Origin
Rocio octofasciata inhabits the slow-moving waters of southern Mexico, Belize, Guatemala, and Honduras. They reach 8–10 inches in captivity.
Wild fish are dark with iridescent blue-green spots. The Electric Blue Jack Dempsey (EBJD) is a captive-bred mutation with stunning bright blue body color but reduced vigor.
Tank Setup
Minimum 75-gallon for a single. 125-gallon for a pair.
Heavy filtration. Driftwood, large rocks, sand substrate. Minimal plants — Jack Dempseys uproot them.
Water Parameters
Temperature: 74–82°F.
pH: 6.5–8.0.
GH: 8–15.
Nitrates: under 30 ppm.
Diet
Carnivore. NLS Cichlid Formula or Hikari Cichlid Gold, frozen krill, earthworms, occasional crickets.
Feed 1–2× daily.
Aggression Management
Jack Dempseys are aggressive toward conspecifics and most cichlids. A bonded breeding pair is the safest combination — they will defend together against everything else.
Compatible tank mates: large plecos, silver dollars, severums, large catfish. All in 125+ gallon tanks.
Electric Blue Jack Dempsey
EBJDs are double-recessive mutants. They are smaller, less aggressive, and slower-growing than wild-type. They also suffer from immune deficiencies and shorter lifespans (4–6 years vs 10+ for wild type).
Buy from established breeders only. Pet store EBJDs are often weak.