All fish / Osphronemidae

Emerald Betta

Betta smaragdina

Also known as emerald betta, blue betta, smaragdina, smaragdina betta, wild betta, green betta, betta smaragdina guitar, emerald fighting fish, ปลากัดอีสาน, ปลากัดเขียว, ikan laga zamrud, ベタ・スマラグディナ

A wild bubble-nesting fighting fish from the rice paddies and swamps of northeast Thailand and nearby areas. Males have rows of shiny emerald to blue-green scales over a brown body, with green-edged fins that light up when they display. Keepers like it as a hardy, natural-looking relative of the domestic betta.

Care at a glance

Care level

Easy

Temperament

Semi

Adult size

6 cm

Temperature

22 to 28 °C

pH

6 to 7.5

Smallest tank

40 litres

Keep as

One male with one or two females, or a single fish

Diet

Carnivore: live and frozen bloodworm, daphnia, brine shrimp, mosquito larvae and quality small pellets

Swims

Top of the tank

Lifespan

3 to 5 years

Water

Freshwater

Wild range

Northeastern Thailand, Laos and Cambodia (Mekong basin, Khorat Plateau)

Breeding

Males build a bubble nest at the surface, usually among floating plants, and embrace the female beneath it. The male then guards the eggs and fry. Breeding is fairly easy in a quiet, warm tank with low flow and floating cover, but take the female out once spawning is over.

Good to know

Males fight each other hard, so keep only one male per tank unless it is very large and well planted, and cover the tank because they jump. Wild-type fish are often crossed with Betta splendens, so pure stock may be labelled loosely.