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how big of a tank do they need

38 gallon bare minimum (yes has to be 38 because of its dimensions), after that you are looking at a 55 which will be more comfortable for it and you could probably even have a catfish such as the larger species of bumblebee catfish in with it. 75 gallon would be the best though, then you could have a few tank mates.

keep in mind that these are large cichlids and require a good work schedual to keep water clean.

I would go with the 75 for sure. You could always go with a 55 but do you really want to have only 1 fish in the tank? If you go with a 75 you could have a pair of JDs or a JD and some smaller cichlids such as Convicts or Firemouths.

Adult Dempseys are 8 inch fishes. Some sources claim that males can reach up to 10 inches. Plus, they possess a very strong territorial instinct - in fact, among the CA/SA Cichlids, it has one of the strongest territorial instincts of the lot, barring the likes of Black Belts and Guapotes. It will make large demands on territory, and deal swiftly and ruthlessly with anything considered to be an 'intruder' in that territory. Which is why big aquaria are the way to go with Dempseys, because in a small aquarium, a Dempsey will effectively claim the whole aquarium as its exclusive domain. Which will make it impossible to keep anything else alongside a Dempsey in anything smaller than a 75. The situation becomes even more acute if you have a breeding pair: once they have eggs and fry to look after, the red mist descends in a BIG way. There's several other recent threads here in the Cichlid section of the Forums on Dempseys, inclunding some reported personal experiences that will prove to be an eye opener.

This fish isn't named after the 1920s World Heavyweight Champion for nothing - if you check out the history of the boxer in question, he was the Mike Tyson of his day, a man who instilled abject terror in many oppponents in the ring. The fish is well named after him because, like the boxer, it doesn't take prisoners.

If I was thinking of taking on Dempseys, I'd be thinking of a 125 gallon. Even in that space, Dempseys can cut up rough if they are in the mood, and need tough companions.


Panda Catfish fan and keeper/breeder since Christmas 2002

Yes the bigger the tank the better JD's are. But i think one can be happy in a 55 gallon tank. If you have cover a tankmate or 2 can be in there fine.

and yes ther are probably rarities of bigger fish. look at asians who average like 5'5"-5'8" then there is Yao Ming, 7'6"

Mos def on the size of Jacks. Today at one of the LFS' I saw one that was 12" and just a massive robust specimen. He made the 10" oscars he was in with look small. He was a beautiful fish, hope mines grows up to be this impressive.

By all means marry; if you get a good wife, you'll be happy. If you get a bad one, you'll become a philosopher.
Socrates-
I happen to have become a philosopher

the jack i have at the moment is only about 7 inches long and he is a nasty fish,it was really weird he lived with all my other sa chiclids for ages then like over nite he chopped into my blue acaras,my green sevrums,dug up my gravel ripped up my plants,hes colours just glowed and he just went crazy,the only fish he couldnt beat up was my male salvini,and thats only cause the jd cant fit in where the salvini lives,so anyway,even a huge tank in the end for some of these guys just wont do,untill yesterday mine was in a 200gal!,and i still eventuly ran into territory problems,and keep in mind how fast these guys grow,i added my jd last to my 200gal and he was the smallest fish and he over took them all,very nice but very nasty,good to have a spare tank or divider on hand to combat unexpected aggresion.

Sounds like you've got a male with a sudden testosterone rush there ... and when that happens with a Dempsey, fireworks ensue!

If you're having problems with a Dempsey cutting up rough in an aquarium as large as two hundred gallons, then this should be ample warning to anyone else out there that a Dempsey can be a MEAN fish when it wants to be.

Oh, and yes, the colours do glow SPECTACULARLY when a Dempsey is in breeding mode - which sounds a LOT like the situation you're in. Big male on the lookout for a female to mate with, and frustrated like mad because he can't find one. Does your fish have really long flowing tips to the dorsal and anal fins? If it does, chances are it's a male. Time to get that bad boy a girlfriend to keep his mind off wanton destruction and mayhem


Panda Catfish fan and keeper/breeder since Christmas 2002

yeah he is a male for sure,the only other fish that ive seen go mental like that is my male flowerhorn(jaws)and he had the same problem,just needed a woman.so im currently looking for a girl for my jack,hes in a smaller tank for now so hes got the poos.i cant wait to breed them this will be a first for me,i never spawned jds b4.i rekon he would have to be my second tuffest chiclid now and he is no where near the biggest,but i bet he could beat em all up,man is he cranky at the moment.anyway seeyas

If you're introducing a female to him for the first time, use a divider. Something made of a heavy, durable plastic with holes in. That way, the two fishes can accustom themselves to each other and learn that they're the opposite sex without coming to blows first time. With fishes as tough as Dempseys, you'll need a sturdy divider.

Once you see the fishes displaying to each other without trying to attack each other through the divider, then try a test removal of the divider. Demspey courtship looks like all-in wrestling to the uninitiated - they lock jaws and engage in a tug of war. There's a nice illustration of a mated pair of Dempseys doing just that in the old Innes book.

Provide flat rocks on the bottom for the fishes to spawn on. once you see them both cleaning a rock, a spawn is imminent. They'll spend hours doing this at first, and they'll circle their chosen rock like hunter killer submarines daring any intruders to cross the line, as it were. Which, by the way, will include your hands during maintenance!

A big pair of Dempseys can produce a lot of spawn. 2,000 eggs isnt unusual for them.

A good apir of Dempseys make superb parents. You'll be astonished how gentle these bruisers can be with their fry, in comparison to the brutality they can unleash upon intruding fishes!

A trick from the old Innes book that works well with big Cichlids spawning is to give them something that acts as a focus for their defensive instincts. Dragonfly larvae serve two purposes here - the Dempseys attack them as threats to the eggs and fry (and Dragonfly larvae ARE a threat to fry), and simultaneously receive a nice nutritious crunchy treat that they demolish in short order. Some water beetles will also serve the same purpose. Choose your prey insects carefully - smaller sized water beetles will be attacked by an average sized pair of fishes, but avoid putting in the big, striped Great Diving Beetle (Genus Dysticus) unless your parents are big - ideally over 8 inches long. A big Diving Beetle from that Genus is capable of latching onto the gills of a smaller fish and feeding vampire style off the fishes' blood, so only use those with really big Cichlids. Giving your Cichlids an outlet for their defensive aggression when spawning will also help strengthen the pair bond, and works well with tough, aggressive species like Dempseys - this is the kind of thing they do in the wild.


Panda Catfish fan and keeper/breeder since Christmas 2002

well thats what i call some helpfull info,it sounds like the procedure i used to get my flowerhorn male to spawn,ive already got a tuff seethroo divider with plenty of holes in it,and i ordered two females from my lfs this morning,they will be here next week sometime.so now all i need is to get them to hook up,they will have there own tank,the filtration is strong,the water is well aged,nice and clean, regularly changed,ive been feeding him all sorts of pellets and live foods,when i get the femalecan you think of anything else that i can do to help them hook up and spawn.

Partly it's a matter of luck. When trying to pair off two adult Cichlids, you have to be prepared for your matchmaking efforts to fail, because either of the partners doesn't like the other. Worse still, they could show signs of being eminently compatible and ready to mate, only for something to throw a spanner in the works, and hey presto, your would-be parents are engaged in a lovers' tiff, so to speak ... only with Dempseys these feuds are not pretty to watch.

Usually, the advice is to pick a female that's of comparable size to the male when pairing adults the hard way, partly to give the female a fighting chance if the male rejects her and turns violent. However, as the venerable Innes book observes, it's amazing how often an apparently hopelessly mismatched pair (one partner twice the size of the other!) turn out to be excellent parents and devotedly monogamous ...

Bascially, never underestimate their intelligence and their capacity to leave you dumbfounded, and you won't go far wrong. Embark upon the enterprise expecting them to be wilful and ornery just for the sheer fun of rubbing you up the wrong way, then be pleasantly surprised when it all goes right. That way you won't be caught on the hop.


Panda Catfish fan and keeper/breeder since Christmas 2002

yeah any chiclids that i get for the perpose of breeding i try to get like ten and let lem go and pair up them self,ive been lucky and unlucky b4,but your rite match making can be a challenge,especaily when dealing with a mental case like my male,but thats half the fun to me,and the fact that ive never spawned jds,do u think ive increased my chances by getting him to females to choose from.i think it will be ok,when he was in my 200gal,i think he fancyed my female blue acara,but she has a partner so he dipped out.if it turns out that he dosent like the 2 females im getting him,do u think i should keep trying to find him a partnerbecause now that hes getting big and hes getting a personality,and he thinks he is just to coolive become attached to him so im not getting rid of him.he can be so cheeky.

Now that I can speak from personal experience, Jack Dempseys are the bomb.
They're totally worth it, pretty much regardless.
Buy them a nice big tank and heavy filtration. It's not how little can they survive with, but how can I give these beautiful, intelligent, amazing fish the best possible life?
:-D
I *heart* them dearly

well ive gotta go to my lfs store tomorrow so i hope the 2 females i ordered are in,my jack will be happythe poor dude he wants a woman BAAAAD.ive also heard that they move there fry around alot,to pits dug around the site,is this truedoes anyone know.

Oh yes, once the fry have hatched, Dempseys will move them about a lot until they're free swimming and can be herded. This behaviour is basically their way of keeping fry thieves confused as to the whereabouts of the babies.

What will happen is this. One parent will stand guard over the fry while the other digs a new pit. The one standing guard will load a clutch of fry into the mouth, and the two fishes, in accordance with a pre-arranged signal, will suddenly dash across the open water, exchanging places. Then, the parent that was over the new pit will grab a clutch of fry, and swap places with the one that's just carried a batch over. This will continue until all the fry have been transferred. It's fun to watch.

It does, however, mean that your Dempseys, when you have a mated pair and they're breeding, will dig gravel. They will be underwater bulldozers on a truly scary scale. Abandon all hope of preserving your decor in a Dempsey breeding tank, because they'll rearrange it to suit themselves. Unless you've cemented your rocks and bogwood to heavy slate bases and buried the slate.

Gravel digging will DEFINITELY take place, and on an industrial scale. A pair of Dempseys in parental mode are capable of shifting the entire gravel bed to one side of the aquarium in about 3 to 4 hours if they're so minded, and I'm talking here about a LARGE gravel bed in a spacious aquarium - these fishes can shift up to 100 pounds of gravel per hour! While they lack the sheer brute physical strength of a big Guapote upon account of smaller size, they make up for it in determination to get the job done.

One thing, you can never say that big Cichlids lack personality.


Panda Catfish fan and keeper/breeder since Christmas 2002

well i sort i figured that they would move decore aroundthe tank that my male is waiting in for his girl in,has a nice thick layer of gravel,i took all the decore out except a flat rock and this castle thing to hide in, apart from that its empty,ive added exrta filtration too for when they do start bulldozing the gravel.when its all said and done i would like to add the pair of jds(if it happens)to my 200gal,but from what you have told me these guys are terminatorsat spawning time and i dont want my other fish to get killed,but i dont want to let the jacks get use to having there own tank,i fell into that trap b4,and it can be murder trying to reintorduce a fish that use to its own tank.how do u think ill go.

Divider time again. Put the Dempseys in one part of the bigger aquarium, and keep them segregated from the other fishes. Then, if they show signs of being compatible, experimentally remove the divider, being mindful of course of the need to reintroduce it if warfare DOES break out.

Strictly speaking, in a 200 gallon setup, there should be space for everyone to get along outside of breeding time, but of course once the Dempseys start spawning, the red mist descends big time.

As for not letting them get used to their own exclusive setup, sometimes they force this upon you. One of those aspects of keeping big, bad Cichlids that you have to live with.

Panda Catfish fan and keeper/breeder since Christmas 2002

well sounds like a challenge is install for mebut no matter what im keeping my jd now,and my lfs store says 2morrow for my 2 female jds,and the male is already digging himself out a homeas for tring to reintroduce them after spawning if my efforts fail what size tank do you think the pair would be happy in and reach full size

If the Dempseys end up demanding a home of their own, well I suspect you coul get away with just the two of them in a 75 ... they might not grow to quite full size in that setup but they'd have reasonable space. If your budget will run to a 125 of course, then you'd be sorted.

Your house is going to be a tad cramped with all those big Cichlid tanks.


Panda Catfish fan and keeper/breeder since Christmas 2002