advised to add more bosemani rainbow fish for schooling, as well as a larger barb (such as a black ruby barb).

I was hoping the addition of these would help, with the tank rearrange. I was thinking 4 rainbows and 10 ruby barbs. Would that suffice?

Should I add any additional cichlids, I always wanted to get another BP and maybe some convicts.

Looking forward to hearing from you all, thank you!
Adding more rainbowfish is a good idea because they need to be in groups of at least 6 (preferably 10) or more. You don't have to keep just M. boesemani rainbowfish. Any rainbows that grow to the same size will swim and hang out together. So if you want more colour, you could add a couple of Melanotaenia lacustris, M. herbertaxelrodi and something else to make a group of 8-10 fish. The main thing is to make sure they all grow to the same size so none of the bigger males bully the smaller ones.

I wouldn't add any other fish besides increasing the number of rainbowfish. The cichlids get to a reasonable size and the rainbows can reach 4 inches.

Re: the severum. It is probably wanting to breed and has taken over a section, which it now considers its territory and will drive the other fishes away from that area. If you have 3 severums in the tank, there might be a male and female and they might breed. Rearranging their tank could resolve the problem or make it worse. Maybe wait a week and see if they breed. If they don't, then redecorate but expect the fish to set up a new territory somewhere else.
Turns out - the severum was pregnant, arrived home to many babies last night!
Excellent, thank you.

I caught some of the babies and put them in one of the floating safety things for small babies. Is it better to let them out and let the parents take care of them?
Leave the babies with the parents. The parents will look after the young. They might lose a few to other fish in the tank but that is fine and you really don't want 500+ baby severums anyway. If all the babies get eaten, the adults will breed again in about 2 weeks.
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