叉尾斗鱼 · Paradise Fish

Overview

The fork-tailed Macropodus opercularis is a long-established ornamental labyrinth fish. Typical fish show blue bars against a reddish background, while commercial breeding has produced albino, red, blue, and stripeless forms. Male territorial behavior remains a major stocking consideration.

Distribution & habitat

Its native range includes China south of the Yangtze, Taiwan and Hainan, northern and central Vietnam, and northeastern Laos. Introduced populations occur in countries including Korea, Japan, Malaysia, Singapore, India, and the United States, largely associated with the aquarium trade.

It uses varied habitats, from lowland streams, backwaters, and natural pools to canals, rice fields, and reservoirs. Some populations also occupy upland streams.

Aquarium setup

A pair needs at least approximately 80 × 30 cm of floor space. Roots and branches create shade. Include floating or surface plants if breeding is intended, and leaves can add cover and microorganisms for fry. Furnished or bare-bottom arrangements are both usable according to maintenance needs.

Heating is often unnecessary under suitable conditions. A cooler winter interval may be beneficial rather than maintaining high tropical temperatures throughout the year.

Diet & feeding

Insect larvae and similar prey are likely natural foods. Offer small live or frozen Daphnia, Artemia, and worms. Some quality dry foods are accepted, particularly by commercially bred strains.

Behaviour & compatibility

Avoid similarly shaped fishes likely to prompt conflict. Peaceful schooling companions with matching environmental needs are better candidates. Male territorial aggression increases during reproduction; several males require a very large tank. Two or more females per male can distribute attention, provided space and retreats are sufficient.

Sexual dimorphism

Males attain greater size and show longer soft-ray extensions in the dorsal, anal, and caudal fins.

Breeding

The male builds a bubble nest among surface vegetation and normally tolerates females nearby during construction. Prior separation is unnecessary. Soft water with a slight temperature increase is reported to encourage breeding. A close-fitting cover preserves warm, moist air for labyrinth development.

Fin displays precede repeated embraces under the nest. Eggs contain oil droplets and float upward, often guided by the male. Several hundred eggs are typically produced over successive batches.

Adults may initially remain if the female has shelter. Sometimes the nest fragments and eggs are collected into a clump. Hatching occurs in roughly 3–4 days, with larvae remaining until yolk absorption. Once free swimming begins and paternal interest fades, remove the adults.

Infusoria-sized foods are needed for the first few days, followed by microworms and Artemia nauplii. Make frequent small water changes.

Notes

Imported to France in 1869 and bred there that year, it was among the earliest ornamental fish brought to Europe. Typical wild characters include the forked tail, a dark gill-cover spot edged reddish behind, and an eye stripe joining that spot. Ornamental color changes make shape and lineage useful alongside pattern.