Home / Fishes / Gouramis, bettas, snakeheads / Round-tailed paradise fish
No federal permit to keepRound-tailed paradise fish
Macropodus ocellatus
Fishes › Gouramis, bettas, snakeheads (Anabantiformes) › Osphronemidae (Gouramis and bettas)
The round-tailed paradise fish (Macropodus ocellatus) is a species of gourami native to eastern Asia, where it is found in Korea and China.
Care at a glance
Species-specific aquarium care
- Tank: At least 24 in long and 12 in front to back for one adult (adults commonly reach about 3.4 in / 8.6 cm).
- Water: Freshwater.
- Temperature: 39–77°F (range recorded for this species).
- pH: 6–7.5.
- Hardness: 5–25 dGH.
- Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
Calculated from this species' own FishBase record: tank size from its typical adult length and swimming zone, water values from its recorded ranges. The group guide below fills in general care.
Care guide
Species care notes
- Tank: a base of at least 31 × 12 in (roughly 19 US gallons); space needed is rated “modest tank”.
- Water: a fairly wide range, from slightly acidic to slightly alkaline, 50–72 °F, pH 6–7.5, 5–20 dGH.
- Behaviour: in a pair; not a community fish.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Can be maintained in a fully-decorated aquarium although many breeders prefer not to use a substrate for ease of maintenance.”
- Diet: “Likely to prey on insect larvae and suchlike in nature, and should be offered small live or frozen Daphnia, Artemia, white worm, grindal worm, etc., in captivity.”
- Tankmates: “Males become territorially aggressive when reproductively active, but this species can be maintained as a group in a suitably-sized, well-decorated aquarium.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Gouramis and labyrinth fish
Applies to most species in this group. Habitat: Warm, still, vegetated waters. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- Planted, calm tanks with floating plants; they breathe air at the surface, so leave a gap under the lid.
Diet
- Food acceptance is species-specific. Parosphromenus deissneri needs tiny live invertebrate foods and commonly refuses dried foods; a pellet/flake staple cannot cover every labyrinth fish.
Health watch
- Males are territorial; dwarf gourami iridovirus.
Understanding the animal
About this animal
About this animal
It is also found in Japan but it is believed that they were introduced from Korea in the 1910s. It is also known to occur in the Amur Basin of Russia, but that is believed to be due to introductions.
Quoted from the Wikipedia article “Round-tailed paradise fish” (CC BY-SA 4.0) 174
In the wild
In the wild
From this species’ own FishBase record (habitat, bottom type, water and breeding data), not its family. Good care copies these conditions.1
| Where it lives | Lives in freshwater. Uses both the bottom and open water. Biology similar to Macropodus opercularis. Reported to be well-adapted to low winter temperatures (4-25°C); adults and juveniles (about 1.5 cm SL), are sometimes active under ice cover (E. Willems pes.comm. 11/12). |
| Water it lives in | Freshwater, 39–77 °F (4–25 °C), pH 6–7.5, hardness 5–25 dH. |
| Climate | Temperate climate. |
What this means for care
- Keep water within its wild range, 39–77 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 84°F (up to 88°F in the hottest sampled areas) |
| Cool-season lows | about 22°F (down to 15°F in the coldest sampled areas) |
| Average temperature | 50–61°F across sampled records |
| Relative humidity | 67–73% on average (driest month about 61%) |
| Rainfall | about 1258 mm a year |
| Winters | Cool to cold winters (lows around 22°F) in much of its native range. Seasonal slowdown may be relevant, but species-specific biology determines whether brumation or hibernation occurs. |
Measured at 108 wild occurrence records sampled against WorldClim 2.1 climate data (1970–2000 averages). Air conditions in the range are ecological context, not enclosure settings: microhabitats such as burrows, leaf litter or basking rocks can be cooler, warmer or more humid.
From the sources
From the sources
Quoted from the matching sections of reputable sources for this exact species. Specialist databases are used first; Wikipedia (community-edited, CC BY-SA 4.0) only fills gaps. Other sources are short credited quotes.
| Overview | The round-tailed paradise fish (Macropodus ocellatus) is a species of gourami native to eastern Asia, where it is found in Korea and China. It is also found in Japan but it is believed that they were introduced from Korea in the 1910s. It is also known to occur in the Amur Basin of Russia, but that is believed to be due to introductions. It inhabits many kinds of freshwater habitats within its range. — Wikipedia (community-edited) |
| Where it lives | Home ranges Population dynamics Growth parameters Max. ages / sizes Length-weight rel. Length-frequencies Mass conversion Recruitment Abundance Life cycle Reproduction Maturity Maturity/Gills rel. — FishBase |
| Appearance and size | The species has a total length of 5–8 cm, making it smaller than the paradise fish (Macropodus opercularis) and the black paradise fish (Macropodus spechti). — Wikipedia (community-edited) |
| Biology | Obligate air-breathing; Biology similar to Macropodus opercularis. Reported to be well-adapted to low winter temperatures (4-25°C); adults and juveniles (about 1.5 cm SL), are sometimes active under ice cover (E. Willems pes.comm. 11/12). — FishBase |
Data and studies
The numbers
The numbers
Each bar is what one source reports. Where several sources weigh in, the dashed gold band marks their average.
Adult length
Maximum recorded length. Measured as total length. Fish in home aquariums often stay smaller than wild records.
Water temperature
Range the species tolerates in nature; aim for the middle.
Minimum tank footprint
Seriously Fish recommends a tank base of at least 31 × 12 in (about 19 US gallons).
Sources for this sheet
- FishBase (Froese & Pauly, eds.), version 24.07 Peer-reviewed researchThe global scientific database on fishes, maintained by a consortium of research institutions; every value is referenced.
- Seriously Fish species profiles Experienced keeper or breederLong-running aquarium reference written and peer-checked by experienced fishkeepers and ichthyologists; each profile covers habitat, tank size, water, diet, behaviour and breeding.
- Merck Veterinary Manual: Management of aquarium fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Merck Veterinary Manual: Types and features of aquatic systems Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Merck Veterinary Manual: Nutritional diseases of fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Seriously Fish — Parosphromenus deissneri Zoo, university or veterinaryAdded in the 2026 source-checked care-guide review.
- Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.
- iNaturalist (captive observations) Community referenceCommunity observation platform run by the California Academy of Sciences and National Geographic; observations marked captive show animals living in homes, zoos and aquariums.
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