双点丽体鱼 · Jack Dempsey Cichlid

Overview

Rocio octofasciata, widely known as the Jack Dempsey cichlid, needs planning around adult size and pair behavior. Juveniles can coexist, but conspecific aggression often increases at maturity. Relative tolerance within a pair does not establish peaceful behavior toward other fish.

Distribution & habitat

It is native to Atlantic-draining Central American waters in Mexico, Belize, Guatemala and Honduras, from the Veracruz region to western Honduras. Established populations in countries including the United States, Russia, Australia and Thailand are introduced. Coastal drainages and slow lower river reaches are frequent habitats, but channels, canals, ditches, lakes and ponds are also used.

Aquarium setup

An adult pair needs at least approximately 120 × 45 cm of floor space, with much more room for other cichlids. Soft sand is preferable, together with one or two flat rounded stones as possible spawning surfaces. Wood, roots and subdued light provide additional structure.

Digging can uproot plants, making floating or attached species more practical. Use only a mature, stable aquarium. Its broad natural habitat use does not remove sensitivity to deteriorating water quality.

Diet & feeding

Wild fish are probably omnivorous with a preference for aquatic invertebrates. In captivity, vary sinking dry foods with water fleas, mosquito larvae, bloodworm and shrimp. Gel foods can combine fruit, vegetables, spirulina and animal ingredients to broaden the menu.

Behaviour & compatibility

Companions must be too large to count as prey. A juvenile group may become incompatible as sexual maturity approaches. Formed pairs are usually relatively tolerant of each other but hostile toward additional conspecifics and similarly shaped fishes. Communities containing other cichlids require a very large aquarium and continued observation.

Breeding

Eggs are laid on a substrate and both parents care for the offspring. Cooperation within a pair should not be confused with acceptance of other aquarium residents.

Notes

The electric-blue line, often called EBJD, has an uncertain origin but appears to derive from a fixed natural mutation. These fish tend to remain smaller and some reports suggest reduced aggression, yet the same basic care principles apply. Older genus combinations such as Cichlasoma and Archocentrus may still appear on labels.