Jack Dempsey Overview
The Jack Dempsey (Rocio octofasciata) is a freshwater fish belonging to the family Cichlidae. It thrives at temperatures of 22–28 °C with a pH of 6.5–8.0, and requires a minimum tank volume of 200 litres. Known for its aggressive, territorial cichlid, it is considered a intermediate-level species. Named after the boxer Jack Dempsey for its fighting disposition; needs cichlid-appropriate tankmates. Water changes of 25–30 % weekly, stable parameters, and appropriate tank mates are key to long-term success with this species.
Jack Dempsey Scientific Classification
| Rank | Classification |
|---|---|
| Family | Cichlidae |
| Genus | Rocio |
| Species | Rocio octofasciata |
| Water type | freshwater |
| Native range | Neotropical|Hawaii|conterminous 48 United States |
Jack Dempsey Natural Habitat
Rocio octofasciata originates from Neotropical|Hawaii|conterminous 48 United States. It inhabits freshwater environments and is adapted to the water conditions found in its native range.
Jack Dempsey Appearance & Size
Adults reach 20–25 cm in length. The body is freshwater and the species displays characteristic coloration suited to its environment.
Jack Dempsey Behavior & Temperament
This species is described as a aggressive, territorial cichlid. It does not school and can be kept individually or in small numbers. Activity level is moderate. Named after the boxer Jack Dempsey for its fighting disposition; needs cichlid-appropriate tankmates.
| Trait | Value |
|---|---|
| Temperament | aggressive, territorial cichlid |
| Schooling | No |
| Activity level | moderate |
Jack Dempsey Water Requirements
| Parameter | Ideal Range | Notes |
|---|---|---|
| Temperature | 22–28°C (72–82°F) | Use a reliable adjustable heater |
| pH | 6.5–8 | Avoid sudden swings |
| Hardness (GH) | 9–20 dGH dGH | Soft to moderately hard |
| Ammonia | 0 ppm | Any detectable ammonia signals a problem |
| Nitrite | 0 ppm | Toxic even at low levels |
| Nitrate | <30 ppm | Manage through regular partial water changes |
| Min. tank | 200L (53 gal) | Larger tanks are easier to keep stable |
Interesting Facts About Jack Dempsey
- Iridescent blue-green spangles intensify with age and are most vivid in dominant males.
- The 'Electric Blue' Jack Dempsey is a naturally occurring colour mutation, not a hybrid.
- Parents guard eggs and fry vigorously; both male and female take active roles in brood care.
Species Related to Jack Dempsey
Related Species & Guides
This species profile was reviewed for biological accuracy and practical aquarium care guidance. For suspected illness or disease, test your water parameters first and consult an aquatic veterinarian if symptoms persist.