Paradise fish
Macropodus opercularis
intermediate careOverview
The paradise fish (Macropodus opercularis) is a striking, hardy labyrinth fish — one of the first tropical fish ever kept in the hobby. Banded in electric blue and red, it is beautiful, tough and unusually cool-tolerant, but also decidedly aggressive. That temperament, and the care needed in choosing tankmates, make it an intermediate fish despite how easy it is to keep alive. Given the right setup, it is a bold, long-lived centrepiece.
Tank & water
Paradise fish are adaptable and cool-tolerant, but their attitude means space and cover matter. Aim for at least 75 litres (20 gallons).
- Temperature: 16–26 °C; they tolerate cool water and can live unheated in a warm room, though a heater keeps things stable.
- Filtration & flow: a gentle filter is best; as a labyrinth fish it breathes at the surface, so keep flow soft and leave an air gap under a secure lid — they jump.
- Water: very adaptable across pH 6.0–8.0 and a wide hardness range.
- Planting: dense plants and hardscape break sightlines and reduce aggression.
Feeding
Paradise fish are enthusiastic omnivores and even micro-predators. Feed a quality flake or pellet once or twice a day, with plenty of frozen or live foods — bloodworm, daphnia, brine shrimp, mosquito larvae — which they relish. They also hunt small pest snails and insect larvae. Feed only what they finish quickly; see best fish food.
Tankmates
Best kept as a single specimen or with fast, robust fish that can stay out of its way: larger active barbs, danios and sturdy catfish. Avoid other paradise fish (males fight), bettas, and slow or long-finned species that trigger aggression.
Common care notes
- Aggressive — keep one male or a matched pair
- Tolerates cool water; secure lid essential for jumpers
- Provide dense cover to break sightlines
- Choose fast, robust tankmates only
Hardy, cool-tolerant and long-lived, the paradise fish rewards keepers who respect its temperament with years of bold colour and character.
Paradise fish — frequently asked questions
Can paradise fish live in an unheated tank?
Often, yes. Paradise fish are one of the few tropical-looking labyrinth fish that tolerate cool water, roughly 16–26 °C, and can live unheated in a warm room. Stable temperature still matters, and sudden chills should be avoided.
Are paradise fish aggressive?
Yes — notably so. Males are territorial and combative toward other paradise fish and long-finned or similar-looking species. Keep a single male, or a carefully matched pair, and choose robust, fast tankmates.
Do paradise fish need a heater and lid?
A lid, always — as labyrinth fish they breathe at the surface and will jump. A heater is optional in a warm room given their cool tolerance, but it keeps temperature stable, which they still appreciate.
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