绿宝抟鱼 · Emerald Betta

Overview

Green gill-cover iridescence is characteristic of Betta smaragdina, a bubble-nesting betta with locality-dependent red and green patterning. Selective breeding and hybridization have produced ornamental forms absent from nature, making population and lineage information valuable.

Distribution & habitat

The species is native to the Khorat Plateau in eastern Thailand and Mekong tributaries in central Laos. It occupies rice fields, swamps, ditches, streams, and ponds with still or slow water, often under aquatic or marginal vegetation. Some sites have little dissolved oxygen.

Monsoon conditions can change rapidly, over bottoms ranging from leaves to mud, sand, or deep sediment. Releases of ornamental and other bettas have affected the genetic integrity of some wild populations.

Aquarium setup

Allow at least approximately 45 × 30 cm of floor space for a pair. Dense plants, shade, and surface cover suit it. Wood, pots, and pipes add retreats, while leaves encourage microorganisms useful for fry.

Avoid strong currents; gentle sponge filtration is sufficient. A secure lid prevents jumping, with warm, humid air left above the water for breathing.

Diet & feeding

Aquatic and terrestrial invertebrates are likely wild prey. Captive fish generally recognize dry foods after acclimation, alongside regular live or frozen Daphnia, Artemia, and bloodworms. Limit portions to avoid obesity.

Behaviour & compatibility

Dedicated keeping is usually preferable to an ordinary community. Other species must be exceptionally peaceful and environmentally compatible. Several males may coexist with sufficient cover, although a separate pair is preferable for reproduction.

Sexual dimorphism

Males show stronger color and increasingly extended fins at maturity.

Breeding

Female refuges are essential. The male builds in a container or tube, under a broad leaf, or among floating plants, generally excluding her until completion. A receptive female pales and develops dark flank bars. Repeated embraces beneath the nest release eggs, caught by her pelvic fins and transferred upward by the male; she also retrieves stray eggs.

Adults can usually remain after spawning, but the male takes sole responsibility. Hatching occurs in roughly 24–48 hours, with larvae staying in the nest another 3–4 days while absorbing yolk. He retrieves fallen young and may relocate the entire nest if threatened. Interest fades after free swimming, and adults generally spare the offspring.

Initially the fry need infusoria-sized foods for several days, followed by microworms and Artemia nauplii. Avoid excessive reliance on Artemia. Regular small water changes and warm, moist air beneath a close-fitting cover support development.

Notes

Some lines have been selected for aggression, while ornamental breeding has included crosses with other bettas. Keep locality information for wild populations and preserve separate lines. Natural identification features include green gill-cover scales, tail crossbars, and absence of a red crescent-shaped band at the tail margin.