Emerald Betta

Geographical Origin & Biotope:

Native to the Khorat Plateau (in northeastern Thailand / Isan region) and parts of Laos, in the Mekong and Mun river basins. They inhabit classic tropical lentic ponds: warm, still swamps steeped in muddy clay, agricultural drainage canals, flooded rice fields, and stream margins that dry up into isolated muddy pools during the dry season.

Taxonomy & Morphology:

Belongs to the Osphronemidae family and is a prominent member of the *Betta splendens complex* (which includes *Betta mahachaiensis*, *imbellis*, and *splendens*). Compared to commercial variants, the *smaragdina* boasts slender and tapered proportions, a stocky jaw, and short ventral, anal, and dorsal fins (Plakat form) designed for rapid, darting swimming in waters cluttered with branches or roots, rather than for ornamental floating.

Social Behavior:

They have fascinating visual interactions. A healthy male is recognized when, in front of a mirror or a rival, he extends the branchial membrane (which forms an impressive black "beard" under the chin) and raises all his fins in a display of maximum static tension (flaring), whose colors shine madly in the dark amber water.

Coloration & Sexual Dimorphism:

The scientific name *smaragdina* (which derives from Latin for emerald) explains everything. The body color in adult males (particularly in the variant commonly known as "Guitar") is entirely covered by iridophore scales that refract a blinding emerald green or bluish-green light, similar to the metallic carapace of a shiny beetle, over a blackish background. The red fins are heavily striated and covered by the same emerald or pale blue scaling, creating a luminous turquoise "cobweb" effect. Females are noticeably more faded, brownish, crossed by classic horizontal stress lines or vertical lines during readiness for mating, and have much more transparent and shorter fins.

Tank Setup:

Do not house wild Bettas in bowls or bare 10-liter (2.5-gallon) mini-cubes; it would be a sacrilege. They have short fins (Plakat) and are powerful, active swimmers: an aquarium of at least 50-60 liters (15 gallons, minimum 60 cm / 2 feet in length) is the requirement to house a stable pair. The perfect scenario is a dark, gloomy *Blackwater* setup: fine amber sand on the bottom, numerous tangled branches or mangrove roots, and a thick blanket of real dry leaves (Indian Almond, Oak, Alder) laid on the substrate. These leaves will not only release tannins that acidify the water imitating their habitat, but will also host useful micro-colonies of infusoria. Dim lighting filtered by *Salvinia* or *Frogbit*. A sponge filter is ideal to avoid creating any water movement.

Diet & Feeding:

Wild Bettas will rarely accept dried commercial pellets or low-quality flakes right after being introduced to the tank. They are voracious insectivores and ruthless micro-predators. To keep morale high and stimulate the immune system, their diet must be meat-based: small mosquitoes fallen into the water, *Drosophila* (fruit flies) on the surface, as well as live/frozen food such as red bloodworms, daphnia, brine shrimp nauplii, and tubifex. Overfeeding them is dangerous, as they eagerly gulp the food before it sinks.

Water Quality:

Originating from temporary marginal pools and swamps in northeastern Thailand, they tolerate temperatures that vary greatly in nature, but in the aquarium they do excellently at 24-28°C (75-82°F). They thrive in soft (GH 2-10) and acidic to neutral waters (pH 6.0 - 7.5). They must have free and vital access to the water surface to breathe air via the labyrinth organ, which is why the aquarium must be sealed with a glass lid that retains moisture and heat.

Compatibility & Tankmates:

Despite the aggressive nature of the genus, the *Smaragdina* is considered much more "peaceful" than its *splendens* cousin. Males will open their gill covers (flaring) and extend their fins to frighten each other in magnificent ritual displays, but in well-sized tanks they will rarely kill each other, limiting themselves to lightning-fast skirmishes or chases that end with the loser hiding among the dry leaves. Keeping a solitary pair in a dedicated tank produces the most interesting reproductive and bonding behaviors. You can add mid/bottom-dwelling micro-cyprinids (e.g., *Boraras* or small Corydoras), but be aware they will eat the offspring of Neocaridina shrimp.

Aquarium Breeding:

During the mating season, the male will turn an almost toxic emerald green, with the black operculum contrasting fiercely. He will create a bubble nest, usually under broad floating leaves (or a half plastic cup inverted at the water surface inserted by the breeder). The reproductive embrace is identical to that of classic Bettas. Wild females are better tolerated by the male after spawning if there are enough hiding places.

Risks & Diseases:

The greatest risk is not disease (they are genetically very robust), but ballistic escape. Wild Emerald Bettas are exceptional jumpers and can find microscopic gaps between the filter pipe and the glass. Obsessively check that the aquarium is watertight at the top.