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No federal permit to keepJack Dempsey
Rocio octofasciata
Fishes › Cichlids (Cichliformes) › Cichlidae (Cichlids)
The Jack Dempsey (Rocio octofasciata) is a species of cichlid fish that is native to freshwater habitats from southern Mexico to Honduras, but also introduced elsewhere.
Care at a glance
Species-specific aquarium care
- Tank: At least 24 in long and 12 in front to back for one adult (adults commonly reach about 3.0 in / 7.5 cm; the largest recorded was 9.8 in).
- Water: Freshwater.
- Temperature: 72–86°F (range recorded for this species).
- pH: 7–8.
- Hardness: 9–20 dGH.
- Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
- Diet: Eats a varied diet: mix quality prepared foods with frozen and live foods. FishBase classes it as a carnivore.
Calculated from this species' own FishBase record: tank size from its typical adult length and swimming zone, water values from its recorded ranges. The group guide below fills in general care.
Care guide
Species care notes
- Tank: a base of at least 47 × 18 in (roughly 64 US gallons); space needed is rated “large tank”.
- Water: a fairly wide range, from slightly acidic to slightly alkaline, 68–86 °F, pH 6.5–8, 5–20 dGH.
- Behaviour: temperament peaceful; in a pair; not a community fish.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Ideally a soft, sandy substrate should be used though it’s not essential, and one or two flattish, water-worn rocks can also be included to provide potential spawning sites.”
- Diet: “Wild specimens are likely omnivorous but with a preference for aquatic invertebrates and suchlike.”
- Tankmates: “Can be kept in a well-chosen community arrangement alongside tankmates that are too large to be viewed as prey although a very large tank will be needed should you wish to keep it with other cichlids.”
- Breeding: “Biparental substrate spawner.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Central and South American cichlids
Applies to most species in this group. Habitat: Rivers and lakes of the Americas. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- Size ranges widely, from convicts at 5 in to Parachromis over 20 in; plan tank size for the adult fish.
- Most tolerate neutral, moderately hard water; strong filtration and rock or wood caves.
Climate & lighting
| Water | 75–82°F |
Diet
- Omnivorous cichlid pellets plus vegetables for herbivores (Vieja, Uaru) and meaty foods for predators (Parachromis).
Social life
- Territorial; breeding pairs can clear a whole tank.
Health watch
- Aggression and territorial injuries, especially when breeding; hole-in-the-head in poor water.
Understanding the animal
About this animal
About this animal
Its common name refers to its aggressive nature and strong facial features, likened to that of the famous 1920s boxer Jack Dempsey.
Quoted from the Wikipedia article “Jack Dempsey (fish)” (CC BY-SA 4.0) 174
In the wild
In the wild
From this species’ own FishBase record (habitat, bottom type, water and breeding data), not its family. Good care copies these conditions.1
| Where it lives | Lives in freshwater, in rivers and streams, mangroves. Uses both the bottom and open water. Occurs in swampy areas with warm, murky water. Found in weedy, mud-bottomed and sand-bottomed canals and drainage ditches. |
| Water it lives in | Freshwater, 72–86 °F (22–30 °C), pH 7–8, hardness 9–20 dH. |
| Climate | Tropical climate. |
| Behavior to plan for | Breeding: clutch tenders. |
What this means for care
- Keep water within its wild range, 72–86 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 92°F (up to 96°F in the hottest sampled areas) |
| Cool-season lows | about 63°F (down to 51°F in the coldest sampled areas) |
| Average temperature | 72–80°F across sampled records |
| Relative humidity | 74–79% on average (driest month about 69%) |
| Rainfall | about 1544 mm a year |
Measured at 174 wild occurrence records sampled against WorldClim 2.1 climate data (1970–2000 averages). Air conditions in the range are ecological context, not enclosure settings: microhabitats such as burrows, leaf litter or basking rocks can be cooler, warmer or more humid.
From the sources
From the sources
Quoted from the matching sections of reputable sources for this exact species. Specialist databases are used first; Wikipedia (community-edited, CC BY-SA 4.0) only fills gaps. Other sources are short credited quotes.
| Overview | The Jack Dempsey (Rocio octofasciata) is a species of cichlid fish that is native to freshwater habitats from southern Mexico to Honduras, but also introduced elsewhere. Its common name refers to its aggressive nature and strong facial features, likened to that of the famous 1920s boxer Jack Dempsey. — Wikipedia (community-edited) |
| Where it lives | Home ranges Population dynamics Growth parameters Max. ages / sizes Length-weight rel. Length-frequencies Mass conversion Recruitment Abundance Life cycle Reproduction Maturity Maturity/Gills rel. — FishBase |
| Reproduction | Parents incubate eggs and guard young. — FishBase |
| Appearance and size | The coloration changes as the fish matures from a light gray or tan with faint turquoise flecks to a dark purple-gray with very bright, iridescent blue, green, and gold flecks. Their colors change under stress. The dorsal and anal fins of mature males have long, pointed tips. — Wikipedia (community-edited) |
| Biology | Adults occur in swampy areas with warm, murky water. They are found in weedy, mud-bottomed and sand-bottomed canals and drainage ditches. They prefer coastal plains and slow moving waters of the lower river valleys. — FishBase |
Data and studies
The numbers
The numbers
Each bar is what one source reports. Where several sources weigh in, the dashed gold band marks their average.
Adult length
Common length to maximum recorded length. Measured as total length. Fish in home aquariums often stay smaller than wild records.
Water temperature
Range the species tolerates in nature; aim for the middle.
Minimum tank footprint
Seriously Fish recommends a tank base of at least 47 × 18 in (about 64 US gallons).
Sources for this sheet
- FishBase (Froese & Pauly, eds.), version 24.07 Peer-reviewed researchThe global scientific database on fishes, maintained by a consortium of research institutions; every value is referenced.
- Seriously Fish species profiles Experienced keeper or breederLong-running aquarium reference written and peer-checked by experienced fishkeepers and ichthyologists; each profile covers habitat, tank size, water, diet, behaviour and breeding.
- Merck Veterinary Manual: Management of aquarium fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Merck Veterinary Manual: Types and features of aquatic systems Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.
- iNaturalist (captive observations) Community referenceCommunity observation platform run by the California Academy of Sciences and National Geographic; observations marked captive show animals living in homes, zoos and aquariums.
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