Keyhole cichlid

Water parameters

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

Tank and habitat

Substrate: fine.

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.
• Well suited to community tanks with peaceful species: tetras, rasboras, corydoras, otocinclus, and dwarf gouramis. They hold the lower and middle water 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

Cleithracara maronii, the keyhole cichlid, is a small, exceptionally peaceful cichlid from the Guianas and nearby northern South America. Steindachner described it in 1881 from the Maroni River on the French Guiana-Suriname border, and it ranges across most drainages of French Guiana along with Guyana, Suriname, and the Orinoco delta in Venezuela, with old records from Trinidad. It spent years in the genera Acara and Aequidens before Kullander and Nijssen placed it in its own genus, Cleithracara, in 1989; the name joins the Greek for lock with acara, the regional word for cichlid. It lives in slow, clear, often tannin-stained coastal creeks among submerged wood, roots, and marginal plants. The common name comes from a dark blotch on the upper flank that can stretch into a short bar resembling a keyhole. It is one of the very few cichlids safe in a planted tank, since it neither eats plants nor digs, and when alarmed it goes blotchy and presses against wood or rock to hide. Males reach roughly 10 cm or a little more, with females smaller, and records list a maximum around 10 cm standard length. Almost all trade fish are captive-bred.

Breeding

A biparental substrate spawner and an unusually gentle one. The pair picks a sheltered hard surface, the underside of a rock, a cave wall, or a broad leaf, and lays a clutch of a few hundred adhesive eggs that both parents tend. Their idea of defending the brood is mostly to put themselves between the eggs and a threat rather than to charge it, which is part of what makes them community-safe even while spawning. The eggs hatch in a few days, the fry are herded gently once free-swimming, and they take baby brine shrimp and microworms from the start. Keyholes are easily rattled while breeding, so heavy tank traffic or maintenance can make them eat the eggs or give up on a brood; a quiet, low-traffic spot helps. They spawn less often than prolific cichlids like convicts.

Common problems

Stress is the thing to manage. A keyhole that has gone dark, is hiding, and will not eat is almost always reacting to its surroundings, whether pushy tankmates, harsh open lighting, sudden movement at the glass, or repeated netting and maintenance. The answer is always the environment: calm companions, floating cover, subdued light, and a quiet location. Given that, they relax and stay out in view. Otherwise they are hardy in stable water and tolerate a fairly broad range of chemistry despite coming from soft, acidic blackwater, with tank-bred fish more adaptable than wild stock. Ich can show up on new fish and responds to raised temperature.

Bioload

Further reading

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