Jack Dempsey vs. Oscar
- Thread starter kingthedog
- Start date
In nature JDs do well when they are the dominant cichlid in the habitat, if they are not, they often suffer the presence of other cichlids a bit (by that I mean their populations are lower, and they are a bit more torn up.
In comparison to many other cichlids (especially some Central Americans) I don't find either Oscars or JDs particularly high on the aggression scale.
It may seem so, but I believe its because they are often kept in too small enclosures for their true needs.
In the video below, with JDs in nature, they are the dominant cichlid (almost no other cichlids) and they prosper.
Eden2
But below in a different Cenote, where another cichlid (uropthalmus) lives the population of JDs suffers, and they are a bit torn up.
027 zps4b102ffd
In comparison to many other cichlids (especially some Central Americans) I don't find either Oscars or JDs particularly high on the aggression scale.
It may seem so, but I believe its because they are often kept in too small enclosures for their true needs.
In the video below, with JDs in nature, they are the dominant cichlid (almost no other cichlids) and they prosper.
Eden2
But below in a different Cenote, where another cichlid (uropthalmus) lives the population of JDs suffers, and they are a bit torn up.
027 zps4b102ffd
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I don't really know which is the tougher fish, an Oscar or a JD. My guess is it depends on the individual fish. I do know that things didn't end well for my 5 y.o. male JD when his 5 y.o Rivulatus GT tankmate finally got tired of being bullied. The GT totally thrashed the JD before I could grab a net. Both fish were about equal in size, 9 - 10 inches, and had been raised together. RIP, JD.
I would say a big mean oscar will overpower any jd. But most oscars are actually big softies and will cower and run from a mean fish that may even be smaller than them.
JDs are definitely big instigators, but ime are also pretty soft when it comes to actual brawling and will usually be found hiding under rocks when other big cichlids are in the tank.
So it could go either way in my book. Curiously, I've seen this fish combination work for many people. Seems to be pretty common since theyre both so abundant at lfs worldwide.
JDs are definitely big instigators, but ime are also pretty soft when it comes to actual brawling and will usually be found hiding under rocks when other big cichlids are in the tank.
So it could go either way in my book. Curiously, I've seen this fish combination work for many people. Seems to be pretty common since theyre both so abundant at lfs worldwide.
An Oscar, only if he is larger than the Jack Dempsey, if the same size I would say the Jack Dempsey.
A friend of mine tried keeping them together, Oscar killed the JD-- possibly multiples, he tried it more than once before giving it up if I remember correctly. But this was over 40 yrs ago, a different generation of both species, so it may not prove much in that sense, besides the fact that it can depend on the individual fish as mentioned already.
This includes a number of variables, including basic temperament (studies show individual fish within a species can naturally be bolder or more timid), hormonal condition of a fish, whether it's protecting a potential nesting site, etc. Interesting what Duane says about JDs and other cichlids in the wild-- it would tell me their preference would be as the primary species in a tank, or else a large enough and structured enough tank to accommodate their having their own territory-- there's a study out there that found the fish tested were less aggressive in more complex/enriched aquarium settings-- meaning more aquascape and less bare-- 10 points for my side, I've never liked or done bare tanks.
I've observed at least some species not known for aggression can become so in smallish tanks-- based on rescuing 'killer' fish from overly small tanks, putting them in a larger tank and having them be good citizens, besides other observations-- like the discus breeder acquaintence who thought he could make money breeding rotkeil sevs in discus breeder tanks-- back when rotkeils were new to the market and expensive-- and he couldn't understand why all they did was fight.
This includes a number of variables, including basic temperament (studies show individual fish within a species can naturally be bolder or more timid), hormonal condition of a fish, whether it's protecting a potential nesting site, etc. Interesting what Duane says about JDs and other cichlids in the wild-- it would tell me their preference would be as the primary species in a tank, or else a large enough and structured enough tank to accommodate their having their own territory-- there's a study out there that found the fish tested were less aggressive in more complex/enriched aquarium settings-- meaning more aquascape and less bare-- 10 points for my side, I've never liked or done bare tanks.
I've observed at least some species not known for aggression can become so in smallish tanks-- based on rescuing 'killer' fish from overly small tanks, putting them in a larger tank and having them be good citizens, besides other observations-- like the discus breeder acquaintence who thought he could make money breeding rotkeil sevs in discus breeder tanks-- back when rotkeils were new to the market and expensive-- and he couldn't understand why all they did was fight.