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Main Index > Detailed Fish Profiles > The Cichlids > Jack Dempsey
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This page will give a completely detailed profile of the selected fish, from A to Z. The profiled fish will be chosen randomly by Badman, and will come from the complete genre of tropical fish. New profiles are added on a regular basis. If you would like to submit a profile for the site please contact me. Don't forget to let us know you experiences with this fish by filling out the

central america


Jack dempsey

Rocio octofasciata
(Cichlasoma octofasciatum)


    One of the all time favorite aquarium fish. The Jack has been around for many years and seems to take the "test of time" very well. Pugnacious and intolerant of other fish, they are best suited for a species tank.

Quick stats:

    Listed tank sizes are the minimum
    Size: 10 inches  (25.0 cm)
    Tank: 48 inches, larger for adults
    Strata: Bottom, middle
    PH: 7 to 8.5
    Hardness: Medium hard to very hard
    Temperature: 77° to 82°F  (22 to 30°C)


    Order: Perciformes
    Suborder: Percoidei
    Family: Chiclidae
    Genera: Cichlasoma


Common name:

    Jack Dempsey

Image gallery:
    Additional species photographs


    Badmans' Forum


    Central America, Honduras, Guatemala and the Yucatan.

General Body Form:
    Somewhat elongated with lateral compression. In the males the Dorsal and Anal fins are pointed and can reach a length to the middle of the Caudal fin. In the females they are shorter and more rounded. The Caudal fin is fan shaped. In older males the forehead swells to a telltale bump.

    The male "Jack" base color is a dark Brown to Gray Brown, which when spawning or in top condition becomes dark Blue or Blue Black. On the scales on the sides there is a beautiful shinning Blue or Blue Green dot. The young have a series of seven or eight faint up and down bars that usually disappear in adults unless they are stressed or excited. A long Black Longitudinal band runs from the rear edge of the gill covers to a large Yellow edged Black spot in the middle of the side. There is also a similar spot at the start of the Caudal fin. The cheeks and gill covers themselves are covered with Blue dots and the lips are a pale Blue. The Dorsal fin is dark and has a thin Red border. The females are paler in color and the Blue is not as intense.
Electric Blue dempsey
The new Electric Blue variety

    Typical to most Cichlids the "Jack" is a Hardy and easy to care for fish. They will accept all types of food and relish anything live. The tank should have plenty of caves and nooks to hide in with driftwood and rockwork. Jacks like to dig so use artificial plants or Java Fern anchored on the driftwood. Provide good filtration and do frequent water changes, they are very temperature tolerant and can even live in water temperatures in the Sixties.


    Slow moving stretches of water in Central America.


jack with fry
Courtesy of Shari, from the message board


    A typical open breeder which can spawn in large pits dug by the parents. They will dig vigorously during spawning so be prepared. The substrate should consist of fine gravel or sand. Provide a layer of floating plants if desired. They are very prolific and a pair that has spawned together usually will do so again and again. They are excellent parents and will provide intense brood protection. The spawns can be quite large and the eggs can number in the high hundreds. For more info on open breeders please visit the breeding info page.


Your comments:


Please remember that the following comments are personal experiences and may or may not apply to your setup. Use them as guide to help better understand your fish, like us all individuals will behave differently under different circumstances.


From: Sivadffej
Electric blues are not the same as a regular jack dempsey. They are not as aggressive and don't grow as fast. I've had mine as long as my regular jack and he has only gotten a half inch tops in 6 months. He is although as out going and will stand up for himself against a fish his size! oh ya he is 2 inches and i have him in with tetras, an anglefish and a brichardi
From: Mike
Jacks can go both ways. Some can be extremely aggressive and others can be housed in a community tank with larger barbs, tetras ect.. This is what makes the Jack Dempsey such an interesting fish. Each one has its own unique personality. It is true that females tend to be less trouble than males. So if you can tell them apart, it would make sense to put a female into a community tank setting and a male into a single species only tank of other male cichlids. As far as tank size goes, a minimum tank size for one full grow Jack would be 30 gallons. Anything less would be problematic.
From: Mike
I keep seeing posting on here with people upset that a jack ate your tiger barbs, your guppies, your loaches etc. Come on people!if you put a fox in the henhouse the chickens will get eaten!jacks are large aggressive fish and should only be kept with similar tempered fish. I've had jacks for about 10 years now and have enjoyed them very much. right now I have a large 10-12 inch male who is living quite comfortably with a 12-14 inch oscar and a 8 inch red terror. Here are a few tips to keep all of your fish happy ,
  • 1 rearrange the rocks every couple of weeks to keep them from establishing territories.
  • 2 keep them well fed a hungry dempsey can be mean.
  • 3 keep the water quality good a sick dempsey can also wreak havoc.
  • 4 keep them with the proper tankmates in an appropriate sized aquarium. tank mates should be of similar size and also be aggressive south American cichlids.
  • 5 when spawning move to a separate tank. That should keep them from killing others when defending their young.
I hope this can help a few hobbiests and give the dempsey the good naame it deserves
From: Cheeseinacan
A stunningly beautiful fish. Contrary to almost every other experience I've heard, my Jacks arenít very aggressive at all. Sure, the 8 inch male is the nastiest fish we have in the tank, but in a 75 gal. community tank, thatís not saying much. The only thing that rivals his clout is a 9 inch Leporinus but the rest include the 6 and 4 inch females, a group of blackskirt and Congo tetras, tiger barbs, silver dollars, various Gourami, a pinktailed chalceus and a pleco. We havenít had a single death in at least 9 months, and that was a Cory that died of old age (had to be at least 6 or so). By no means am I suggesting that you should introduce your Jack to a community tank, though--I think the reason why my Jacks havenít turned my tank to a bloodbath is because I raised them from the time when they were about an inch long in that community tank, I donít introduce anything thatís small enough to swallow and the I keep the fish very well fed.
From: Jennifer
This is horrid!!! When you go to purchase a pet do you people not ever read before you buy? Jack Dempsey, Oscars, and other cichlids are aggressive fish! If you were to buy a Pit Bull Dog as a pet you know that they are aggressive dogs by nature, and you would more than likely make the proper arrangement for this kind of dog. It should be the same with fish of any kind. Jacks and Oscars are large fish and need adequate space to live. A 50 gal. tank MINIMUM is required for ONE fish. There is a "turf fight" when there is not enough space which causes unnecessary deaths of other fish. Not to mention that some of the tank mates you are picking out because they are pretty are not good tank mates and you are only setting yourself up for trouble. I am sorry if I seem a little upset about this but fish are a passion to me. I am appalled at the lack of information that most pet stores give for raising healthy fish. Please do our fish friends a favor and do your research before you buy. Don't read just one book either, read several and read articles, and search the Internet. Make a wise decision. You will feel better about yourself if you do.





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