What fish will you NEVER EVER keep with cichlids?

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Fanatic_Fish_Lunatic

Plecostomus
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Jul 24, 2024
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Hi! What fish do you guys consider MUST NOT be kept with medium and large sized cichlids(such as Jack Dempsey, Peacock Bass, Oscar, Jaguar and Dovii as examples) at all costs, not because aggression, but because they 100% will and are going to eat your cichlids, guaranteed. Especially those that I've seen being kept with cichlids many times such as RTC, Tiger Shovelnose, Large catfish that grew over 1 metres, alligator gars, arapaima and many more.
 
Piranhas (or any of the larger predatory characins)
Eventually there will be fighting and the cichlid will either kill the piranhas or die trying. Also anything that’s in a tank with a p is eventually its meal.
 
Piranhas (or any of the larger predatory characins)
Eventually there will be fighting and the cichlid will either kill the piranhas or die trying. Also anything that’s in a tank with a p is eventually its meal.
I think piranhas could work, but extremely hard. I'm not talking about the likes of Rhom, but schooling piranhas. If you put just 1-3 of them(not the amount that they can be cocky since they're small) in a large tank that has many larger predatory fish, by many, I meant MANY. Just enough that piranhas(that already has extremely small school) can't focus or target any other fish. Also always keep them well-fed. It's either works or fails. 50/50, I'd say. I'll probably never try them myself, cuz they're illegal in my country, but illegal or not isn't a problem for me, but they're hella expensive so I won't buy them. 2 small piranhas in my country are as expensive as a juvenile arapaima.
 
Piranhas (or any of the larger predatory characins)
Eventually there will be fighting and the cichlid will either kill the piranhas or die trying. Also anything that’s in a tank with a p is eventually its meal.
I think piranhas could work, but extremely hard. I'm not talking about the likes of Rhom, but schooling piranhas. If you put just 1-3 of them(not the amount that they can be cocky since they're small) in a large tank that has many larger predatory fish, by many, I meant MANY. Just enough that piranhas(that already has extremely small school) can't focus or target any other fish. Also always keep them well-fed. It's either works or fails. 50/50, I'd say. I'll probably never try them myself, cuz they're illegal in my country, but illegal or not isn't a problem for me, but they're hella expensive so I won't buy them. 2 small piranhas in my country are as expensive as a juvenile
Piranhas (or any of the larger predatory characins)
Eventually there will be fighting and the cichlid will either kill the piranhas or die trying. Also anything that’s in a tank with a p is eventually its meal.
My current stock are an oscar(8 inches) raised since he/she was 2-3 inches, a striped raphael catfish(5 inches), a black ghost knife fish(10+ inches), a salminus affinis(4-5 inches), an armatus payara(5 inches), a hoplias malabaricus(6 inches), a motoro stingray(7 inches), a silver arowana(7-8 inches) and a monoculus peacock bass(7 inches). All have been doing well together for past 6 months. All of them never fight, the most aggressive one is the salminus affinis though.
 
To me cichlids such as Oscars and Cichla, from soft, low pH, (7 or lower) waters of S America, should never be kept with
any Parachromis, or JDs from the hard, high pH (8 or even above) of Central/North America,
much less the obvious catfish, or predatory Characins that also require different water parameters.
If the tap water is one way or the other, one of the continental versions will get short changes health wise.
 
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Even within continents, just because cichlids are cichlids, doesn't mean they prefer the same habitat.
Heros species from the calmer sedate waters in Amazonia, prefer radically different biotopes that some rheophillic Geophine species, and are seldom found in the same habitat, and if by chance they do find themselves together one or the other gets short changed.
Parachomis dovii found in clear waters of Nicaragua and Costa Rice are seldom found in the more burbid water Panachromis managuense gravitate to.
And then there are the geographis barriers that have separate species, and created the myriad of species we know.
JDs from in the Yucatan will never meet Parachromis dovii from Costa Rica, and if the did, the dovii would probably eat the smaller JDs.
In nature dovii commonly eat conspecifics if the venture into a in-opportune spot....

Below some research

In the wild, the Wolf Cichlid (Parachromis dovii) is an opportunistic, carnivorous predator that eats other cichlids, including their own kind, along with insects and other small fishes like tetras and guppies, especially during their juvenile stages. It hunts by stalking and ambushing smaller animals that fit into its powerful jaws.
 
Even within continents, just because cichlids are cichlids, doesn't mean they prefer the same habitat.
Heros species from the calmer sedate waters in Amazonia, prefer radically different biotopes that some rheophillic Geophine species, and are seldom found in the same habitat, and if by chance they do find themselves together one or the other gets short changed.
Parachomis dovii found in clear waters of Nicaragua and Costa Rice are seldom found in the more burbid water Panachromis managuense gravitate to.
And then there are the geographis barriers that have separate species, and created the myriad of species we know.
JDs from in the Yucatan will never meet Parachromis dovii from Costa Rica, and if the did, the dovii would probably eat the smaller JDs.
In nature dovii commonly eat conspecifics if the venture into a in-opportune spot....

Below some research

In the wild, the Wolf Cichlid (Parachromis dovii) is an opportunistic, carnivorous predator that eats other cichlids, including their own kind, along with insects and other small fishes like tetras and guppies, especially during their juvenile stages. It hunts by stalking and ambushing smaller animals that fit into its powerful jaws.
I remember that you're very strict about keeping fish uh, what is the word again? But anyways, I'm not strict about keeping fish from different places together, but for real though, I don't know what those videos on YouTube were talking about when they said alligator gars, arapaima and RTC can be kept with oscars. How did people even believe that? 2-3 metres fish with 30-40cm fish. I won't keep my cichlids with something that could eat them easily.
 
I think piranhas could work, but extremely hard. I'm not talking about the likes of Rhom, but schooling piranhas. If you put just 1-3 of them(not the amount that they can be cocky since they're small) in a large tank that has many larger predatory fish, by many, I meant MANY. Just enough that piranhas(that already has extremely small school) can't focus or target any other fish. Also always keep them well-fed. It's either works or fails. 50/50, I'd say. I'll probably never try them myself, cuz they're illegal in my country, but illegal or not isn't a problem for me, but they're hella expensive so I won't buy them. 2 small piranhas in my country are as expensive as a juvenile arapaima.
1 piranha has the same prey drive as a shoal. I’m talking from experience where I attempted cohabbing my red with a Texas cichlid. The Texas tried to lip lock the piranha and you can probably guess what happened there - a week later I found half of the fish swimming around. The same p also took a chunk out of a leporinus’s face (the one in my profile pic).
It’s not just about size, but behavior and weaponry. I’d sooner trust a natural scavenger like a rtc with an Oscar than a pygo. I can’t say I’d trust the rtc either, but it’s less likely to prey on it imo.
FWIW I wouldn’t trust the wolf or payara with your fish either long term. I know it’s a somewhat common cohab but they are just very violent fish. Even if it won’t eat them, it can seriously injure your other stock.
 
I actually don't think I am strict about keeping fish, but.....
because I was a microbiologist, I am aware, that a fish evolved to live in the pH 5, soft and low mineral content, tannin stained waters of the Orinoco, such as Colombian oscars or Cichla , will not be immune or equip to resist the infective bacteria that inhabit the pH 8.2, annd hard waters of the Mamoni river in Panama.
The cichlids are not all that overtly sensitive, but bacteria are.
All you need do, is check the disease section and see all the queries about "mysterious maladies" , or are scarred up with HITH just as they hit 2 years or age, that arise when cichlids such as oscars are forced to live in water they have not evolved or resist infections in, and vice versa.
 
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At the end of the day, the species that are going to be best suited for living with a particular species are the species that already do exist with it in nature.
It's not so much a matter of being strict, as it is being realistic with what is best for a stable fish-tank in the long run.
There are many fishes that care far less in regards to water, or tank-mates- but in the same vein there are many that do.
As Duane said, the water-chemistry matters a lot with many species, and not following it can lead to complications down the line.
Like altums, and wild discus, that are adamant about soft water with almost no TDS or conductivity. They are no less a cichlid than a Haplochromine from Lake Malawi.
On top of that, a fish-tank is highly unnatural, and brings out odd behaviours in fish; viewing how they act in situ makes it all the more clear.
For instance, a lot of Crenicichla (especially larger spp.; saxatilis-group/Saxatilia, lugubris-group/Lugubria) are seemingly rather passive in the wild, and oftentimes form large shoals.
In captivity, they are regarded as fiercely aggressive and highly territorial to the point of being intolerant of other tank-mates, because the given space they are forced to inhabit is substantially limited.
I think the question is too broad to be able to answer it well- after all, there are answers that apply to all fish, such as any fish that is excessively territorial/aggressive, a fish big enough to eat the cichlid, a fish that will be harassed to death or killed/eaten, etc.
You did elaborate on wanting to know of fish that would be able to eat a large cichlid... but to me that would be almost any larger predatory fish; and you did sort of answer your own question by pointing out the obvious mainstream examples- there aren't too many others that are going to be found that an aquarist would keep with an aggressive Parachromis/Andinoacara/Cichla because they would know better than to do that, if they seek out such species (like many of the predatory Asian cyprinids, Lake Tanganyikan Lates spp, larger Silurus spp., etc)
I myself prefer to keep cichlids either in a species-only setup, or as a 'biotope'-type setup with other species from similar/same waters.
Then again I mostly do this because I prefer keeping smaller Geophagini and 'dwarf' West Africans, that are more sensitive and particular about their water and tank-mates.
 
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