Roundtail paradise fish

Macropodus ocellatus

A rounded tail separates it from fork-tailed paradise fishes; populations vary in colour.

A rounded tail distinguishes it from fork-tailed paradise fishes; the postorbital stripe does not join the opercular spot, and populations vary in colour.

Adult length: Up to 8 cm (standard length, without the tail fin)
Water temperature: 10–22 °C
pH: 6–7.5
Hardness: 5–20 dGH

Natural habitat: Occupies irrigation ditches, rice fields, pools, marshes, streams and river backwaters; water surfaces may freeze in parts of its range in winter.

Keep at 10–22°C, pH 6.0–7.5 and 5–20 dGH. Allow a cool winter period depending on the stock's origin; it is not a fixed year-round temperature.

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Appearance and identification

Adult males develop extended fin rays; assess sex with age, shape and reproductive condition together.

Social behaviour and territory

A spacious, well-covered aquarium can allow group interactions, but breeding males still defend nests and chase other fish.

Compatibility limits

Groups require more covered space; nesting males remain territorial.

Space requirements

Allow an 80 × 30 cm aquarium base for a single pair. Additional fish need more room and cover.

Aquarium environment

Its labyrinth organ supports air breathing. Leave access to the surface when arranging floating plants.

Diet and feeding

Offer appropriately sized frozen or live foods such as daphnia and brine shrimp. Some fish accept dry foods; check intake and condition.

Sources