Should I buy it?
Keyhole cichlid
Cleithracara maronii
The most community-compatible cichlid in the hobby. Shy, peaceful, and genuinely safe with most tank mates except shrimp during spawning.
Keyhole cichlid tank mates · 200L tank size hub
peaceful · intermediate care
Sources & confidencehigh · partially verified · beginner: good
Checked against several solid care sources that mostly agree. Numbers here are a careful starting point. Your tap water, tank size, and habits decide the rest. How we evaluate.
Best for: Planted community tanks 200L or more where a pair can claim a small territory without displacing neighbours.
Avoid if: You keep cherry shrimp or nano shrimp; keyholes hunt them especially when breeding.
Common mistakeExpecting a keyhole cichlid to compete for food in a busy community is how keepers invent thin, hiding fish that never settle. They are shy feeders. Plan calm neighbours and deliberate feeding — a rowdy barb circus is the wrong home for Cleithracara maronii.
Top things that go wrong
- Mouth gap vs tiny tank mates. May eat tank mates small enough to fit the adult mouth — plan adult sizes, not shop sizes.
- Shrimp & snails. Not shrimp-safe — adults, fry, or both get eaten.
What most shops don't tell you
- 1.Myth: keyhole cichlids thrive as hardy community centrepieces that compete fine with active barbs and tetras. Reality: they are shy feeders that lose condition in high-competition tanks — plan calm neighbours and deliberate feeding, not a busy free-for-all community circus.
- 2.Predation risk scales with gape, night feeding, and crowding. 'they grew up together' is a schedule, not a law.
- 3.Classed peaceful for similar-sized community use. Still a bite-sized risk toward fry or very small comm fish in small volumes.
- 4.Housed in a small tank with larger mixed cichlids. Chronic stress, colour loss, and one back-corner fish.
- 5.Fed a single high-protein pellet with no vegetable or fibre in the rotation.
- 6.Give driftwood and leaf litter for line-of-sight cover. Pair dynamics can swing hard during spawn. Have a rehome or divider plan ready. Skip bite-sized fry in the same tank as adults grow.
About this species
Keyhole cichlids are 10 cm South American shy cichlids with a dark keyhole mark on the flank. They live over leaf litter and roots in soft acidic water. A planted tank with dither fish and bottom cover settles a pair faster than a bare-bottom pair tank.
- Convict cichlid200L min · same group, comparable tank size
- Discus200L min · same group, comparable tank size
- Firemouth Cichlid200L min · same group, comparable tank size
- Rainbow cichlid200L min · same group, comparable tank size
- Angelfish150L min · same fish family
- Electric Blue Acara150L min · same fish family
- Severum250L min · same fish family
- Bolivian Ram110L min · same group, similar adult size
- African freshwater butterflyfishalso intermediate peaceful, similar tank size
- Black ruby barbalso intermediate peaceful, similar tank size
- Boesemani Rainbowfishalso intermediate peaceful, similar tank size
- Bolivian Ramalso intermediate peaceful, similar tank size
- Brown / hockey-stick pencilfishalso intermediate peaceful, similar tank size
- Checkerboard cichlidalso intermediate peaceful, similar tank size
No reverse lookups listed yet.
Plan grid
Key limits are above. Here: pH band, swim level, bioload, and activity.
Swim zones
Care snapshot
Quick compare before you buy. Not a score of how “good” the fish is.
- Beginner ease50
- Peacefulness68
- Community fit52
- Small-tank fit90
- Hardiness54
- Energy54
Numbers are deterministic planning indices from Fishori fields — not a scientific score of your individual fish.
Example setups
Starting points only. Run the pair checker for every fish you add.
Avoid “one of everything” baskets — Keyhole cichlid belongs in a plan built around territory, line-of-sight breaks, and matched water chemistry.
Compatibility
Tank mates for Keyhole cichlid
Usually safer (engine GOOD): Dwarf Gourami. Conditional (CAUTION — read the pair page before buying): Angelfish, Boesemani Rainbowfish, Corydoras Catfish, Electric Blue Acara, Neon Tetra. Avoid (RISKY): African Cichlid, Jack Dempsey, Oscar. Every name links to a live pair check — the lists are a shortlist, not a stocking plan.
Usually safer
Open a pair page with this fish as the starting point.
Needs planning
Read the blocking rule on each pair page before experimenting.
Usually avoid
Do-not-stock combinations on conservative hobby rules.
Compare with
Run a real pair check: Keyhole cichlid + Dwarf Gourami
- Try Dwarf Gourami — open the pair check.
Behaviour and temperament
Keyhole cichlids are relatively peaceful for cichlids but stay shy and can defend a nest when spawning. They need calm company and room. Stress shows as hiding and weight loss when boisterous fish outcompete them at every feed in a short busy tank.
What sets them off
- Sudden crowding
- Poor water quality
Fin nipping: Not a habitual fin-nipper; stressed or crowded individuals can still test fins.
Predation: May eat tank mates small enough to fit the adult mouth — plan adult sizes, not shop sizes.
Territory: Holds a patch (cave, corner, or surface). Break sight lines so neighbours can pass.
Planted tanks: excellent — easy plant ideas
In the glass: typical and warning signs
- A pair holds mid-to-bottom cover in a calm planted South American layout.
- Gentle browsing and cautious approaches to food are normal ownership.
- Chronic hiding at feeding time usually means competition failed first.
- Thin flanks in a barb tank mean neighbour choice failed before mystery disease.
- Low malice toward robust peaceful fish outside spawn defence.
- Spawn periods can still see corner defence against dither in tight tanks.
- Remove hyper feeders before adding another shy centrepiece.
- Feed after lights soften so the pair reaches food without a stampede.
Fish behaviour can vary between individuals and tank setups. Always observe new fish closely after introduction.
Water, food, and grouping
Hardness
soft
Diet
omnivore
Keyhole cichlids are shy omnivores that take quality pellets, frozen foods, and sinking items when competition is low. In a frantic community they lose every feed and fade. Offer food after lights soften in a calm two-hundred-litre class layout, and never assume busy midwater fish leave them enough to eat.
Shrimp & snails
Not shrimp-safe — adults, fry, or both get eaten.
Keep at least 2, bought at the same time.
- Hold 24 to 30 °C steadily on a real thermometer, not the dial on the heater.
- Aim for pH 6 to 7.5 and a hardness you can re-test in two weeks. A one-time strip in the shop car park is not a water test.
- Footprint: short wide tanks and tall narrow tanks fish differently for the same volume. Match the tank shape to the swim pattern, not just the litre count.
- Tank volume meets or exceeds 200L published minimum for adults.
- You can stock at least 2 individuals (group welfare).
- Heater can hold 24–30°C without cooking cooler-water tank mates.
- No tank mates small enough to fit the adult mouth gap for this species.
Explore and stocking hubs
Tank-mates hub, matching guides, category peers, and litre stocking lists around this species’ minimum tank.
Plan with tools
Check mates as pairs first, then add this fish in the tank builder for the full stocking.
Filtration & heating
A 200L minimum tank needs a filter rated for at least 800L/hr turnover and a heater to hold 24–30°C reliably.
Plant suggestions
Keyhole cichlid does well in planted tanks. Plants compatible with 24–30°C and pH 6–7.5:
Research: partially verified · Confidence: high · 3 linked source(s). We do not invent citations.
How Fishori evaluates compatibility (same logic as pair and tank tools).
- Seriously Fish. Cleithracara maronii
Primary: aquarium size, water chemistry, behaviour, and compatibility (URL verified in upgrade script; recheck if site content changes).
- FishBase. Cleithracara maronii
Secondary: taxonomy, distribution, and maximum length in nature; cross-check with aquarium import lines and measured tank parameters.
- Wikipedia. Cleithracara maronii
Secondary: general species context; verify all husbandry numbers against a dedicated aquarium care sheet and your test kit, not a single table row.
Evidence notes
- The Seriously Fish profile for the binomial in this record was successfully reached as the primary aquarium reference.
- FishBase contributes natural-range size and habitat context. Translate those numbers through your heater, your water report, and your tank footprint before stocking.
- Wikipedia is only cited if the article URL returned OK. Use it for orientation, not as the only care sheet for an import.
- All compatibility text reflects typical hobby experience and the Fishori model. Individual fish, shop stress, and the order tank mates are added in can still defy a single-paragraph label.
Common questions about Keyhole cichlid
- How big do Keyhole cichlid get?
- Keyhole cichlid adults reach about 10 cm. Shop fish look smaller; stock for the adult length.
- What size tank does Keyhole cichlid need?
- 200L is the planning floor for adult swimming space and bioload. A 244L+ tank is the more comfortable long-term footprint. Length and depth matter as much as raw litres for active or territorial fish.
- Are Keyhole cichlid aggressive?
- Keyhole cichlids are relatively peaceful for cichlids but stay shy and can defend a nest when spawning. They need calm company and room. Stress shows as hiding and weight loss when boisterous fish outcompete them at every feed in a short busy tank.
- What is the most common mistake with Keyhole cichlid?
- Expecting a keyhole cichlid to compete for food in a busy community is how keepers invent thin, hiding fish that never settle. They are shy feeders. Plan calm neighbours and deliberate feeding — a rowdy barb circus is the wrong home for Cleithracara maronii.
- What fish can live with Keyhole cichlid?
- The Keyhole cichlid profile lists Dwarf Gourami among its safer pairings (engine-checked GOOD). Angelfish, Boesemani Rainbowfish, Corydoras Catfish, Electric Blue Acara are conditional (CAUTION): workable only with the specific conditions on each pair page. Avoid African Cichlid, Jack Dempsey, Oscar (RISKY). Run the pair checker for your exact water and tank size before stocking.