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Paradise Fish (Macropodus opercularis)
One of the first ornamental fish ever kept by hobbyists — a tough, labyrinth-breathing beauty that thrives in an unheated room-temperature tank, provided you keep just one male.
Will it live with a Paradise Fish?
We compare each fish against your paradise fish on temperament, size, water parameters and swimming zone. Set your tank size and filter the results.
- Agassiz's Corydoras✅ CompatiblePeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 22–26 °C — no size, zone or temperament conflicts.
- Keep Agassiz's Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Banjo Catfish✅ CompatiblePeaceful · 15 cm · Medium care · 20–26 °C (68–79 °F)
- Compatible on the things that matter: shared water near 20–26 °C, workable temperaments, and no predator-and-prey size gap.
- Bearded Corydoras✅ CompatiblePeaceful · 10 cm · Medium care · 18–24 °C (64–75 °F)
- Compatible on the things that matter: shared water near 18–24 °C, workable temperaments, and no predator-and-prey size gap.
- 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)
- Compatible on the things that matter: shared water near 23–26 °C, workable temperaments, and no predator-and-prey size gap.
- Blood Red Tiger Pleco✅ CompatiblePeaceful · 6 cm · Medium care · 24–29 °C (75–84 °F)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
- Bolivian Ram✅ CompatiblePeaceful · 8 cm · Medium care · 24–28 °C (75–82 °F)
- Aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Burmese Loach✅ CompatiblePeaceful · 9 cm · Easy care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 22–26 °C, workable temperaments, and no predator-and-prey size gap.
- Butterfly Hillstream Loach✅ CompatiblePeaceful · 6 cm · Hard care · 18–24 °C (64–75 °F)
- Aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Clown Pleco✅ CompatiblePeaceful · 9 cm · Medium care · 24–28 °C (75–82 °F)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
- Corydoras Catfish✅ CompatiblePeaceful · 6.5 cm · Easy care · 22–26 °C (72–79 °F)
- Aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Corydoras Catfish in a shoal of 6+ or it gets stressed and nippy.
- Dwarf Chain Loach✅ CompatiblePeaceful · 6 cm · Medium care · 24–29 °C (75–84 °F)
- Aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Dwarf Chain Loach 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)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
- Kuhli Loach✅ CompatiblePeaceful · 10 cm · Easy care · 24–30 °C (75–86 °F)
- Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
- Leopard Frog Pleco✅ CompatiblePeaceful · 9 cm · Medium care · 25–30 °C (77–86 °F)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 25–26 °C — no size, zone or temperament conflicts.
- Marbled Hoplo✅ CompatiblePeaceful · 14 cm · Easy care · 22–28 °C (72–82 °F)
- Aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Murray River Rainbowfish✅ CompatiblePeaceful · 11 cm · Easy care · 15–26 °C (59–79 °F)
- Aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Murray River Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Peppered Corydoras✅ CompatiblePeaceful · 7 cm · Easy care · 18–26 °C (64–79 °F)
- Compatible on the things that matter: shared water near 18–26 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Peppered Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Porthole Catfish✅ CompatiblePeaceful · 10 cm · Easy care · 22–28 °C (72–82 °F)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 22–26 °C — no size, zone or temperament conflicts.
- Rio Negro Checkerboard Cichlid✅ CompatiblePeaceful · 7 cm · Hard care · 24–29 °C (75–84 °F)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–26 °C — no size, zone or temperament conflicts.
- Spotfin Corydoras✅ CompatiblePeaceful · 6.5 cm · Easy care · 22–26 °C (72–79 °F)
- Aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Spotfin Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Spotted Corydoras✅ CompatiblePeaceful · 7 cm · Easy care · 22–27 °C (72–81 °F)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 22–26 °C — no size, zone or temperament conflicts.
- Keep Spotted Corydoras 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)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 20–26 °C — no size, zone or temperament conflicts.
- Sterbai Corydoras✅ CompatiblePeaceful · 6.5 cm · Medium care · 24–30 °C (75–86 °F)
- Compatible on the things that matter: shared water near 24–26 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Sterbai Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Zebra Pleco✅ CompatiblePeaceful · 10 cm · Hard care · 26–30 °C (79–86 °F)
- Compatible on the things that matter: shared water near 26–26 °C, workable temperaments, and no predator-and-prey size gap.
- Boesemani Rainbowfish⚠️ With cautionPeaceful · 11 cm · Medium care · 24–28 °C (75–82 °F)
- Your 80 L tank is below the ~115 L this pairing really wants — crowding raises aggression.
- Keep Boesemani Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Brilliant Rasbora⚠️ With cautionPeaceful · 9 cm · Easy care · 22–28 °C (72–82 °F)
- Paradise Fish is aggressive and may chase or nip the smaller Brilliant Rasbora — plant heavily and break up sight lines.
- Keep Brilliant Rasbora in a shoal of 6+ or it gets stressed and nippy.
- Bristlenose Pleco⚠️ With cautionPeaceful · 12 cm · Easy care · 23–30 °C (73–86 °F)
- Your 80 L tank is below the ~95 L this pairing really wants — crowding raises aggression.
- Clown Rasbora⚠️ With cautionPeaceful · 10 cm · Medium care · 23–28 °C (73–82 °F)
- Paradise Fish and Clown Rasbora are close in size, but the aggressive one tends to dominate — add clown rasbora in a group to spread the pressure.
- 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.
- Giant Betta⚠️ With cautionPeaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Paradise Fish and Giant Betta are both labyrinth fish and often treat each other as rivals — give a large, broken-up tank and be ready to separate them.
- Giant Danio⚠️ With cautionPeaceful · 10 cm · Easy care · 20–27 °C (68–81 °F)
- Expect Paradise Fish to harass Giant Danio at times; give dense cover and watch them at feeding.
- 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.
- Keyhole Cichlid⚠️ With cautionPeaceful · 10 cm · Easy care · 22–28 °C (72–82 °F)
- Expect Paradise Fish to harass Keyhole Cichlid at times; give dense cover and watch them at feeding.
- Mascara Barb⚠️ With cautionPeaceful · 12 cm · Medium care · 20–25 °C (68–77 °F)
- Your 80 L tank is below the ~200 L this pairing really wants — crowding raises aggression.
- Keep Mascara Barb in a shoal of 8+ or it gets stressed and nippy.
- Medusa Pleco⚠️ With cautionPeaceful · 12 cm · Medium care · 26–30 °C (79–86 °F)
- Your 80 L tank is below the ~115 L this pairing really wants — crowding raises aggression.
- Molly⚠️ With cautionPeaceful · 10 cm · Easy care · 23–28 °C (73–82 °F)
- Expect Paradise Fish to harass Molly at times; give dense cover and watch them at feeding.
- Pearl Gourami⚠️ With cautionPeaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Paradise Fish and Pearl Gourami are both labyrinth fish and often treat each other as rivals — give a large, broken-up tank and be ready to separate them.
- Your 80 L tank is below the ~115 L this pairing really wants — crowding raises aggression.
- Rubber Lip Pleco⚠️ With cautionPeaceful · 12 cm · Easy care · 20–26 °C (68–79 °F)
- Your 80 L tank is below the ~115 L this pairing really wants — crowding raises aggression.
- Silver Tetra⚠️ With cautionPeaceful · 9 cm · Easy care · 24–28 °C (75–82 °F)
- Paradise Fish is aggressive and may chase or nip the smaller Silver Tetra — plant heavily and break up sight lines.
- Your 80 L tank is below the ~115 L this pairing really wants — crowding raises aggression.
- Keep Silver Tetra in a shoal of 6+ or it gets stressed and nippy.
- Thick-lipped Gourami⚠️ With cautionPeaceful · 9 cm · Easy care · 22–28 °C (72–82 °F)
- Paradise Fish and Thick-lipped Gourami are close in size, but the aggressive one tends to dominate — add thick-lipped gourami in a group to spread the pressure.
- Paradise Fish and Thick-lipped Gourami are both labyrinth fish and often treat each other as rivals — give a large, broken-up tank and be ready to separate them.
- 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.
- Zebra Loach⚠️ With cautionPeaceful · 9 cm · Medium care · 23–26 °C (73–79 °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)
- Paradise Fish and Alligator Gar are both territorial and at least one is outright aggressive — expect serious fighting.
- Paradise Fish is bite-sized to a 250 cm predatory alligator gar — it will be eaten.
- 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)
- Two assertive fish, one genuinely aggressive: Paradise Fish and Clown Knifefish will hold territory and clash.
- Clown Knifefish (90 cm) is big enough to swallow the 10 cm Paradise Fish whole.
- 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)
- Two assertive fish, one genuinely aggressive: Paradise Fish and Fire Eel will hold territory and clash.
- Paradise Fish is bite-sized to a 100 cm predatory fire eel — it will be eaten.
- 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)
- Koi (90 cm) is big enough to swallow the 10 cm Paradise Fish whole.
- Your 80 L tank is below the ~3800 L this pairing really wants — crowding raises aggression.
- Mekong Giant Catfish⛔ Not recommendedSemi-aggressive · 300 cm · Hard care · 20–28 °C (68–82 °F)
- Paradise Fish and Mekong Giant Catfish are both territorial and at least one is outright aggressive — expect serious fighting.
- Your 80 L tank is below the ~100000 L this pairing really wants — crowding raises aggression.
- Redtail Catfish⛔ Not recommendedAggressive · 120 cm · Hard care · 24–27 °C (75–81 °F)
- Paradise Fish and Redtail Catfish are both territorial and at least one is outright aggressive — expect serious fighting.
- Redtail Catfish (120 cm) is big enough to swallow the 10 cm Paradise Fish whole.
- 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)
- Paradise Fish and Spotted Gar are both territorial and at least one is outright aggressive — expect serious fighting.
- Paradise Fish is bite-sized to a 90 cm predatory spotted gar — it will be eaten.
- 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)
- Paradise Fish and Wels Catfish are both territorial and at least one is outright aggressive — expect serious fighting.
- Size gap is too large (300 vs 10 cm): Wels Catfish will treat Paradise Fish as food.
- Your 80 L tank is below the ~20000 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.
Paradise Fish care specs
- Care level
- Medium
- Breeding
- Medium
- Max size
- 10 cm (3.9 in)
- Min tank size
- 80 L (21.1 gal)
- Temperature
- 16–26 °C (61–79 °F)
- pH
- 6–8
- Hardness
- 4–20 dGH
- Lifespan
- 5–7 years
- Diet
- Omnivore
- Swim level
- Top
- Group size
- Best alone or in a pair
- Family
- Osphronemidae
- Origin
- East Asia — southern China, Vietnam, Taiwan and the Korean Peninsula; rice paddies, ponds and sluggish streams
What is a Paradise Fish?
The paradise fish (Macropodus opercularis) is one of the oldest ornamental fish in the hobby, imported to France as early as 1869 — decades before most tropical fish reached European aquarists. Its longevity in the trade is no accident: this is a genuinely tough, adaptable fish that breathes atmospheric air through a labyrinth organ, tolerates an unusually wide temperature range, and handles water quality that would stress more delicate species.
Adults grow to around 10 cm (4 in) and are anything but plain. Males in particular display vivid alternating bands of electric blue and red-orange across the body and into the fins, with trailing extensions on the caudal and anal fins that rival any fancy gourami. Selectively bred colour forms — red, albino, and blue morph variants — are also available. The beauty comes with a temperament to match: paradise fish are aggressive and best kept by fishkeepers who plan their community carefully rather than newcomers looking for an easy community centrepiece.
Where do Paradise Fish come from?
Wild paradise fish range across East Asia — southern China, Vietnam, Taiwan and the Korean Peninsula. Their natural habitats are slow-moving or still waters: rice paddies, roadside ditches, shallow ponds, irrigation channels and sluggish streams with dense emergent vegetation. These environments can fluctuate dramatically in temperature with the seasons, which explains the species’ remarkable tolerance of cool water.
Water in these habitats is often soft to moderately hard and ranges from slightly acidic to mildly alkaline — matching the wide pH tolerance (6.0–8.0) and hardness range (4–20 dGH) reflected in the quick-facts. Understanding this origin helps explain both their hardiness and their belligerence: in a seasonally variable, resource-contested environment, aggression is a survival trait.
What size tank does a Paradise Fish need?
The minimum recommended tank size is 80 litres (21 gallons). A single male can be kept in this footprint provided the tank is well-planted and broken into visual zones with decor. A larger tank — 100–150 L (26–40 gal) — gives you more flexibility if you want to keep a male-female pair or include robust tankmates.
Footprint matters more than height. Paradise fish are top-dwelling labyrinth fish that regularly surface to breathe air; they need unobstructed access to the water surface, and they also need to swim horizontal territory. A long, shallower tank beats a tall narrow column. Keep a tight-fitting lid — paradise fish are strong jumpers, and surface access combined with curiosity makes escapes a real risk. Flow from the filter should be gentle; these fish come from still water and do not thrive in a strong current.
What water parameters do Paradise Fish need?
- Temperature: 16–26 °C (61–79 °F). No heater required in most temperate homes, but avoid drops below 15 °C and sudden swings.
- pH: 6.0–8.0. One of the widest acceptable ranges in the hobby — dechlorinated tap water usually falls right in without adjustment.
- Hardness: 4–20 dGH. Soft to hard water is tolerated equally well.
The headline parameter for paradise fish is temperature. Most tropical community fish need 24–28 °C, so paradise fish are unusual in thriving at room temperature — a meaningful practical advantage if you want an unheated display tank. That said, stability still matters: rapid temperature swings weaken the immune system just as they do for any fish. Keep up with regular water changes and make sure the nitrogen cycle is established before adding the fish.
What do Paradise Fish eat?
Paradise fish are omnivores with a strong preference for meaty foods. In the wild they take insects, larvae, small crustaceans and plant matter. In the aquarium, offer a quality flake or small pellet as a daily staple and rotate in frozen or live foods several times a week — bloodworm, daphnia, brine shrimp and mosquito larvae are all accepted eagerly and enhance colour and condition.
Feed small amounts once or twice daily, only what the fish consumes in two to three minutes. Paradise fish are enthusiastic feeders but leftover food degrades water quality quickly in a smaller tank. A fasting day once per week helps prevent obesity and keeps digestion healthy. Surface-feeding pellets or floating flakes suit their top-dwelling nature well.
Are Paradise Fish aggressive — and what fish can live with them?
Yes — aggressive is an accurate label and should be taken seriously when planning a community. Males are highly territorial toward one another and will fight to the point of severe injury or death if housed together. A single male per tank is the firm rule. Males may also harass females relentlessly outside of breeding conditions, so any male-female pairing needs heavy planting and visual breaks, and the female should be removed after spawning.
Beyond conspecific aggression, paradise fish will fin-nip slower, long-finned fish and bully anything small enough to intimidate. Good tankmates are robust, fast-moving species that occupy the mid or lower zones of the tank: larger danios, giant danios, tiger barbs, rainbowfish, weather loaches, or similarly sized robust community fish. Avoid slow, fancy-finned gouramis, bettas, small nano fish, and long-finned varieties of any species. Larger peaceful bottom-dwellers like clown loaches or bristlenose plecos can also work in a sufficiently spacious setup.
For a full, filterable list of compatible and incompatible species, see Paradise Fish tank mates.
How do you tell male and female Paradise Fish apart?
Sexual dimorphism in paradise fish is pronounced and reliable in adults. Males are noticeably larger — approaching the full 10 cm (4 in) — and display the species’ signature coloration most intensely: vivid blue and red-orange banding, brighter overall, with longer and more pointed dorsal and anal fins that trail to elegant extensions. They also build bubble nests at the surface when in breeding condition.
Females are smaller, with a rounder, fuller body particularly noticeable from above when gravid. Their coloration is duller and the fins are shorter and rounded rather than pointed and trailing. Even in juveniles, males tend to show more intense coloration and longer fin development as they mature from around 4–5 cm onward.
How do Paradise Fish breed?
Paradise fish are bubble-nest builders, sharing this breeding strategy with bettas and gouramis. When conditioned on live or frozen foods and provided with warmer water (upper end of their range, around 24–26 °C / 75–79 °F), the male will construct a nest of bubbles at the surface — often anchored under a floating plant or at the edge of the tank.
Courtship involves the male displaying and chasing the female. If she is receptive, spawning follows the familiar labyrinth-fish pattern: the male wraps his body around the female in an embrace, fertilising eggs as they are released. He then collects the sinking eggs and places them in the bubble nest, repeating the process multiple times. After spawning, remove the female — the male will guard the nest aggressively and may injure or kill her if left together. The male tends the nest, retrieving fallen eggs and maintaining the bubble structure until the fry are free-swimming, typically within three to five days at warmer temperatures.
We rate breeding medium difficulty — the fish will usually attempt to spawn given basic conditioning, but raising fry requires small live foods (infusoria, baby brine shrimp) and separating the male once fry are free-swimming.
What are common Paradise Fish diseases?
Paradise fish are hardier than most aquarium species, but they are not immune to the usual freshwater disease pressures.
Ich (white spot disease) can appear after a sudden temperature drop or when a new fish introduces the pathogen — watch for small white dots on the body and fins. Velvet (Oodinium) presents as a dusty golden or rust-coloured sheen and is particularly dangerous in labyrinth fish. Fin rot — ragged, discoloured fin edges — is almost always a water-quality problem and resolves with improved husbandry before medication is needed. Bacterial infections can follow fin damage from fighting, so monitor any fish after a territorial dispute.
Prevention is straightforward: maintain stable water parameters and temperature, perform regular water changes, quarantine new fish for at least two weeks before adding them to the main tank, and avoid the stress of incompatible tankmates. A healthy paradise fish in clean water is remarkably resistant to disease.
Health note: disease diagnosis and medication selection go beyond the scope of a care profile. If your fish show signs of illness, confirm the diagnosis against a reputable veterinary or fish-health source before medicating.
How long do Paradise Fish live?
With good care, paradise fish live 5–7 years — a respectable lifespan for a fish of this size and considerably longer than most small community fish. The key to that longevity is straightforward: clean, stable water, a varied diet, a correctly sized tank, and — critically — keeping just one male to eliminate the chronic stress of conspecific aggression. Paradise fish that spend their lives in poor conditions or under constant territorial pressure rarely reach their potential. Give this species a well-planted tank with appropriate tankmates and it will reward you with years of bold, active display.
Frequently asked questions
Can paradise fish live in an unheated aquarium?
Yes — this is one of their standout traits. Macropodus opercularis tolerates 16–26 °C, so a room-temperature tank in a temperate home is usually fine. Avoid sudden cold snaps below 15 °C, but you genuinely do not need a heater for this species in most climates.
Why can't I keep two male paradise fish together?
Males are highly territorial and will fight relentlessly, often to the death. Keep only one male per tank. A male-female pair works in 80 L or more with plenty of cover, or a single male alongside peaceful, robust tankmates that can handle a bit of fin-nipping.
What you need to keep a paradise fish
The baseline is a heated, filtered 80 L+ tank: a reliable heater to hold 16–26 °C (61–79 °F), a gentle filter that won't batter a paradise fish in the current, and a tight-fitting lid. Cycle the tank fully before adding any fish.
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