Jack Dempsey

Rocio octofasciata

FreshwaterFish

Care at a glance

Temperature: 72–82°F (22–28°C)
pH: 6.0–7.5
Adult size: 9.8 in (25 cm)
Minimum tank: 55 gal (208 L)
Temperament: Aggressive
Social behavior: Solitary
Swim level: Middle
Difficulty: Medium
Breeding: Medium
Rarity: Very common
Origin: Central America (southern Mexico to Honduras)
Family: Cichlidae

Overview

Keep them singly or as an established pair in a tank of at least 208 liters, since they are large, territorial, and aggressive by default. They hold the middle of the water column and patrol their patch hard, so only pair them with robust, similarly sized tankmates and never small fish, which they will hunt. Run the water from 22 to 28 C with a pH of 6 to 7.5, and stay on top of water changes given how much they eat and produce. Feed quality pellets along with frozen and live foods like bloodworms, earthworms, and the odd feeder shrimp. Expect them to dig and rearrange the tank to suit themselves.

In the wild

Jack Dempseys come from slow, warm waters across Central America, from southern Mexico down to Honduras, where they hold territory among rocks, sunken wood, and dug-out pits in the substrate. To match that, give them a soft sand or fine gravel bottom they can dig, along with caves and rockwork they can claim as their own. Skip loose plants since they uproot anything not anchored well. Keep the tank from 22 to 28 C with a pH between 6 and 7.5.

Good to know

This is Rocio octofasciata, a cichlid in the family Cichlidae. Adults reach around 25 cm, so they need real room as they grow. They are substrate spawners that lay eggs on a cleaned flat surface, and both parents guard the eggs and fry. They are long-lived, often hitting 10 or more years in a well-kept tank.

Did you know

A calm, confident Jack Dempsey lights up with rows of blue-green flecks scattered across a dark body, and that sparkle gets stronger with age and good condition. The flip side is temperament. When they pair off and spawn, they turn extremely aggressive guarding the fry and will drive off anything that comes near, including much larger fish.