Keyhole Cichlid
Cleithracara maronii
Also known as: Keyhole
Quick Facts
- Adult size: 10-12 cm (4-4.7 inches)
- Minimum tank size: 110 litres (29 gallons)
- Lifespan: 8–10 years
- Temperament: peaceful
- Swimming level: middle-and-bottom
- Diet: omnivore
- Minimum group size: 1
- Difficulty: intermediate
Water Parameters
- Temperature: 22–26°C
- pH: 6–7.5
- Hardness (GH): 36–179 ppm (2–10 dGH)
Values above are general hardness (GH). For carbonate hardness (KH), the buffer that keeps pH stable, see the water parameters guide.
Care Summary
The cichlid for people who have been told cichlids cannot live in a community, the keyhole is a soft-bodied, retiring South American fish named for the keyhole-shaped dark blotch on its flank. It is genuinely peaceful to the point of timidity, changing to a mottled camouflage when nervous and fading when stressed, so it rewards a quiet, well-planted tank with plenty of cover and calm tankmates more than almost any other cichlid. Hardy and long-lived once settled, it forms stable pairs that make undemanding, attentive parents without the tank-clearing aggression of convicts or oscars. It needs space (a tank around 110 litres) and patience while it gains confidence, but it asks for little else. An excellent introduction to cichlid keeping for a peaceful community.
Tankmates
One of the few genuinely community-safe cichlids, the keyhole is so peaceful and shy that its main problem is being bullied or outcompeted, not causing trouble. Best kept as a single specimen or a bonded pair in a planted tank with caves and broken sightlines, which it needs to feel secure; in an open or busy tank it hides and pales. Compatible with most calm, medium-sized community fish: peaceful tetras and rasboras, corydoras, plecos, rainbowfish, and other gentle species. Keep it away from boisterous or nippy fish (tiger barbs, serpae tetras) and from aggressive cichlids, which dominate it. It will eat dwarf shrimp but ignores plants. Even when breeding it is far less territorial than most cichlids.
Compatible with
- Harlequin Rasbora
- Congo Tetra
- Bronze Corydoras
- Bristlenose Pleco
- Pearl Gourami
- Dwarf Neon Rainbowfish
Avoid keeping with
- Betta
- Convict Cichlid
- Large Cichlids
- Tiger Barb
- Serpae Tetra
- Cherry Shrimp
Common Problems
- shyness and hiding without enough cover
- stress and fading colour from boisterous tankmates
- being outcompeted at feeding
- ich
Sources: seriouslyfish.com, fishbase.org · Last updated: 2026-06-20