Vietnam Betta (Betta smaragdina)

Betta smaragdina, commonly called the Emerald Betta or Vietnam Betta, is a wild betta species from the Mekong drainage in Thailand, Laos, and Vietnam. Distinguished from the common Siamese Fighting Fish (B. splendens) by its less exaggerated fins and more robust body, it displays stunning emerald-green iridescent scaling across the flanks and operculum with vivid red-blue fin coloration — a color pattern that earns it the 'smaragdina' (emerald) name.

Unlike the highly domesticated B. splendens, the Vietnam Betta retains stronger wild instincts and is typically more active and less prone to fin damage in appropriate setups. Males are still aggressive toward each other and cannot be housed together, but they are somewhat more tolerant of active, non-threatening tankmates compared to fancy bettas.

Betta smaragdina is a labyrinth fish that breathes atmospheric air. It prefers well-planted, calm water with floating plants for cover and bubblenest building. Soft, slightly acidic water that mimics its natural lowland floodplain and rice paddy habitat is ideal.

This species is a bubblenest builder that spawns readily in appropriate conditions. It is a fascinating and rewarding alternative to domesticated bettas for aquarists interested in wild-type fish.

Water Parameters: Soft, slightly acidic water: pH 6.0–7.5, temperature 24–28°C, GH 2–12. Tannin-stained water from Indian almond leaves and driftwood is beneficial and replicates its natural environment. Gentle filtration with minimal flow.

Tank Setup: Minimum 60 liters for a single male. Provide floating plants (frogbit, water lettuce) for bubblenest building and cover. Dense fine-leafed plants, driftwood, and Indian almond leaves. Gentle sponge filtration. A secure, tight-fitting lid is mandatory — they jump.

Feeding: Carnivore that accepts live and frozen foods primarily: bloodworm, daphnia, brine shrimp, and small insects. Will accept quality betta pellets but live/frozen foods are preferred and important for health. Feed once to twice daily in moderate amounts.

Tankmates: Keep one male per tank — extreme aggression toward conspecific males. Can be kept with small, peaceful, non-flashy fish that won't provoke aggression: small cories, small tetras, and similar. Avoid any fish that resembles another betta (bright fins, similar body shape). A species tank is often safest.

Breeding: Bubblenest builder. Male builds nest under floating plants. After spawning embrace, male collects and places eggs in nest. Remove female after spawning. Male guards nest and fry. Fry require infusoria and micro-brine shrimp.