Photo: User:Haplochromis (CC BY-SA 3.0) — via Wikimedia Commons
Moonlight Gourami (Trichogaster microlepis)
A large, silver-scaled labyrinth fish with an almost metallic sheen — serene, graceful, and one of the few big gouramis that stays genuinely peaceful.
Will it live with a Moonlight Gourami?
We compare each fish against your moonlight gourami on temperament, size, water parameters and swimming zone. Set your tank size and filter the results.
- Banjo Catfish✅ CompatiblePeaceful · 15 cm · Medium care · 20–26 °C (68–79 °F)
- Compatible on the things that matter: shared water near 25–26 °C, workable temperaments, and no predator-and-prey size gap.
- Boesemani Rainbowfish✅ CompatiblePeaceful · 11 cm · Medium care · 24–28 °C (75–82 °F)
- Both are peaceful, and their water overlaps around 25–28 °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 Boesemani Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Bristlenose Pleco✅ CompatiblePeaceful · 12 cm · Easy care · 23–30 °C (73–86 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Clown Rasbora✅ CompatiblePeaceful · 10 cm · Medium care · 23–28 °C (73–82 °F)
- Both are peaceful, and their water overlaps around 25–28 °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 Clown Rasbora in a shoal of 6+ or it gets stressed and nippy.
- Convict Cichlid✅ CompatibleAggressive · 10 cm · Easy care · 21–28 °C (70–82 °F)
- Peaceful + Aggressive, but with no direct clash here, and their water overlaps around 25–28 °C — no size, zone or temperament conflicts.
- Cupid Cichlid✅ CompatibleSemi-aggressive · 12 cm · Medium care · 24–29 °C (75–84 °F)
- Peaceful + Semi-aggressive, but with no direct clash here, and their water overlaps around 25–29 °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.
- Giant Betta✅ CompatiblePeaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Both are peaceful, and their water overlaps around 25–28 °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.
- Giant Danio✅ CompatiblePeaceful · 10 cm · Easy care · 20–27 °C (68–81 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Giant Danio in a shoal of 6+ or it gets stressed and nippy.
- Giant Kuhli Loach✅ CompatiblePeaceful · 12 cm · Easy care · 24–30 °C (75–86 °F)
- Both are peaceful, and their water overlaps around 25–30 °C — no size, zone or temperament conflicts.
- Golden Wonder Killifish✅ CompatibleSemi-aggressive · 10 cm · Easy care · 22–28 °C (72–82 °F)
- Peaceful + Semi-aggressive, but with no direct clash here, and their water overlaps around 25–28 °C — no size, zone or temperament conflicts.
- Keyhole Cichlid✅ 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.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Kribensis✅ CompatibleSemi-aggressive · 10 cm · Easy care · 24–27 °C (75–81 °F)
- Compatible on the things that matter: shared water near 25–27 °C, workable temperaments, and no predator-and-prey size gap.
- Kuhli Loach✅ CompatiblePeaceful · 10 cm · Easy care · 24–30 °C (75–86 °F)
- Compatible on the things that matter: shared water near 25–30 °C, workable temperaments, and no predator-and-prey size gap.
- Marbled Hoplo✅ CompatiblePeaceful · 14 cm · Easy care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 25–28 °C, workable temperaments, and no predator-and-prey size gap.
- Medusa Pleco✅ CompatiblePeaceful · 12 cm · Medium care · 26–30 °C (79–86 °F)
- Compatible on the things that matter: shared water near 26–30 °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 25–28 °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.
- Pearl Gourami✅ CompatiblePeaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Compatible on the things that matter: shared water near 25–28 °C, workable temperaments, and no predator-and-prey size gap.
- 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.
- Rubber Lip Pleco✅ CompatiblePeaceful · 12 cm · Easy 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.
- Spotted Rubbernose Pleco✅ CompatiblePeaceful · 12 cm · Medium care · 20–26 °C (68–79 °F)
- Compatible on the things that matter: shared water near 25–26 °C, workable temperaments, and no predator-and-prey size gap.
- Spotted Talking Catfish✅ CompatiblePeaceful · 15 cm · Easy care · 22–26 °C (72–79 °F)
- Both are peaceful, and their water overlaps around 25–26 °C — no size, zone or temperament conflicts.
- Striped Eel Loach✅ 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.
- Swordtail✅ CompatibleSemi-aggressive · 14 cm · Easy 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.
- Angelfish⚠️ With cautionSemi-aggressive · 15 cm · Medium care · 24–30 °C (75–86 °F)
- Angelfish is semi-aggressive and may chase or nip the smaller Moonlight Gourami — plant heavily and break up sight lines.
- Blue Flash Cichlid⚠️ With cautionSemi-aggressive · 15 cm · Medium care · 24–28 °C (75–82 °F)
- Blue Flash Cichlid is semi-aggressive and may chase or nip the smaller Moonlight Gourami — plant heavily and break up sight lines.
- Your 115 L tank is below the ~210 L this pairing really wants — crowding raises aggression.
- Bumblebee Cichlid⚠️ With cautionAggressive · 15 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 Bumblebee Cichlid to harass Moonlight Gourami at times; give dense cover and watch them at feeding.
- Your 115 L tank is below the ~200 L this pairing really wants — crowding raises aggression.
- Clown Barb⚠️ With cautionSemi-aggressive · 15 cm · Medium care · 24–30 °C (75–86 °F)
- Clown Barb is semi-aggressive and may chase or nip the smaller Moonlight Gourami — plant heavily and break up sight lines.
- Your 115 L tank is below the ~132 L this pairing really wants — crowding raises aggression.
- Keep Clown Barb in a shoal of 6+ or it gets stressed and nippy.
- Denison Barb⚠️ With cautionPeaceful · 15 cm · Medium care · 18–25 °C (64–77 °F)
- Your 115 L tank is below the ~200 L this pairing really wants — crowding raises aggression.
- Keep Denison Barb in a shoal of 6+ or it gets stressed and nippy.
- Dolphin Cichlid⚠️ With cautionSemi-aggressive · 15 cm · Medium care · 23–28 °C (73–82 °F)
- Expect Dolphin Cichlid to harass Moonlight Gourami at times; give dense cover and watch them at feeding.
- Your 115 L tank is below the ~208 L this pairing really wants — crowding raises aggression.
- Electric Blue Acara⚠️ With cautionSemi-aggressive · 16 cm · Medium care · 22–28 °C (72–82 °F)
- Expect Electric Blue Acara to harass Moonlight Gourami at times; give dense cover and watch them at feeding.
- Emperor Peacock Cichlid⚠️ With cautionSemi-aggressive · 16 cm · Medium care · 24–28 °C (75–82 °F)
- Different pH ranges (6–7.5 vs 7.6–8.6); doable if you sit in the shared band, but not ideal long-term.
- Expect Emperor Peacock Cichlid to harass Moonlight Gourami at times; give dense cover and watch them at feeding.
- Your 115 L tank is below the ~210 L this pairing really wants — crowding raises aggression.
- Eureka Red Peacock Cichlid⚠️ With cautionSemi-aggressive · 15 cm · Medium care · 24–28 °C (75–82 °F)
- pH preferences only just meet (Moonlight Gourami 6–7.5 vs Eureka Red Peacock Cichlid 7.8–8.6) — target the overlap and acclimate slowly.
- Expect Eureka Red Peacock Cichlid to harass Moonlight Gourami at times; give dense cover and watch them at feeding.
- Your 115 L tank is below the ~200 L this pairing really wants — crowding raises aggression.
- Firemouth Cichlid⚠️ With cautionSemi-aggressive · 15 cm · Medium care · 22–29 °C (72–84 °F)
- Expect Firemouth Cichlid to harass Moonlight Gourami at times; give dense cover and watch them at feeding.
- Your 115 L tank is below the ~200 L this pairing really wants — crowding raises aggression.
- Giant Glass Catfish⚠️ With cautionPeaceful · 15 cm · Medium care · 22–27 °C (72–81 °F)
- Your 115 L tank is below the ~120 L this pairing really wants — crowding raises aggression.
- Gold Zebra Loach⚠️ With cautionSemi-aggressive · 15 cm · Medium care · 25–29 °C (77–84 °F)
- Gold Zebra Loach is semi-aggressive and may chase or nip the smaller Moonlight Gourami — plant heavily and break up sight lines.
- Your 115 L tank is below the ~130 L this pairing really wants — crowding raises aggression.
- Green Phantom Pleco⚠️ With cautionSemi-aggressive · 15 cm · Medium care · 26–30 °C (79–86 °F)
- Green Phantom Pleco is semi-aggressive and may chase or nip the smaller Moonlight Gourami — plant heavily and break up sight lines.
- Your 115 L tank is below the ~150 L this pairing really wants — crowding raises aggression.
- Jewel Cichlid⚠️ With cautionAggressive · 15 cm · Medium care · 22–26 °C (72–79 °F)
- Jewel Cichlid and Moonlight Gourami are close in size, but the aggressive one tends to dominate — add moonlight gourami in a group to spread the pressure.
- Your 115 L tank is below the ~150 L this pairing really wants — crowding raises aggression.
- Panama Convict Cichlid⚠️ With cautionAggressive · 15 cm · Medium care · 24–30 °C (75–86 °F)
- Panama Convict Cichlid and Moonlight Gourami are close in size, but the aggressive one tends to dominate — add moonlight gourami in a group to spread the pressure.
- Your 115 L tank is below the ~150 L this pairing really wants — crowding raises aggression.
- Yoyo Loach⚠️ With cautionSemi-aggressive · 15 cm · Medium care · 24–30 °C (75–86 °F)
- Yoyo Loach and Moonlight Gourami are close in size, but the semi-aggressive one tends to dominate — add moonlight gourami in a group to spread the pressure.
- Alligator Gar⛔ Not recommendedAggressive · 250 cm · Hard care · 24–28 °C (75–82 °F)
- Alligator Gar (250 cm) is big enough to swallow the 15 cm Moonlight Gourami whole.
- Alligator Gar clearly outsizes Moonlight Gourami and is aggressive; risky unless the tank is big and well-planted.
- Your 115 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)
- Clown Knifefish (90 cm) is big enough to swallow the 15 cm Moonlight Gourami whole.
- Clown Knifefish is aggressive and may chase or nip the smaller Moonlight Gourami — plant heavily and break up sight lines.
- Your 115 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)
- Size gap is too large (100 vs 15 cm): Fire Eel will treat Moonlight Gourami as food.
- Expect Fire Eel to harass Moonlight Gourami at times; give dense cover and watch them at feeding.
- Your 115 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)
- Koi (90 cm) is big enough to swallow the 15 cm Moonlight Gourami whole.
- Your 115 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)
- Moonlight Gourami is bite-sized to a 120 cm predatory redtail catfish — it will be eaten.
- Redtail Catfish clearly outsizes Moonlight Gourami and is aggressive; risky unless the tank is big and well-planted.
- Your 115 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)
- Spotted Gar (90 cm) is big enough to swallow the 15 cm Moonlight Gourami whole.
- Spotted Gar clearly outsizes Moonlight Gourami and is aggressive; risky unless the tank is big and well-planted.
- Your 115 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)
- Moonlight Gourami is bite-sized to a 300 cm predatory wels catfish — it will be eaten.
- Wels Catfish is aggressive and may chase or nip the smaller Moonlight Gourami — plant heavily and break up sight lines.
- Your 115 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)
- Wolf Cichlid (72 cm) is big enough to swallow the 15 cm Moonlight Gourami whole.
- Wolf Cichlid is aggressive and may chase or nip the smaller Moonlight Gourami — plant heavily and break up sight lines.
- Your 115 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.
Moonlight Gourami care specs
- Care level
- Easy
- Breeding
- Medium
- Max size
- 15 cm (5.9 in)
- Min tank size
- 115 L (30.4 gal)
- Temperature
- 25–30 °C (77–86 °F)
- pH
- 6–7.5
- Hardness
- 2–12 dGH
- Lifespan
- 4–7 years
- Diet
- Omnivore
- Swim level
- Middle
- Group size
- Best alone or in a pair
- Family
- Osphronemidae
- Origin
- Southeast Asia — Thailand, Cambodia, and the lower Mekong basin
What is a Moonlight Gourami?
The Moonlight Gourami (Trichogaster microlepis) is a large, gentle labyrinth fish native to lowland rivers and floodplains across Southeast Asia. Adults reach up to 15 cm (6 in) and carry a quietly striking appearance: the body is covered in tiny, fine scales — microlepis means “small-scaled” — that reflect light with a cool, silvery-green iridescence. The long, filamentous pelvic fins glow orange-red in males and yellow-orange in females.
Unlike many fish that reach this size, the Moonlight Gourami earns a genuine reputation for peaceful behaviour. It belongs to the family Osphronemidae and is a close relative of the betta, but it lacks the territorial aggression of its smaller cousin. For aquarists wanting a large, graceful centrepiece that coexists with a community rather than dominating it, this species is one of the better choices available.
As a labyrinth fish it possesses an accessory breathing organ that lets it take in atmospheric air at the surface — an adaptation that is essential rather than optional. The fish must be able to reach the surface freely at all times.
Where does the Moonlight Gourami come from?
Moonlight Gouramis originate from Southeast Asia, specifically Thailand, Cambodia, and the lower Mekong basin. In the wild they inhabit slow-moving or standing bodies of water: lowland rivers, floodplain lakes, swamps, and rice paddies where the current is minimal and vegetation is dense. These environments are typically warm, soft, and slightly acidic — conditions shaped by tropical rainfall and organic matter from surrounding forests and agricultural land.
This origin matters directly for captive care: the Moonlight Gourami has not evolved for strong flow, bright open spaces, or hard alkaline water. Mimicking the warm, still, heavily planted character of its native habitat is the most reliable way to keep it healthy and confident.
What size tank does a Moonlight Gourami need?
The minimum practical tank size for a single Moonlight Gourami is 115 litres (30 gallons). At 15 cm (6 in) this is a large fish, and for a pair or a community that includes this species, 200 litres (53 gallons) or more is a much better target.
Choose a long, low-profile tank rather than a tall column — the fish spends most of its time in the middle of the water column and needs unobstructed access to the surface for air-breathing. A fitted lid helps prevent jumping, which gouramis can do when startled.
Decorate with dense planting along the sides and back using taller stem plants and broad-leafed species such as Amazon sword. Floating plants like water sprite or frogbit diffuse surface light, break lines of sight, and create the shaded, calm character that matches the Moonlight Gourami’s lowland wetland origins. Leave clear swimming lanes through the middle.
What water parameters does the Moonlight Gourami need?
- Temperature: 25–30 °C (77–86 °F). This is a warm-water species; the lower end of the range is suitable for a mixed community, while the upper end promotes breeding activity.
- pH: 6.0–7.5. Soft to neutral water replicates the Mekong lowlands. Hard alkaline water outside this range stresses the fish over time.
- Hardness: 2–12 dGH. The species is native to soft water and does best toward the softer end; it tolerates moderate hardness well enough for most community setups.
Keep flow gentle. A sponge filter or hang-on filter returning water along the back wall without strong surface agitation is ideal. Heavy surface turbulence disrupts the calm the fish relies on for air-breathing. Perform weekly partial water changes of 20–30 % to maintain stability; consistent water quality prevents the slow drift toward poor conditions that catches out inattentive keepers.
What does a Moonlight Gourami eat?
Moonlight Gouramis are omnivores with a straightforward appetite. A quality flake or small pellet forms a reliable staple; supplement two or three times a week with frozen or live foods — bloodworms, daphnia, brine shrimp, and mosquito larvae are all taken readily and noticeably improve colour and condition.
Feed once or twice a day in small amounts the fish can consume within two or three minutes. Overfeeding degrades water quality quickly and can cause digestive issues. This species will also graze on soft-leaved plants and pick at biofilm on décor, which is normal and harmless.
Is the Moonlight Gourami peaceful — and what fish can live with it?
The Moonlight Gourami is genuinely peaceful for its size. It will not harass tank-mates, does not fin-nip, and retreats rather than confronts. The one consistent exception is male-to-male interaction: two males in a smaller tank may spar, especially in breeding condition. The solution is to keep one male, or provide a large, heavily planted tank with clear visual separation.
Good tank-mates include mid-sized tetras such as Congo tetras and larger rasboras, corydoras catfish, peaceful loaches, and other non-aggressive gouramis of similar size. Avoid fin-nippers like tiger barbs and aggressive cichlids that will stress or injure this calm species.
For a curated, filterable list of pairings, see Moonlight Gourami tank mates.
How do you tell male from female Moonlight Gouramis?
Sexual dimorphism in Moonlight Gouramis is subtle but consistent once you know what to look for. The most reliable indicator is pelvic fin colour: males have distinctly red-orange pelvic fins, while females have yellow-orange pelvic fins that are noticeably less vivid. In practice, placing a male and female side by side makes the colour difference apparent immediately.
Body shape provides a secondary clue. Mature females develop a fuller, rounder belly — particularly visible from above — which reflects their carrying capacity for eggs. Males may also show slightly more intense overall silvery colouring during breeding condition, though the difference is not as marked as in more sexually dimorphic species.
Sexing juveniles is difficult — wait until the fish are close to adult size before attempting.
How do Moonlight Gouramis breed?
Moonlight Gouramis are bubble-nest builders, and breeding them in a home aquarium is achievable with patience and the right setup. We rate it medium difficulty. The male constructs a floating nest of bubbles at the surface, often tucked beneath floating plants or along the edge of the tank. Floating vegetation such as water sprite or frogbit provides both the material and the shelter he needs to build an effective nest.
Condition both fish for several weeks with a diet rich in live and frozen foods. Raising the temperature toward 28–30 °C (82–86 °F) and performing a partial water change with slightly cooler water can simulate the onset of the rainy season and trigger spawning behaviour.
When ready, the male wraps around the female in an embrace and fertilises eggs as they fall; he gathers them immediately into the bubble nest. Remove the female after spawning — the male becomes protective and may harass her. He will tend the nest until the fry are free-swimming, at which point remove him too. Fry are tiny; start with infusoria or commercial fry foods, then transition to micro-worms and baby brine shrimp.
What diseases are common in Moonlight Gouramis?
Moonlight Gouramis are hardy, but they share the common freshwater ailments: ich (white spots), velvet (dusty gold or rust-coloured sheen caused by Oodinium), fin rot (ragged fins, almost always a water-quality problem), and occasional internal parasites in recently imported fish. As labyrinth fish, they can also suffer if chilled or kept in excessively turbulent conditions that prevent normal surface air-breathing.
Prevention covers most of this: stable warm water within the stated parameters, regular partial water changes, and a two-to-four week quarantine for any new fish before they join the display tank.
Health note: medication dosing and specific disease diagnosis are beyond the scope of a care profile. For a fish showing symptoms, confirm the condition against a reputable veterinary or aquatic-health reference before treating, and always address water quality as a first step.
How long do Moonlight Gouramis live?
With good husbandry, a Moonlight Gourami typically lives 4–7 years — a worthwhile lifespan for a large community centrepiece. The keys to reaching the upper end of that range are stable water within the stated parameters, a varied diet, a suitably sized tank, and avoiding chronic stressors such as aggression, temperature swings, or neglected water changes. A well-maintained specimen retains its metallic sheen for most of its life.
Frequently asked questions
Is the Moonlight Gourami aggressive toward other fish?
Not typically. Unlike some large gouramis, the Moonlight Gourami is genuinely peaceful and rarely bothers tank-mates. The main exceptions are males kept together in cramped conditions, who may spar; keeping just one male or providing plenty of visual breaks solves the issue.
Why does my Moonlight Gourami come to the surface so often?
Gouramis are labyrinth fish — they breathe atmospheric air through a specialized organ above the gills. Frequent surface visits are completely normal and essential for their health, not a sign that anything is wrong with the water.
What you need to keep a moonlight gourami
The baseline is a heated, filtered 115 L+ tank: a reliable heater to hold 25–30 °C (77–86 °F), a gentle filter that won't batter a moonlight gourami in the current, and a tight-fitting lid. Cycle the tank fully before adding any fish.
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