Photo: Bartosz Senderek (CC BY-SA 2.5) — via Wikimedia Commons
Keyhole Cichlid (Cleithracara maronii)
One of the gentlest cichlids in the hobby — a shy, slow-moving beauty that minds its own business in a peaceful community tank.
Will it live with a Keyhole Cichlid?
We compare each fish against your keyhole cichlid on temperament, size, water parameters and swimming zone. Set your tank size and filter the results.
- African Butterfly Cichlid✅ CompatibleSemi-aggressive · 8 cm · Medium care · 22–28 °C (72–82 °F)
- Peaceful + Semi-aggressive, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Agassiz's Dwarf Cichlid✅ CompatibleSemi-aggressive · 9 cm · Medium care · 24–30 °C (75–86 °F)
- Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
- Badis✅ CompatibleSemi-aggressive · 8 cm · Medium care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 22–28 °C, workable temperaments, and no predator-and-prey size gap.
- Bearded Corydoras✅ CompatiblePeaceful · 10 cm · Medium care · 18–24 °C (64–75 °F)
- Both are peaceful, and their water overlaps around 22–24 °C — no size, zone or temperament conflicts.
- Keep Bearded Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Black Kuhli Loach✅ CompatiblePeaceful · 8 cm · Easy care · 23–28 °C (73–82 °F)
- Both are peaceful, and their water overlaps around 23–28 °C — no size, zone or temperament conflicts.
- Bolivian Ram✅ CompatiblePeaceful · 8 cm · Medium care · 24–28 °C (75–82 °F)
- Both are peaceful, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
- Brilliant Rasbora✅ CompatiblePeaceful · 9 cm · Easy care · 22–28 °C (72–82 °F)
- Both are peaceful, and their water overlaps around 22–28 °C — no size, zone or temperament conflicts.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Brilliant Rasbora in a shoal of 6+ or it gets stressed and nippy.
- Burmese Loach✅ CompatiblePeaceful · 9 cm · Easy care · 22–28 °C (72–82 °F)
- Both are peaceful, and their water overlaps around 22–28 °C — no size, zone or temperament conflicts.
- Clown Pleco✅ CompatiblePeaceful · 9 cm · Medium care · 24–28 °C (75–82 °F)
- Both are peaceful, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
- Cockatoo Dwarf Cichlid✅ CompatibleSemi-aggressive · 8 cm · Medium care · 24–28 °C (75–82 °F)
- Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
- Dwarf Gourami✅ CompatibleSemi-aggressive · 8 cm · Medium care · 24–28 °C (75–82 °F)
- Peaceful + Semi-aggressive, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Giant Betta✅ CompatiblePeaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Giant Kuhli Loach✅ CompatiblePeaceful · 12 cm · Easy care · 24–30 °C (75–86 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Glass Catfish✅ CompatiblePeaceful · 8 cm · Medium care · 23–28 °C (73–82 °F)
- Both are peaceful, and their water overlaps around 23–28 °C — no size, zone or temperament conflicts.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Glass Catfish in a shoal of 6+ or it gets stressed and nippy.
- Goldeneye Dwarf Cichlid✅ CompatibleSemi-aggressive · 8 cm · Easy care · 24–28 °C (75–82 °F)
- Peaceful + Semi-aggressive, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
- Kuhli Loach✅ CompatiblePeaceful · 10 cm · Easy care · 24–30 °C (75–86 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Leopard Frog Pleco✅ CompatiblePeaceful · 9 cm · Medium care · 25–30 °C (77–86 °F)
- Compatible on the things that matter: shared water near 25–28 °C, workable temperaments, and no predator-and-prey size gap.
- Molly✅ CompatiblePeaceful · 10 cm · Easy care · 23–28 °C (73–82 °F)
- Compatible on the things that matter: shared water near 23–28 °C, workable temperaments, and no predator-and-prey size gap.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Murray River Rainbowfish✅ CompatiblePeaceful · 11 cm · Easy care · 15–26 °C (59–79 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Murray River Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Porthole Catfish✅ CompatiblePeaceful · 10 cm · Easy care · 22–28 °C (72–82 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Splashing Tetra✅ CompatiblePeaceful · 8 cm · Medium care · 22–28 °C (72–82 °F)
- Both are peaceful, and their water overlaps around 22–28 °C — no size, zone or temperament conflicts.
- Keep Splashing Tetra in a shoal of 6+ or it gets stressed and nippy.
- Spotted Rubbernose Pleco✅ CompatiblePeaceful · 12 cm · Medium care · 20–26 °C (68–79 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Thick-lipped Gourami✅ CompatiblePeaceful · 9 cm · Easy care · 22–28 °C (72–82 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Zebra Pleco✅ CompatiblePeaceful · 10 cm · Hard care · 26–30 °C (79–86 °F)
- Compatible on the things that matter: shared water near 26–28 °C, workable temperaments, and no predator-and-prey size gap.
- Afra Cichlid⚠️ With cautionSemi-aggressive · 10 cm · Medium care · 24–28 °C (75–82 °F)
- pH preferences only just meet (Keyhole Cichlid 6–7.5 vs Afra Cichlid 7.8–8.6) — target the overlap and acclimate slowly.
- Expect Afra Cichlid to harass Keyhole Cichlid at times; give dense cover and watch them at feeding.
- Your 80 L tank is below the ~150 L this pairing really wants — crowding raises aggression.
- Keep Afra Cichlid in a shoal of 6+ or it gets stressed and nippy.
- Auratus Cichlid⚠️ With cautionAggressive · 11 cm · Medium care · 23–28 °C (73–82 °F)
- Different pH ranges (6–7.5 vs 7.6–8.8); doable if you sit in the shared band, but not ideal long-term.
- Expect Auratus Cichlid to harass Keyhole Cichlid at times; give dense cover and watch them at feeding.
- Your 80 L tank is below the ~190 L this pairing really wants — crowding raises aggression.
- Keep Auratus Cichlid in a shoal of 6+ or it gets stressed and nippy.
- Clown Rasbora⚠️ With cautionPeaceful · 10 cm · Medium care · 23–28 °C (73–82 °F)
- Your 80 L tank is below the ~110 L this pairing really wants — crowding raises aggression.
- Keep Clown Rasbora in a shoal of 6+ or it gets stressed and nippy.
- Convict Cichlid⚠️ With cautionAggressive · 10 cm · Easy care · 21–28 °C (70–82 °F)
- Convict Cichlid and Keyhole Cichlid are close in size, but the aggressive one tends to dominate — add keyhole cichlid in a group to spread the pressure.
- Your 80 L tank is below the ~110 L this pairing really wants — crowding raises aggression.
- Daffodil Cichlid⚠️ With cautionSemi-aggressive · 10 cm · Medium care · 23–27 °C (73–81 °F)
- Different pH ranges (6–7.5 vs 7.8–9); doable if you sit in the shared band, but not ideal long-term.
- Daffodil Cichlid and Keyhole Cichlid are close in size, but the semi-aggressive one tends to dominate — add keyhole cichlid in a group to spread the pressure.
- Your 80 L tank is below the ~120 L this pairing really wants — crowding raises aggression.
- Electric Yellow Cichlid⚠️ With cautionSemi-aggressive · 10 cm · Medium care · 23–26 °C (73–79 °F)
- pH preferences only just meet (Keyhole Cichlid 6–7.5 vs Electric Yellow Cichlid 7.8–8.9) — target the overlap and acclimate slowly.
- Electric Yellow Cichlid is semi-aggressive and may chase or nip the smaller Keyhole Cichlid — plant heavily and break up sight lines.
- Your 80 L tank is below the ~200 L this pairing really wants — crowding raises aggression.
- Giant Danio⚠️ With cautionPeaceful · 10 cm · Easy care · 20–27 °C (68–81 °F)
- Your 80 L tank is below the ~110 L this pairing really wants — crowding raises aggression.
- Keep Giant Danio in a shoal of 6+ or it gets stressed and nippy.
- Golden Wonder Killifish⚠️ With cautionSemi-aggressive · 10 cm · Easy care · 22–28 °C (72–82 °F)
- Golden Wonder Killifish and Keyhole Cichlid are close in size, but the semi-aggressive one tends to dominate — add keyhole cichlid in a group to spread the pressure.
- Johanni Cichlid⚠️ With cautionAggressive · 10 cm · Medium care · 24–28 °C (75–82 °F)
- Different pH ranges (6–7.5 vs 7.8–8.6); doable if you sit in the shared band, but not ideal long-term.
- Expect Johanni Cichlid to harass Keyhole Cichlid at times; give dense cover and watch them at feeding.
- Your 80 L tank is below the ~200 L this pairing really wants — crowding raises aggression.
- Keep Johanni Cichlid in a shoal of 6+ or it gets stressed and nippy.
- Kribensis⚠️ With cautionSemi-aggressive · 10 cm · Easy care · 24–27 °C (75–81 °F)
- Expect Kribensis to harass Keyhole Cichlid at times; give dense cover and watch them at feeding.
- Paradise Fish⚠️ With cautionAggressive · 10 cm · Medium care · 16–26 °C (61–79 °F)
- Expect Paradise Fish to harass Keyhole Cichlid at times; give dense cover and watch them at feeding.
- Rosy Barb⚠️ With cautionSemi-aggressive · 10 cm · Easy care · 18–26 °C (64–79 °F)
- Rosy Barb and Keyhole Cichlid are close in size, but the semi-aggressive one tends to dominate — add keyhole cichlid in a group to spread the pressure.
- Keep Rosy Barb in a shoal of 6+ or it gets stressed and nippy.
- Rusty Cichlid⚠️ With cautionSemi-aggressive · 10 cm · Medium care · 24–28 °C (75–82 °F)
- Different pH ranges (6–7.5 vs 7.8–8.5); doable if you sit in the shared band, but not ideal long-term.
- Rusty Cichlid is semi-aggressive and may chase or nip the smaller Keyhole Cichlid — plant heavily and break up sight lines.
- Your 80 L tank is below the ~150 L this pairing really wants — crowding raises aggression.
- Tanganyikan Butterfly Cichlid⚠️ With cautionSemi-aggressive · 10 cm · Hard care · 24–28 °C (75–82 °F)
- Different pH ranges (6–7.5 vs 8–9); doable if you sit in the shared band, but not ideal long-term.
- Expect Tanganyikan Butterfly Cichlid to harass Keyhole Cichlid at times; give dense cover and watch them at feeding.
- Your 80 L tank is below the ~130 L this pairing really wants — crowding raises aggression.
- Topaz Cichlid⚠️ With cautionSemi-aggressive · 10 cm · Medium care · 23–28 °C (73–82 °F)
- Topaz Cichlid and Keyhole Cichlid are close in size, but the semi-aggressive one tends to dominate — add keyhole cichlid in a group to spread the pressure.
- Upside-down Catfish⚠️ With cautionPeaceful · 10 cm · Easy care · 22–26 °C (72–79 °F)
- Your 80 L tank is below the ~115 L this pairing really wants — crowding raises aggression.
- Alligator Gar⛔ Not recommendedAggressive · 250 cm · Hard care · 24–28 °C (75–82 °F)
- Alligator Gar (250 cm) is big enough to swallow the 10 cm Keyhole Cichlid whole.
- Alligator Gar is aggressive and may chase or nip the smaller Keyhole Cichlid — plant heavily and break up sight lines.
- Your 80 L tank is below the ~3785 L this pairing really wants — crowding raises aggression.
- Clown Knifefish⛔ Not recommendedAggressive · 90 cm · Hard care · 24–28 °C (75–82 °F)
- Keyhole Cichlid is bite-sized to a 90 cm predatory clown knifefish — it will be eaten.
- Expect Clown Knifefish to harass Keyhole Cichlid at times; give dense cover and watch them at feeding.
- Your 80 L tank is below the ~750 L this pairing really wants — crowding raises aggression.
- Fire Eel⛔ Not recommendedSemi-aggressive · 100 cm · Medium care · 24–28 °C (75–82 °F)
- Fire Eel (100 cm) is big enough to swallow the 10 cm Keyhole Cichlid whole.
- Expect Fire Eel to harass Keyhole Cichlid at times; give dense cover and watch them at feeding.
- Your 80 L tank is below the ~380 L this pairing really wants — crowding raises aggression.
- Koi⛔ Not recommendedPeaceful · 90 cm · Medium care · 4–28 °C (39–82 °F)
- Keyhole Cichlid is bite-sized to a 90 cm koi — it will be eaten.
- Your 80 L tank is below the ~3800 L this pairing really wants — crowding raises aggression.
- Redtail Catfish⛔ Not recommendedAggressive · 120 cm · Hard care · 24–27 °C (75–81 °F)
- Keyhole Cichlid is bite-sized to a 120 cm predatory redtail catfish — it will be eaten.
- Redtail Catfish is aggressive and may chase or nip the smaller Keyhole Cichlid — plant heavily and break up sight lines.
- Your 80 L tank is below the ~5700 L this pairing really wants — crowding raises aggression.
- Spotted Gar⛔ Not recommendedAggressive · 90 cm · Hard care · 18–26 °C (64–79 °F)
- Size gap is too large (90 vs 10 cm): Spotted Gar will treat Keyhole Cichlid as food.
- Spotted Gar is aggressive and may chase or nip the smaller Keyhole Cichlid — plant heavily and break up sight lines.
- Your 80 L tank is below the ~600 L this pairing really wants — crowding raises aggression.
- Wels Catfish⛔ Not recommendedAggressive · 300 cm · Hard care · 15–25 °C (59–77 °F)
- Wels Catfish (300 cm) is big enough to swallow the 10 cm Keyhole Cichlid whole.
- Wels Catfish is aggressive and may chase or nip the smaller Keyhole Cichlid — plant heavily and break up sight lines.
- Your 80 L tank is below the ~20000 L this pairing really wants — crowding raises aggression.
- Wolf Cichlid⛔ Not recommendedAggressive · 72 cm · Hard care · 24–30 °C (75–86 °F)
- Size gap is too large (72 vs 10 cm): Wolf Cichlid will treat Keyhole Cichlid as food.
- Wolf Cichlid is aggressive and may chase or nip the smaller Keyhole Cichlid — plant heavily and break up sight lines.
- Your 80 L tank is below the ~760 L this pairing really wants — crowding raises aggression.
Compatibility is computed from each species' care data — a strong starting point, not a guarantee. Individual temperament varies, so always introduce new fish slowly and watch them.
Keyhole Cichlid care specs
- Care level
- Easy
- Breeding
- Medium
- Max size
- 10 cm (3.9 in)
- Min tank size
- 80 L (21.1 gal)
- Temperature
- 22–28 °C (72–82 °F)
- pH
- 6–7.5
- Hardness
- 2–12 dGH
- Lifespan
- 5–8 years
- Diet
- Omnivore
- Swim level
- Middle
- Group size
- 2+ (shoaling)
- Family
- Cichlidae
- Origin
- South America — Orinoco basin and coastal rivers of Venezuela and Trinidad
What is a Keyhole Cichlid?
The Keyhole Cichlid (Cleithracara maronii) is a small South American cichlid that consistently defies the family’s aggressive reputation. Adults reach about 10 cm (4 in) and wear a soft, sandy-tan base colour interrupted by two signature markings: a dark lateral stripe through the eye and a bold black teardrop blotch on the upper flank — the “keyhole” that gives the fish its common name. The blotch can intensify or fade with mood, making it a surprisingly expressive fish to watch.
Where most cichlids are territorial and combative, keyholes are cautious and conflict-averse. They explore their tank methodically, retreat to cover when startled, and rarely harass tank-mates. That combination of cichlid intelligence, readable body language, and genuine peacefulness makes them one of the most appealing choices for an aquarist who wants cichlid character without cichlid drama. Care level is easy, and a well-kept pair can live 5–8 years.
Where do Keyhole Cichlids come from in the wild?
Keyhole Cichlids are native to the Orinoco basin and coastal rivers of Venezuela and Trinidad — slow, warm waterways ranging from clear to tannin-stained blackwater. The substrate is typically soft sand and leaf litter, shaded by overhanging vegetation and driftwood, with water that is soft and gently acidic. Replicating those conditions — even loosely — keeps the fish confident and in good colour rather than hiding at the back of the tank permanently.
What tank size and setup does a Keyhole Cichlid need?
An 80-litre (21-gallon) aquarium is the practical minimum for a pair. A longer footprint (around 90 cm / 36 in) is preferable to a tall one because these are middle-water fish that use horizontal space. Furnish the tank with dense planting around the back and sides, leaving a central open swimming lane. Driftwood, smooth rocks, and dried Indian almond leaves create the sheltered, dimly lit feel the fish expects. Floating plants reduce surface light and encourage keyholes to spend more time in the open. Substrate can be fine sand or small gravel; the fish occasionally dig lightly around flat stones before spawning. Keep filtration gentle — strong current is not natural to this species.
What water parameters do Keyhole Cichlids need?
- Temperature: 22–28 °C (72–82 °F). A stable mid-range of around 25–26 °C is ideal for long-term health.
- pH: 6.0–7.5. Captive-bred fish are reasonably adaptable, but conditions below pH 7.0 are more natural and generally preferred.
- Hardness: 2–12 dGH. Soft to moderately hard water is fine; very hard or alkaline tap water should be tempered with RO or rain water if hardness regularly exceeds the upper limit.
Stability matters as much as hitting exact numbers. Cycle the tank fully before adding fish and maintain weekly partial water changes of around 25–30 %. Avoid drastic top-ups with water of a very different temperature — sudden swings cause stress and suppress the immune system.
What do Keyhole Cichlids eat?
Keyhole Cichlids are omnivores with a broad palate, which makes feeding straightforward. A quality sinking pellet or cichlid-specific micro-pellet forms a reliable staple. Supplement this regularly with live or frozen foods — bloodworm, daphnia, brine shrimp, and white mosquito larvae are all accepted eagerly and support good colour and condition. Blanched vegetables such as zucchini or spinach can be offered occasionally; some individuals take to them readily, others ignore them.
Feed once or twice a day, using an amount the fish consume within two or three minutes. Because keyholes are cautious feeders they may lose out to faster or more assertive tank-mates; if this is an issue, target feeding with a pipette or feeding ring ensures they get their share. Remove uneaten food promptly to keep water quality high.
How do Keyhole Cichlids behave — and what fish can live with them?
Keyhole Cichlids are genuinely peaceful — not just “peaceful for a cichlid” — and can be kept in a well-chosen community tank. Their temperament is best described as cautious and observant. They spend much of the day cruising the middle of the tank, investigating objects and watching their surroundings, but retreat to cover at sudden movements or when more assertive fish encroach on their space. A pair will develop a recognisable bond and often move around the tank together.
Good tank-mate candidates are similarly sized, non-aggressive fish that occupy different zones of the water column: small tetras (rummy-nose, cardinal, ember), pencilfish, corydoras catfish, dwarf plecos, and other peaceful South American species all work well. Other small, peaceful cichlids such as German blue rams or Bolivian rams can coexist in a large enough tank. Avoid fast, boisterous fish that outcompete them at feeding, aggressive fin-nippers, or any large cichlid that treats them as a target.
For a full compatibility breakdown, see Keyhole Cichlid tank mates.
How do you tell male from female Keyhole Cichlids apart?
Sexual dimorphism in Keyhole Cichlids is subtle and is only reliable in fully mature adults. Males are marginally larger and tend to develop slightly more pointed dorsal and anal fins, whereas females remain a little smaller and rounder in the belly — particularly when conditioning for spawning. Colour and patterning are essentially identical between the sexes.
Because the differences are so slight, the most reliable approach is to purchase a group of five or six juveniles and grow them on together, allowing natural pairing. Alternatively, buy from a seller who can confirm sexed adults from spawning records.
How do Keyhole Cichlids breed?
Keyhole Cichlids are open-substrate or crevice spawners. A conditioning pair will clean a flat stone, broad leaf, or the inside of a clay pot before depositing a modest clutch — typically a few dozen to around 100 eggs. Both parents guard and fan the spawn; fry are free-swimming within a week or so at typical temperatures.
To encourage spawning, raise the temperature toward the upper range (27–28 °C / 80–82 °F) and increase live or frozen food portions. A dedicated breeding tank removes the risk of other fish disrupting the spawn. Raising fry requires appropriate micro-foods — infusoria or commercial fry food initially, then baby brine shrimp — which is why breeding difficulty is rated medium.
What diseases are common in Keyhole Cichlids?
Keyhole Cichlids are not especially disease-prone, but they share the vulnerabilities of most freshwater cichlids. Ich (white-spot disease) is the most common trigger event and almost always follows a temperature drop or the introduction of unquarantined fish. Hole-in-the-head disease (HITH) has been associated with poor water quality and dietary deficiencies in cichlids generally, and keyhole cichlids are not immune. Bacterial infections and fin damage are typically secondary to stress — overcrowding, bullying by tank-mates, or chronic poor water quality.
Prevention centres on three things: a fully cycled and stable tank, quarantining all new fish and plants for at least two to four weeks before introduction, and a varied diet that avoids heavy reliance on any single food type. A fish that is confident, feeding well, and displaying full colour is a healthy fish.
Health note: medication dosing and disease diagnosis are beyond the scope of a care profile. For sick fish, confirm symptoms against a reputable veterinary or fish-health source before treating.
How long do Keyhole Cichlids live?
With good care, Keyhole Cichlids live 5–8 years — a solid lifespan for a fish of their size that reflects how undemanding they are when their basic needs are met. The key variables are water quality and stress: a pair kept in a stable, well-planted tank with appropriate tank-mates at the quieter end of their temperature range will reliably hit the upper end of that range. Chronic stress, poor diet, or unstable water chemistry tends to compress it. These are not delicate fish, but they reward consistency.
Frequently asked questions
Can Keyhole Cichlids live with other cichlids?
Yes, as long as the other cichlids are similarly sized and peaceful. They do well alongside German blue rams or Bolivian rams but should not share a tank with large or aggressive cichlids that will bully them — keyholes are shy and will hide rather than fight back.
Why is it called the Keyhole Cichlid?
The name comes from the distinctive black blotch on the upper flank, roughly behind the dorsal fin, which in some individuals is drawn out into a shape resembling an old-fashioned keyhole.
What you need to keep a keyhole cichlid
The baseline is a heated, filtered 80 L+ tank: a reliable heater to hold 22–28 °C (72–82 °F), a gentle filter that won't batter a keyhole cichlid in the current, and a tight-fitting lid. Cycle the tank fully before adding any fish.
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