Any info on Jack Dempsey

No clue on breeding but I have some Jacks and from what I can tell is that they never have faded in colour, they like neutral to slightly acidic water, yes they can hurt each other, they're aggresive but mine have never been aggresive toward other fish (go figure).

JD's breed like most cichlids, lip locking, tail slapping, chasing each other.
Yes then can fade in color, this is brought on by stress, or a show dominace(sp?). The Alpha male will be the Brighest and darkest and the other males will be a washed out lighter color, this happens with alot of cichlids also. They got their name from the Boxer Jack Dempsey and if they live up to his fighting then they can be very agressive, but this will depend on the individual fish, my female is pushed around by convicts half her size. Yes they can hurt each other and they can hurt other fish in the tank. a tank at least 55 gallons(75 would be better b/c its wider) just for a pair. Ph Any where around neutral, the can be acclimated to other ph's with no problem. temp 78-80 any type of substrate, no live plants they will dig them up. Lots of filtration and water changes they are almost as messey as an oscar.

MY jack changes color constantly, when the oscar comes out he fades when the firemouth comes out he intensifies. Most of them I've ever owned were the same in that respect. When I drop anything live in the tank he gets almost black. they like their territories, and can be very defensive. I have never had them get mean with other fish beyond minor territory or feeding disputes. I will say that I've never kept a jack with anything timid either, so how they would act with less aggressive tankmates I don't know. They really like live foods, especially snails, and any kind of live worm, he also goes after my feeder guppies (raised at home not LFS) as aggressively as the Oscar. Mine have never been diggers, but I've never kept pairs either. They aren't quite as messy as Oscars, but close as said. The species profile says they like neutral Ph, I have kept them in Ph as high as 8.0 and not seen any signs of a problem. My tank temp stays between 76-78* and everyone seems happy.
Dave

Jd

Mine are nuts.

The breeding pairs are crazy. The big male I have had for years now is about 9 inches and one mean sob. His current girlfriend is a 6 inch blue dempsey.
These two go at it and beat the crap out of each other. They move just about every rock from one end of the tank to other. They are in a 50 gallon.

The other pair have relaxed a little more. The female goes almost completely black when breeding and guarding the fry. Those two team up and ruin whatever or who ever comes near the nest. Size means NOTHING to those two. That male is about 7 inches and his current grlfriend is the 9 inchers former mate. She is currently about 6 inches. They are in a 45 gallon.

Getting them to breed is easy also. Big water change raise the temp above 80 and then feed frozen bloodworms. Volia! I have a nest within a couple of days.
Rainbow cichlids is almost the same with the only change being frozen brine shrimp instead of bloodworms.

No matter what you keep them with though I highly recommend target fish. BIG fast ones. They will have to be to stay alive. Right now I am using Spanner, Clown and Arulius barbs. They help keep the JD's mating wounds to a minimum ( they tend to seed up the process when other fish are around) and gives the female time to rest when the male decides to take out his pent-up-anger on the targets.

i bought a JD pair and withing a few weeks they had babies. I have had them for 2or 3 months now and they have breed twice.