A robust, highly territorial Central American cichlid named after the aggressive 1920s boxer, William 'Jack' Dempsey. They exhibit beautiful iridescent blue, green, and gold spangling over a dark background. As aggressive diggers and plant destroyers, they require a tank with sturdy decor. They are best kept as a single wet pet or in a large tank with other similarly sized, robust Central American cichlids.
At a Glance
Tank Requirements
Water Parameters
Temperament & Compatibility
Available Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Standard Adult
The standard wild-type coloration and adult size. Highly aggressive and requires a very large footprint.
Same care requirements as the base species
Also known as: Wild Type, Regular Jack Dempsey
Juvenile (Grow-out)
Juvenile Jack Dempseys are frequently sold at 4-5cm. They can be temporarily housed in smaller aquariums but will grow quickly and become increasingly territorial as they mature.
Differs in 6 traits from base species
Also known as: Baby JD, Young Jack Dempsey
Electric Blue (EBJD)
A brilliant neon blue morphological variant. The EBJD is significantly smaller, much more peaceful, and notoriously more fragile than the wild type. They grow slower and are prone to parasitic infections and internal issues.
Differs in 4 traits from base species
Also known as: EBJD, Blue Jack Dempsey, Electric Blue
Jack Dempsey Care Summary
The Jack Dempsey, scientifically known as Rocio octofasciata, belongs to the Cichlids - Central American family group. Adults reach a maximum size of approximately 25 cm and have a compressed body shape with a moderate growth rate. Classified as aggressive, this species primarily occupies the mid-level and bottom zones of the aquarium and produces a high level of biological waste.
To thrive, the Jack Dempsey requires a freshwater only aquarium with a minimum volume of 200 litres and a tank length of at least 120 cm. Water temperature should be maintained between 22°C and 30°C, with a pH range of 6.5–8 and a general hardness of 5–15 dGH. A moderate water flow is preferred. To replicate their natural habitat, the tank should include sand (sifters), driftwood (digestion/hiding), and smooth gravel (sensitive barbels).
Jack Dempsey can be kept singly or in a group, making them flexible additions to most setups. Keepers should be aware that this species will prey on fish small enough to fit in its mouth, can be aggressive toward its own kind, will defend a territory within the tank, and may uproot or eat live plants. This species is available in 3 varieties: Standard Adult, Juvenile (Grow-out), and Electric Blue (EBJD). Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.
Similar Species
Texas Cichlid
Herichthys cyanoguttatus
The Texas Cichlid is the only cichlid species native to the United States. Known for their striking pearlescent blue/green spots and extreme territorial behavior, they require large tanks and robust filtration. They are notorious for rearranging aquariums, digging massive pits, and destroying live plants.
Firemouth Cichlid
Thorichthys meeki
A popular Central American cichlid famous for the bright red coloration on its throat and belly, which it flares to intimidate rivals. They are earth-eaters, constantly sifting sand for food. While territorial, especially during breeding, they are relatively peaceful for a cichlid of their size compared to larger Central American counterparts.
Convict Cichlid
Amatitlania nigrofasciata
One of the most ubiquitous and hardy cichlids in the hobby. Named for their black-and-white prison stripe pattern, Convicts are infamous for their intense aggression, especially when breeding (which they do readily). They are intelligent, wet pets that rearrange their tank décor constantly. Best kept in species-only tanks or with other robust Central American cichlids.
Oscar
Astronotus ocellatus
A highly intelligent, large, and personable South American cichlid often described as a 'water dog'. They are notoriously messy eaters, heavy waste producers, and will enthusiastically rearrange tank decor and uproot plants. Any fish small enough to fit in their mouth will be eaten. They require excellent filtration and strict water maintenance.
Flowerhorn Cichlid
Cichlasoma sp. hybrid
A man-made hybrid cichlid famous for its vibrant colors, extreme interactive personality, and the large nuchal hump (kok) on its head. They are incredibly aggressive 'wet pets' that will attack hands, tank mates, and equipment. They have a massive bioload, dig constantly, and must almost always be kept completely alone.
African Jewel Cichlid
Hemichromis bimaculatus
A strikingly beautiful but notoriously aggressive West African riverine cichlid. Unlike the alkaline-loving Rift Lake cichlids (e.g., Mbuna), Jewel Cichlids prefer neutral, softer water parameters. They are renowned for their brilliant red breeding dress and iridescent blue spots, but also for their extreme territoriality, especially when forming pairs and spawning. They are avid diggers and will uproot most plants.