Paradise fish

Macropodus opercularis

FreshwaterFish

Care at a glance

Temperature: 50–72°F (10–22°C)
pH: 6.5–7.5
Adult size: 3.1 in (8 cm)
Minimum tank: 25 gal (95 L)
Temperament: Aggressive
Social behavior: Social
Swim level: Middle
Difficulty: Medium
Breeding: Hard
Rarity: Rare
Origin: China, Vietnam, Laos
Family: Osphronemidae

Overview

The paradise fish is a colourful but feisty labyrinth fish. Males are aggressive toward each other and toward similar-shaped fish, so keep a single male, or a group only in a large, well-planted tank with lots of cover and broken sight lines. It occupies the middle and upper water and holds its own with robust, fast tankmates, but it will bully timid or long-finned fish and eat very small ones. Feed a varied diet of flake or pellet, frozen bloodworm, daphnia and brine shrimp. It does not need a heater in a temperate room and suits a tank of around 95 liters or more.

In the wild

Macropodus opercularis ranges across southern China, Taiwan, Vietnam and Laos, in rice paddies, ditches, ponds and slow streams. It comes from a subtropical climate and is notably cool-tolerant, thriving between about 10 and 22 degrees Celsius, so it is one of the few labyrinth fish suited to an unheated room. Keep the pH from 6.5 to 7.5. A planted tank with floating cover, gentle flow and a dark substrate suits it well, and a warm, humid gap under the lid protects the labyrinth organ.

Good to know

A member of the gourami family Osphronemidae, the paradise fish reaches about 8 centimeters and is known for its bold blue and red barring and flowing fins. Males build a floating bubble nest and guard the eggs and fry, driving the female away once spawning is done; breeding is rated hard mainly because of the male's aggression and the care the tiny fry need. It was one of the first ornamental fishes brought to Europe from Asia.

Did you know

The paradise fish was one of the earliest tropical fish kept in Europe, imported in the 1800s not long after the goldfish. Hardy and cool-tolerant, it can live in an unheated tank where most tropical fish would fail.