Keyhole cichlid

Water parameters

Tolerated range for this species. Aim for the middle of each band rather than the extremes.

Tank and habitat

Substrate: sand.

Behavior

Plant interaction: plant safe.

Feeding

Omnivore that accepts most foods without complaint. Pellets, flake, frozen bloodworm, frozen brine shrimp, frozen daphnia, live blackworms, and blanched vegetables. They feed from the bottom and midwater, methodically picking through substrate and surfaces. Not competitive at feeding time; in tanks with assertive species they may hang back and miss out. Targeted feeding or after-lights-out feeding helps if competition is an issue. Feed twice daily. Live food brings out richer body color and encourages breeding behavior.

Compatibility

• The calmest cichlid in the hobby. Keyholes are so non-aggressive that they lose territorial disputes to tetras. A breeding pair defends its spawn site but does so with half-hearted chasing rather than real combat.
• Genuinely suitable for community tanks with peaceful species: tetras, rasboras, corydoras, otocinclus, and dwarf gouramis. They occupy the lower and middle water column and mostly ignore tankmates.
• Stress-sensitive despite being hardy in terms of water chemistry. Loud noises, aggressive tankmates, or frequent tank disturbances cause them to hide, lose color, and refuse food. They need a calm environment.
• Pairs bond and often stay together long-term. They display interesting parental behavior without the tank-destroying aggression that comes with most cichlid breeding.

Origin and habitat

Described from the Maroni River in French Guiana by Steindachner in 1881. Occurs across most river drainages in French Guiana, Guyana, and Suriname, as well as the Orinoco delta region in Venezuela; historical records also place it on the island of Trinidad, though it may not have been collected there since the 1960s. Long known under the synonym Aequidens maronii before being separated into the monotypic genus Cleithracara by Kullander and Nijssen in 1989. The genus name combines Greek kleithron ("lock") with the Guaraní acará ("cichlid"), derived from the fish's common name in the hobby. Inhabits small, clear coastal creeks and tributaries with little current, abundant decaying wood, submerged roots, and marginal vegetation; the water is often tannin-stained. The dark lateral blotch that gives the species its common name sometimes extends into a short stripe resembling a keyhole shape. One of the most peaceful cichlids in the hobby. They don't eat plants or burrow in substrate, making them one of the few cichlids suitable for planted tanks (FishKeepingWorld). When startled or stressed, they develop blotchy coloration and press against rocks or driftwood to camouflage themselves. Shy fish that benefit from the presence of peaceful tankmates like tetras, pencilfish, and Corydoras. Most fish in the trade are captive-bred.

Breeding

Substrate spawner. A pair selects a sheltered surface (underside of a rock, inside a cave, broad leaf) and deposits 100-300 adhesive eggs. Both parents guard the clutch, but aggression toward other fish is minimal compared to any other cichlid. They more often position themselves between the threat and the eggs rather than charging. Eggs hatch in 3-4 days. Fry become free-swimming 4-5 days later and are herded gently by both parents. Parental care lasts 3-6 weeks. Fry eat baby brine shrimp and microworms from the start. Keyhole cichlids are easily spooked during breeding; too much tank traffic or maintenance can cause them to eat the eggs or abandon the brood. A calm, low-traffic location for the tank improves breeding success. Spawning frequency is lower than prolific species like convicts; expect a brood every 6-10 weeks in good conditions.

Common problems

Stress response is the main management issue. Keyholes darken, hide, and stop eating when conditions aren't right. Common stressors: aggressive tankmates, overly bright lighting without cover, sudden movements near the tank, and frequent netting or tank maintenance. The fix is always environmental: calm tankmates, floating plants for cover, dim lighting, and minimal disturbance. In the right setup, they're relaxed and visible all day. Health problems are uncommon in stable water. Ich can appear in newly purchased fish; treat with temperature elevation. The species tolerates a fairly wide parameter range (pH 6.0-7.5, temperature 22–28°C) despite coming from soft acidic water in the wild. Tank-bred stock is more adaptable than wild-caught. Lifespan is 8-10 years.

Bioload

Further reading

• How to cycle a fish tank
• Stocking ideas by tank size