Smaragdina Betta

Looks how to spot one

Scales with iridescent cells

The body is covered in tiny hexagonal crystals that refract and interfere with light, producing a brilliant green and blue sheen. Males have longer ventral fins and more intense colouration; females are browner with less iridescence. The gill plates are green or blue, and the tail rays show wild spots.15

Personality what they are like

Betta smaragdina is generally peaceful and less aggressive than the common Betta splendens. Males can be kept together in a spacious tank without fighting, though individual jarring may increase aggression. In the wild it is used as a fighting fish in parts of Laos, but in captivity it is known as the 'peaceful betta'.64

Daily activity how busy a day looks

Moderate activity; enjoys exploring planted tanks with hiding places. Not a strong swimmer, so avoid strong currents.5

Grooming and care the hands-on bits

Low maintenance. Keep water clean and well filtered. Water chemistry is not critical; they thrive in a wide range of conditions. Temperature should be in the mid 70s to low 80s °F (about 24-28 °C). Provide caves and plants for cover.54

Home where they are happiest

In the wild, lives in still or sluggish waters such as rice paddies, swamps, roadside ditches, streams and ponds, usually shaded by vegetation with a substrate of leaf litter, mud or sand. In captivity, a pair can be kept in a 10-gallon tank; groups need 30 gallons or larger. Provide caves, plants and floating cover. They are bubble-nest builders and need calm water surface for nest construction.15

Food basics what goes in the bowl

In the wild feeds on terrestrial and aquatic invertebrates. In captivity, accept live or frozen foods such as Daphnia, Artemia (brine shrimp), bloodworms, white worms and black worms. A high-protein diet should be used sparingly to avoid liver issues.13

Company who they like around

Can be kept in pairs, species tanks or community tanks. Best to keep equal numbers of males and females, or more females than males, to reduce aggression. Males are not very combative and can coexist in a large aquarium. Not known to be venomous or illegal to keep, but check local regulations as with any wild species.54

The story where it all began

Betta smaragdina was first described by Ladiges in 1972. Its scientific name comes from the Latin word for emerald colour, referring to the male's brilliant green breeding dress. It has long been popular among wild betta enthusiasts but is rarely available in the general aquarium trade. The species is also known as the 'peaceful betta' because it is less aggressive than Betta splendens. In the Isan region of Thailand and in Laos, it is sometimes used as a fighting fish. The 'alien' hybrid betta is a cross of wild bettas including B. smaragdina.16

Recognised by the official bits

FishBase

Listed as a valid species with fisheries and aquarium interest.2