About the Jack Dempsey
Species Type: Freshwater Fish
Care Level: Moderate. May tolerate only a narrow range of water parameters, have specific dietary requirements including frozen or even live foods, may have behaviors that severely limit potential tankmates or may require a specialized aquarium setup.
Origin: 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.
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 otofasciatus. In 1980 and thereafter, ichthyologists considered the species to be in the genus Cichlasoma with the species epithet changed to otofasciatum 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 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).
Nelson, Joseph S., E.J. Crossman, H. Espinosa Pérez, 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.
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.