Electric Blue JDs usually don’t get much bigger than 3-4”, so they don’t need a huge tank. Can’t guarantee they’ll remain compatible when they’re adult, because they’re cichlids, but they’re a lot more ‘mild mannered’ than regular JDs.
The bottom like with Jack Dempseys is to look up the real person of that name. A boxer. Guess why they got that name when they came into the hobby?
Whatever process created the electric blue morph, they are not as rough and rowdy as the real Dempsey, as @Ichthys just posted as I was writing this! They're a bit more peaceful, but if you get two males, all bets are off.
Buying them, and jewel Cichlids are 2 of the most destructive beginner purchasing errors out there, along with red tailed and rainbow sharks. I don't know why so many stores push these fish at newcomers, because their violence can be terribly discouraging.
I wrote this profile for another site, it willprovide information.
Family: Chiclidae, Subfamily Cichlinae
Common Name: Jack Dempsey
Origin and Habitat: Atlantic slope of southern Mexico down to Honduras; introduced into several other countries. Inhabits lowland waters such as slow-flowing rivers and streams, ponds, swamps, ditches and canals having substrates of mud or sand. Prefers murky water or water thick with vegetation.
Compatibility/Temperament: Not a community fish. Best kept individually, or may be kept in a small group of 6 or more in a very large tank. Should not be kept in smaller groups due to their aggressiveness. As the fish matures it becomes increasing more territorially aggressive.
Jack Dempsey Diet
Naturally feed on worms, crustaceans, insects and fish. Will accept any prepared foods. Should be fed a variety of foods to maintain good colouration and health; include some live brine shrimp, bloodworms and smaller earthworms as "treats."
May attain 10 inches, though 8 inches in aquaria is normal.
Minimum Tank Suggestion
48 inches in length, 50 gallons and larger.
Ideal water parameters for Jack Dempsey
Medium hard (9-20 dGH), basic (pH 7-8), temperature 22-30C/72-86F. Preferred temperature in aquaria is 22-25C/72-77F.
The common name refers to the 1920's heavyweight boxing champion, and was initially applied to the fish because of its aggressive nature and "facial resemblance." Although more recent cichlid fishes to the hobby are sometimes more aggressive, this species still deserves its name.
As mentioned under Compatibility/Temperament, this fish is best kept as an individual in a 4-foot tank. A substrate of coarse sand or very fine gravel will allow for the fish's burrowing tendency. Rock boulders (river rock) and bogwood can be used. Substrate plants will not be feasible, so Java Fern and Anubias attached to rock or wood will provide some planting; floating plants should always be included, since this fish only occurs in overgrown, dim waters. The fish can live for 10-15 years.
The male Jack Dempsey is usually dark brown to gray brown in color, and when it spawns it becomes a blueish shade. On most of their scales, they have beautiful shiny green or blue dots. A long black band runs from the rear of the gills to a large yellow spot on its side. The dorsal and anal fins are pointed and can reach to the Caudal fin. Older males often have a small bump on the forehead. The females are usually smaller and not as colorful, with shorter dorsal and anal fins; the dorsal fin is dark with a red border. All Jacks have different personalities, and can change colors very fast when excited, scared or threatened.
This cichlid is a substrate spawner, using depressions or pits. Parental care is thorough, and pairs will repeat spawn. Hundreds of eggs can be laid at each spawning.
C.T. Regan described this species in 1903, naming it Heros octofasciatus. The species epithet is derived fro the Latin octo [=eight] and fascia [=banded]. In 1980 and thereafter, ichthyologists considered the species to be in the genus Cichlasoma with the species epithet changed to octofasciatum to agree with the gender of the genus name. Nelson et al. (2004) considered this placement to be incertae sedis [uncertain] and R.R. Miller (2006) moved it into the genus Archocentrus (as A. octofasciatus) but the following year Schmitter-Soto (2007) established this as the type species for his newly-erected genus Rocio; there are presently two additional and very similar species in the genus, R. gemmata (native to the Yucatan Peninsula, Mexico) and R. ocotal (endemic to Lake Ocotal in Mexico). The genus was named after the describer's wife; the Spanish word means morning dew, an allusion to the resplendent spots on the cheek and sides of some species, especially R. gemmata.
Nelson, Joseph S., E.J. Crossman, H. Espinosa Perez, L.T. Findley, C.R. Gilbert, R.N. Lea and J.D. Williams ( 2004), Common and scientific names of fishes from the United States, Canada, and Mexico. Sixth Edition. American Fisheries Society, Special Publication 29.
Schmitter-Soto, J.J. (2007), "A systematic revision of the genus Archocentrus (Perciformes: Cichlidae), with the description of two new genera and six new species," Zootaxa No. 1603, pp. 1-76.
I used to have an electric blue jack Dempsey in my large cichlid tank and he passed away quite shortly. I was not sure why as he was eating well, water parameters all well, no one was bothering him, but I found out that a lot of the electric blue jack dempsys do not survive to adult hood compared to normal jack Dempseys because of how they have been artificially bred. Sorry to say, but I think in the longer run it is better to return them. I agree also with what everyone has said and would say typically the sharks are quite aggressive at the bottom of the tank. I was also not told this and my cichlids ended up bullying the rainbow shark as they were bigger than him so I had to return him.
Sorry guys I moved house, this was a good read thank you. I got in touch with the pet shop but they wouldn't take the jacks back, my friend had a spare tank for me to lend until I can purchase a bigger one for these guys. I know its not ideal at all but they are now in a 65litre tank just them with live plants and rocks until I can purchase a bigger tank for them. Since moving the fish over and getting a better look at them the smallest jack has only one flipper I always thought it swam a bit tilted but put it down to it been sooo skinny now I know why it swims like it does with only one flipper and it already had pop eye in one eye when I bought it. So I am treating the tank with aquarium salt and raised temp to 83f but not seen any improvement it is now my 3rd week and noticed the smallest jack has white spot. I checked my water my ph is 7.5 ammonia 0 but my nitrite is a bit pink in colour so been doing more water changes but isn't going down. I have added more live plants to help with this. Then yesterday I looked and the bigger jack has one eye filled with blood so don't know if its nocked the eye on wood or rocks. I do not know what els to do any help would be great.