Cichlasoma octofasciatum

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Cichlasoma octofasciatum, also known as the Blue Electric Jack Dempsey, is a striking captive-bred form of the Central American cichlid historically known in the literature as Cichlasoma octofasciatum. Its metallic blue colour is immediately eye-catching, but its beauty comes with a territorial temperament and substantial adult size. This fish is best suited to an aquarist able to provide a large aquarium, strong filtration and enough structure for each individual to establish a territory. The blue form is selected primarily for its appearance, while its basic requirements remain those of the wild species.

General description of the species

Cichlasoma octofasciatum is a Central American cichlid commonly associated with the Jack Dempsey group. The supplied name, Cichlasoma octofasciatum, remains widely used in the trade, while modern classification generally places the species in the genus Rocio. It is a hardy and fairly adaptable fish, but its adult size and behaviour make it demanding. The Blue Electric Jack Dempsey has a more uniform and luminous blue colour than the natural form. It is fairly common in the aquarium trade, but it is not suited to small community aquariums. A spacious aquarium, hiding places and stable water quality are essential.

Geographical origin and biotope

The species originates from the Atlantic drainage of Central America, particularly from Mexico southward to Honduras, with records from several watersheds in Guatemala and Belize. In Honduras, it inhabits warm freshwater environments with calm or moderately flowing water, including streams, ponds and quiet sections of rivers. The biotope commonly includes sand, gravel, mud, roots and stones. Vegetation may be sparse within the channel but denser along the banks. In an aquarium, a temperature of 24 to 28 °C and slightly acidic to alkaline water are suitable.

Precise location and local name

In Honduras, Cichlasoma octofasciatum is associated with freshwater systems on the Atlantic side of the country and inland basins connected to that region. Aquarium and trade sources mainly use the English name Jack Dempsey, rather than a single standardized Honduran local name. The term Blue Electric Jack Dempsey refers to the blue aquarium form and not to a distinct geographical population. In the wild, it uses quiet areas with roots, stones or other shelters that can be defended. A blue captive strain should not be confused with a fish collected from a precisely identified locality.

Appearance and physical characteristics

Cichlasoma octofasciatum has a deep, sturdy and laterally compressed body, a broad head, a well-developed mouth and elongated dorsal and anal fins. The Blue Electric form is distinguished by electric-blue iridescence across the body, operculum and fins, often with darker markings that vary in visibility. Colour changes with mood, age, lighting and social status. Adults may reach approximately 25 cm under good conditions, requiring a substantial aquarium. As in many cichlids, the fins become more pronounced with maturity and the overall body takes on a powerful appearance.

General diet

Cichlasoma octofasciatum is an opportunistic omnivore that naturally consumes small invertebrates, aquatic larvae, crustaceans, small fish and some plant matter. In aquaria, its diet should be based on quality pellets for large cichlids, supplemented with frozen foods such as shrimp, bloodworms or krill. Some plant matter can be provided through foods containing algae or suitable vegetables. Variety is preferable, while excessive fatty foods and feeder fish from unreliable sources should be avoided. Moderate portions offered once or twice daily help reduce waste and maintain good body condition.

Essential data

• Name of the original river: not specified
• Local name used: Jack Dempsey
• Origin of the scientific name: historical combination Cichlasoma octofasciatum
• Full-name etymology: Cichlasoma is an old genus name; octofasciatum comes from the Latin octo, eight, and fascia, band, referring to the barred pattern
• Common/vernacular names: Jack Dempsey, Blue Electric Jack Dempsey, Jack Dempsey cichlid
• Family: Cichlidae
• Subfamily: Cichlinae
• Name pronunciation: sik-la-SO-ma ok-to-fas-see-A-tum
• Discovery: Charles Tate Regan, 1903
• Maximum adult size: approximately 25 cm
• Water temperature and pH: 24 to 28 °C; pH 6.5 to 8.0
• Watercourse appearance and surrounding vegetation: calm to moderately flowing water, wooded or vegetated banks, submerged roots and shelters
• Typical tankmates: large robust livebearers, full-grown characins and compatible Central American cichlids; cohabitation remains risky
• Temperament and behaviour: territorial, a substrate digger and especially aggressive when breeding
• Water depth: shallow to moderately deep areas
• Sexual dimorphism: males are generally larger, with more developed fins and stronger colour; identification can vary
• Bottom structure and flow: sand, gravel, mud, stones and roots; slow to moderate flow

In your aquarium

For success with Cichlasoma octofasciatum, provide an aquarium of at least 300 litres for an adult, with oversized filtration, well-oxygenated water and regular water changes. Use a stable layout of rocks, roots and shelters, since this fish may move the substrate. Avoid small tankmates that could be harassed or swallowed. The main challenge is managing its territorial aggression, especially when a pair forms. A varied diet, adequate swimming space and consistent water quality will support longevity and help display its electric-blue iridescence.