Macropodus ocellatus – Roundtail Paradise Fish
Macropodus ocellatus was first described by Theodore Edward Cantor in 1842. This fish belongs to the family Osphronemidae, which are known as the gouramies. The genus name Macropodus comes from the Greek “makros” (large) and “pous” (foot), referring to the long fins of the fish in this genus. The species name “ocellatus” means “with small eyes” referring to the black spot on the gill cover. Their common name is Roundtail Paradise Fish.
Synonym: Polyacanthus paludosus.
Description
Macropodus ocellatus has a rounded caudal fin, which gives the species its name. The body is grey-yellow with white stripes on the head and a characteristic eyespot on the gill cover. The fins are red and yellow, with the tips extending beyond the caudal fin. The maximum length is about 8 centimeters.
Differences between males and females: Males are larger, more colorful, and have elongated fin rays, while females are smaller and less brightly colored.
Behavior and Temperament: These fish are generally peaceful, but males can be territorial during breeding. They can be kept in groups but are less suitable for a community tank.
Life expectancy: In an aquarium, they can live for 3-5 years.
Biotope
Macropodus ocellatus is native to China, Korea, Japan, and possibly northeastern Vietnam. It lives in slow-moving or stagnant waters such as rice paddies, ponds, and swamps.
Their natural habitat often has dense vegetation and may be covered with ice in winter. The bottom is usually mud or fine sediment.
They live in a temperate climate with cold winters.
Diet
In the wild, they feed on insect larvae and small invertebrates. In the aquarium, they can be fed live or frozen food such as Daphnia and Artemia. It is advisable not to give dry food as a staple food.
The Aquarium
Macropodus ocellatus is challenging to keep in an aquarium due to its specific temperature requirements. This fish must hibernate below 10 degrees Celsius, meaning it is better suited to a pond than a standard aquarium. However, it is not completely winter-hardy, requiring extra care in colder climates.
For an aquarium, a minimum size of 80 centimeters and 80 liters is recommended for a pair. If you want to keep multiple pairs, a larger aquarium is necessary. The aquarium should be densely planted with floating plants and hiding places of wood or stones. A sand or fine gravel substrate is ideal.
The best water conditions for this species are a temperature of 10-22°C, a pH of 6.0-7.5, and a hardness of 5-25 dH. Providing an environment that mimics the fish’s natural habitat is important, with plenty of hiding places and a quiet environment.
The young Macropodus ocellatus cannot overwinter outside and must be brought inside quite early in the season, around the end of August. This means that you must pay extra attention to the temperature and conditions in the aquarium during the summer months.
As for tankmates, Macropodus ocellatus can live well with other peaceful fish that require the same temperature. However, it is important to avoid aggressive or much larger species because Macropodus ocellatus is a relatively peaceful fish.
Breeding aquarium and conditioning
A special aquarium with soft water and a slightly elevated temperature is recommended for breeding. The temperature should be at least slightly above 20 ° Celsius. The fish can be conditioned with live food. It is not necessary to separate the male and female beforehand.
The spawn
During spawning, the Macropodus ocellatus’s colors become more intense. The male builds a bubble nest at the water’s surface, often between floating plants. Courtship begins when the male shows his elongated fins and tries to attract the females to the nest.
Courtship and Mating Posture: The male circles the female, displaying his colors and fins to attract her attention. When the female is ready to mate, her color changes to a paler shade. Mating occurs under the bubble nest, with the male embracing the female in a typical “embrace” characteristic of osphronemids.
Egg Deposition: During the embrace, the eggs and sperm are released. The eggs contain a drop of oil that makes them float to the bubble nest. The male often helps by carrying the eggs to the nest with his mouth. This process is repeated until the female has deposited all her eggs, amounting to several hundred eggs.
After Spawning: After spawning, the male guards the eggs and nest, while the female is usually kept away to avoid disturbance.
During spawning, the colors of the fish become more intense. The male builds a bubble nest, and mating usually occurs under the nest. Several hundred eggs are laid, which float to the nest.
Raising the fry
The eggs hatch after 3-4 days. The young remain in the nest until their yolk sac is absorbed, and after a few days, they begin to swim freely.
There is no parental care after hatching. The young are fed infusoria and later microworms.
Particularities
Macropodus ocellatus is well adapted to cold temperatures and can be kept (with some care) in ponds. They are less aggressive than other paradise fish.
Conclusion
Macropodus ocellatus is an interesting fish for advanced aquarists because of its cold-temperature adaptability and unique breeding behavior. They are not difficult to keep but require specific conditions for breeding. Their peaceful nature makes them suitable for a special aquarium but less so for a community tank.
Video
Author
John de Lange
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