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I haven't had aggressive cichlids, only peaceful ones like German Blue Rams. If you get aggressive ones though, they will probably kill other mid level fish like tetras right?

What about plecos, cories, shrimp, snails, loaches and catfish? Can those be mixed with aggressive cichlids? Also can peaceful cichlids be kept with aggressive cichlids?

I'm not planning on getting aggressive cichlids, but just kind of curious to know.

The aggression is usually based on territoriality rather than predatory habits, but a lot of cichids are capable of both.

Its more about having any fish in their personal space especially when breeding rather than any actual concern for the species it happens to be. People lose plecs and loaches, shrimp, and other cichlids to breeding pairs and aggressive species just the same as smaller tetras.

Its not like pure predation when you can house species of comparable size and only the most voracious predators will rip each other apart, or relying on bite size to avoid the consumption of cagemates. If a cichlid feels its territory boundary has been infringed, or its fry and eggs are threatened , or its right over its partner challenged, it may start a campain of liplocking, fin nipping and outright biting until the fish that annoys it , irrelevant of species is either eaten, mutilated enough to die or exhausted to death, and if the cichlid is much more powerful thanthe species its attacking, it will probably kill it outright very quickly.

Having said that, some fish for various unknown reasons slip through the net as it were. Some plecs dont always set cichlids off, my own hyperaggressive blue acaras dont attack silver dollars, doradids amanage to avoid them by being nocturnal in a tank with plenty of cover, and the polypterus seems to be accepted for some unknown reason, but they try to kill anything else on sight. Over a period of weeks they would probably kill a plec People do have cichlids of varying aggression though and the odd specimen will be tolerant , sometimes even pairs are unusually tolerant, but this is not the average. In bigger tanks (and I mean huge!) its possible to give some cichlids enough room so that conflict can be avoided, but when you get to oscar sized fish their natural territorial area is pretty huge, so fighting is sometimes inevitable.

Its probably safer for a beginner with aggressive cichlids to consider that they will attack most things and that when they do tolerate other species is usually more about luck than judgement and to take advice from people who say "Oh my aggressive cichlids live with X species just fine" with a healthily large pinch of salt.

Dont forget, particularly when dealing with people on the net , there are pretenders and armchair theologians who will espouse the possibilities of keeping aggressive species in community without actually ever having done it themselves, and there are a lot of young keen beginners who mistake their juvenile fish's lack of hormonal development as normal behaviour, they are giving out advice that leads to devastation, so approach the whole business very carefully, and a lot of petshops will sell you anything so their advice cannot usually be relied upon either. There are a lot of really quite bad, even abusive cichlid keepers out there, who think nothing of their fish tearing others to bits over weeks,so dont be too willing to take on board their advice. Aggressive cichlids are marked as aggressive for a reason.

When cichlids are being aggressive there isnt necessarily a species they wont attack. In the real world there are no guarantees. Many cichlids are suicidally brave in the defense of their young, and they may attack a much larger fish than themselves, so you cant assume that larger fish will not be attacked, that they will defend themselves or that the cichlid wont be killed in its return attack. a four inch cichlid might attack a 2 foot plec and eventually kill it, or pick on a pacu or arowana, or large predatory catfish and end up ripped in half.

They are like a jack russell terrier attacking an alsation sometimes. They dont seem to have any knowledge of their own limitations .You can reduce aggression with lots of room, visual barriers, and defined territories, but dont bank on it being completely effective. There are no real principles for the avoidance of aggression with large aggressive cichlids that you can truly rely upon, because preferences vary from individual to individual.Deterrant principles often go horribly wrong, and lots of the people that try dither fish just end up having them persecuted and eaten. A lot of fish in the confines of a tank especially tetras and your basic shoalers can be incredibly dumb about keeping clear of nestsites, and they will keep going over and getting beaten to death. In a tank you can never rely on other species having the sense to get out of the way. A lot of malawi and tanganyika communities work because all the fish selected are small, they all have their own nooks and crannies and every fish in there breeds by similar principles and knows the value of not impeding on anothers territory or indeed of leaving their own in case they lose it, so territorial boundaries can sometimes be effectively maintained, but shoalers will fall victim. Its stuff for chancers.

No-one without multiple tanks with which to house incompatible specimens should be attempting series of housing combinations to find out if their cichlids will attack or not.Even then you have to handle it responsibly so that fish abuse does not become a factor. I often have to move fish when breeding starts, because quite simply, if I dont , things will be killed. Its not a situation in which you can dither about or wait, you have to get the victim fish out of there, and if you reliably pre-empt the situation and act before the fighting starts, so much the better.

If you only have one tank, and you keep trying to mix species with aggressive species you'll lose a lot of fish, and an aggressive species put into community may turn a previously happy tank into a charnel house.


Hope that gives you a clear outlook. By and large, don't risk it.

Can't disagree with anything above - leave well alone.

that one was really long so i didn't read it. just to say what i think really quick:

it is gonna be hit and miss no matter what you do. tetra's are not a good choice though. any big cichlids won't kill them, they'l eat them. some things that u could do to better the chances of the non aggressive fish would be to introduce them before the cichlid, get the cichlid when its young so that it can grow up with the other fish, and make sure that the tank is big enough so that the cichlid doesn't feel like its territory is being invaded. it will be almost impossible to introduce a new fish into an adult cichlid's tank that he's already established in.

i've had a lot of luck with pleco's and catfish with american cichlids. but like i said, it just depends on the fish

First question to ask is this.

What fishes share their wild habitat with the Cichlids in question?

The chances are that these fishes are the ones most likely to survive the attentions of the Cichlids.

For example, let's take Mesoamerican Cichlids (Central Americans). Among the fishes that live alongside them in the wild are Belonesox belizanus, a brute of a predatory livebearer that reaches up to 8 inches in length and has vicious teeth lining its jaws, and Astyanax mexicanus, a 6 inch Characin that is both fast enough and tough enough to cope with the Cichlids it shares its home waters with (which includes big ones such as Parachromis managuensis.

Now, in the case of Belonesox belizanus, you'll have the problem of keeping it fed. Because it will only eat live fishes. Which means you'll be breeding guppies like mad to keep it fed, and big ones need half-grown to adult guppies to keep them happy. Astyanax mecicanus is much more likely to be happy with more regular aquarium foods, but it's a shoaling fish, which means you'll need at least 6, and preferably more, and with their level of activity this means a large aquarium. But for many of the Mesoamerican Cichlids you'll be looking at a large aquarium anyway ...

In fact, Astyanax mexicanus, in the wild, is a source of attrition losses among Cichlid offspring. This is because they swarm in shoals of 1,000 or more individuals in their natural habitat, and use sheer force of numbers to overcome parent Cichlids in order to pick off the fry. In smaller numbers they are no real threat, though the big Cichlids will still regard them as such come breeding time, and even outside of the breeding season, Astyanax mexicanus is useful as a dither fish for big Mesoamerican Cichlids because it's tough enough to cope.

Other fishes that can cope with the big Cichlids include the Leporinus Characoids from South America. These grow to be BIG - 12 inches - and so you're looking at a seriously huge aquarium to house these AND the Cichlids. In fact, several Leporinus species are tough enough to pick fights with the Cichlids. Oh, you also have to deal with the fact that Leporinus are infamous for being rocket-propelled jumpers, will destroy plants in an instant, and will pick upon smaller, weaker fishes in a sneaky and insidious fahion.

If you're looking for something that will live with the likes of Firemouths, Convicts or even Salvinis among the smaller Mesoamericans, Buenos Aires Tetras are a good choice, because they too are fast and tough.

In the case of South American Cichlids, much the same provisos apply. You'll be looking at similar classes of fishes to occupy an aquarium containing Oscars, Green Terrors and the like, namely tough, fast swimmers. Although in the case of the South Americans, big Loricariid catfishes are also de rigeur as company, because they share the habitat of many of the big South Americans.

For other bottom feeders, an excellent choice consists of Doradid catfishes. These fishes are very heavily armoured, and in addition are covered in razor-wire like arrays of serrations and spines to deter even the most aggressive of Cichlids. Even catfishes such as a Raphael Cat will not worry unduly about attentions from Convicts or Salvinis because they are, in effect, self-propelled chestnut burrs. Bigger Doradids will fend off unwelcome attentions even from the likes of Guapotes such as Parachromis managuensis. If the idea of a 500 gallon aquarium or more sounds like something you want to populate with big fishes, then some Parachromis dovii and a Megalodoras irwini catfish will probably result in a display that will certainly be eye catching, and you'll never have a dull moment watching them.

When it comes to Rift Lake Cichlids, however, it's a slightly different picture. Most of the extant communities are dominated by Cichlid species, so for a Rift Lake setup, most of your fishes will be Cichlids, with the possible exception of appropriate choices of Synodontis catfishes from the lakes in question. There are other fishes that live in those lakes, but [1] those other fishes are rarely imported, [2] many of them are impractical for anything other than a specialist (and LARGE) setup, and [3] even among those that are imported occasionally and are capable of sharing a home with your Rift Lake Cichlids without requiring outsized aquaria or highly specialised arrangements, the price tags they fetch will probably keep all but the dedicated at bay. For example, there's a Mastacembelid Eel from Lake Tanganyika called Aethiomastacembelus ellipsifer that will live with some Tanganyikan Cichlids, but if you can find one, the price tag will make your wallet wilt and probably cause your bank manager to have a seizure if you buy one!

Mixing fishes from different areas can be performed when choosing companions for large and/or aggressive Cichlids, but it needs to be performed with care. You need to acquire the requisite knowledge as to which species are compatible with respect to water chemistry first of all, then which ones of those are likely to be behaviourally compatible, or alternatively are likely to possess some means of fending off the Cichlids (e.g., those heavily armoured Doradid Catfishes) or are quick enough to escape (Astyanax mexicanus and similar fishes), and then which ones are likely to pose few additional maintenance problems. It's like everything else in the fishkeeping game, namely time spent doing the research before you open your wallet is time well spent, and likely to contribute to [1] increased success when you do perform the stocking, and [2] increased chance of avoiding expensive heartache because the fishes turned out to be incompatible and wholesale warfare broke out.

However, even when you've done your research, spent time analysing the likely compatibility of assorted species, and spent time devising a range of possible alternative stocking scenarios to cope with such factors outside your control as availability and price fluctuations, as LHG stated above, fishes (and Cichlids in particular) are all individual, and you could still wind up unlucky and find that you happen to have bought the mother of all berserker psychopaths among your Cichlids, that sets about exterminating your choices of companions despite your careful research.

So, like everything else in fishkeeping, it's something to approach with your eys open and your brain fully engaged as to the possibilities open.

Hope this helps!


Panda Catfish fan and keeper/breeder since Christmas 2002