Jack dempsey - Cichlasoma octofasciatum

Scientific name: Cichlasoma octofasciatum

Common name: Jack dempsey

Family: Cichlidae

Usual size in fish tanks: 15 - 20 cm (5.91 - 7.87 inch)

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Recommended pH range for the species: 7 - 8.5

Recommended water hardness (dGH): 18 - 30°N (321.43 - 535.71ppm)

0°C 32°F30°C 86°F

Recommended temperature: 25 - 28 °C (77 - 82.4°F)

The way how these fish reproduce: Spawning

Where the species comes from: Central America

Temperament to its own species: aggressive/territorial

Temperament toward other fish species: aggressive/territorial

Usual place in the tank: Bottom levels

Tank Requirements

The Jack Dempsey Cichlid (Cichlasoma octofasciatum) is a large and aggressive cichlid that requires a spacious aquarium of at least 55 gallons (208 liters) for a single adult. These fish thrive in stable water conditions with a pH range of 7.0-8.5 and water hardness between 18-30°N (321.43-535.71 ppm). The water temperature should be maintained between 25-28°C (77-82.4°F).

Due to their territorial and aggressive nature, it is crucial to provide plenty of hiding places in the tank, using rocks, caves, and driftwood. Sand or smooth gravel substrate is recommended, as they enjoy digging. Strong filtration is essential to keep the water clean, as Jack Dempseys are large fish that produce significant waste. Weekly water changes of at least 20% will help maintain water quality.

Tankmates

Jack Dempseys are highly territorial and aggressive, especially toward fish of similar size or appearance. Suitable tankmates should be robust and able to tolerate their aggressive behavior. Avoid housing them with smaller or peaceful fish, as they may be attacked or eaten. Some potential tankmates include:

• Oscar Cichlid (Astronotus ocellatus)
• Green Terror Cichlid (Aequidens rivulatus)
• Firemouth Cichlid (Thorichthys meeki)
• Convict Cichlid (Archocentrus nigrofasciatus)

Keep an eye on aggression levels, especially during breeding, and make sure the tank is large enough for each fish to establish its own territory.

Feeding

Jack Dempsey Cichlids are omnivorous and will eat a wide variety of foods. Their diet should include a high-quality pellet or flake food as a staple, supplemented with live or frozen foods such as bloodworms, brine shrimp, and earthworms. They also enjoy small fish, snails, and insects, making them excellent hunters in a natural setting.

In addition to protein-rich foods, they benefit from the occasional vegetable matter. You can offer them blanched lettuce, peas, or cucumber to ensure a balanced diet. Feed them once or twice a day, only as much as they can consume in a few minutes. Overfeeding can lead to obesity and water quality issues, so it’s essential to avoid excessive feeding.

Sexing

Mature males tend to be larger and display more vibrant coloration compared to females. One key indicator is the coloration on the dorsal fin: the top edge of the dorsal fin in males is often tinged with dark red. Additionally, males have a pointed genital papilla, which is more easily visible during breeding periods.

Breeding

Breeding Jack Dempsey Cichlids is relatively straightforward if the right conditions are provided. The water should be slightly acidic (with a pH below 7.0) and relatively soft, with a dGH of around 12°N. Increasing the water temperature to the upper range of their tolerance (closer to 28°C or 82.4°F) can encourage spawning.

The female will lay her eggs on a flat surface, such as a cleaned rock or a slate. After the eggs are fertilized, both parents will guard the eggs and the territory aggressively. The eggs usually hatch within 3-4 days, depending on the temperature, and the fry will become free-swimming after about a week. At this stage, the fry can be fed on newly hatched brine shrimp or finely crushed flake food.

Lifespan

With proper care, Jack Dempsey Cichlids can live for 10-13 years, and some have been known to live even longer. Providing them with a clean, stable environment, along with a well-balanced diet, is key to ensuring they reach their full lifespan potential.

Short Description

The Jack Dempsey Cichlid is a popular species among cichlid enthusiasts due to its striking appearance and bold personality. However, its aggressive and territorial nature makes it better suited for experienced aquarists who can provide a large, well-structured tank. These fish are native to Central America, where they inhabit slow-moving rivers and lakes. In the aquarium, they require strong filtration, regular water changes, and plenty of hiding spaces to manage their territorial behavior.

Picture credit

Thanks to Kevin and Corey Bower who have allowed us to use the pictures. Also thanks to Jeremie and Ben! Some pictures were bought from jjphoto.dk.