A beautiful wild-type Betta species native to the Khorat Plateau of Thailand, known for its striking iridescent emerald-green scales. Unlike the domestic Betta splendens, they are slightly more peaceful and closely resemble their natural wild form. They are excellent jumpers and require tight-fitting lids.
Betta Smaragdina At a Glance
Betta Smaragdina Tank Requirements
Will Betta Smaragdina fit in your tank?
Care guides tell you what Betta Smaragdina needs, the next question is whether your tank can safely provide it. Test Betta Smaragdina against your tank size, maintenance needs, and the fish you already keep before you buy.
Useful setup supplies
We may earn from qualifying purchases
Betta Smaragdina Water Parameters
Water care products
We may earn from qualifying purchases
Betta Smaragdina Temperament & Compatibility
Betta Smaragdina Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Male
The male features brilliant iridescent green or blue scaling and extended fins. Highly territorial towards other males; strictly one male per tank. Can sometimes be kept with females in large, densely planted tanks, but caution is advised.
Differs in 2 traits from base species
Also known as: Male Emerald Betta, Standard Male
Male (Guitar Morph)
A highly sought-after locale variant known for specific tail webbing that resembles guitar strings, and typically a slightly larger build. Care and temperament are identical to the standard male.
Differs in 3 traits from base species
Also known as: Guitar, Betta smaragdina sp. Guitar, Guitarra
Female
Females are duller in coloration (mostly brownish with faint green iridescence) and have shorter fins. They are generally peaceful but will establish a pecking order. Multiple females can be kept in a group if the tank is heavily planted and spacious enough (40L+ recommended for groups).
Differs in 2 traits from base species
Also known as: Female Emerald Betta
Betta Smaragdina Care Guide Summary
The Betta Smaragdina, scientifically known as Betta smaragdina, belongs to the Anabantoids family group. Adults reach a maximum size of approximately 6 cm and have a compressed body shape with a moderate growth rate. Classified as semi-aggressive, this species primarily occupies the surface and mid-level zones of the aquarium and produces a low level of biological waste.
To thrive, the Betta Smaragdina requires a freshwater only aquarium with a minimum volume of 20 litres and a tank length of at least 30 cm. Water temperature should be maintained between 22°C and 28°C, with a pH range of 5.5–7.5 and a general hardness of 2–12 dGH. A low water flow is preferred.
Due to its specialist needs, the Betta Smaragdina is best suited for fishkeepers who can provide a carefully planned setup. This species is available in 3 varieties: Male, Male (Guitar Morph), and Female. Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.
Betta Smaragdina Habitat Setup
When setting up an aquarium for the Betta Smaragdina, a low water flow best suits their natural preferences. Because this species occupies the surface and mid-level zones, the aquarium layout should prioritise adequate surface area with floating cover to make them feel secure near the waterline and open swimming space in the centre of the tank for free movement. Useful additions include leaf litter or blackwater tannins to replicate their natural soft-water habitat, dense planting to provide cover, break sightlines, and reduce stress, and floating plants to diffuse overhead light and create shaded areas. Keepers should note that a tight-fitting lid is essential, as this species is a known jumper.
Betta Smaragdina Compatibility Notes
Classified as semi-aggressive, the Betta Smaragdina is adaptable and can be kept singly or in a small group, offering flexibility when planning a community tank. When choosing tankmates, ornamental shrimp are not safe companions, conspecific aggression can be intense, especially in smaller tanks, and territorial behaviour may cause issues if hiding spots or floor space are limited. Selecting tankmates that favour different water layers from the surface and mid-level zones can help reduce competition and territorial overlap.
Betta Smaragdina Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Betta Smaragdina.
10 Gallon Standard
15 Gallon Standard
20 Gallon High
20 Gallon Long
29 Gallon Standard
30 Gallon Breeder
Show 26 more tank sizes
Betta Smaragdina Feeding & Diet Considerations
The Betta Smaragdina will hunt and eat ornamental shrimp, making it unsuitable for shrimp-focused setups and will eat fry, so breeding efforts in the same tank are unlikely to succeed.
Feeding products
We may earn from qualifying purchases
.webp?2026-04-25T14%3A35%3A38.022Z)
Frequently Asked Questions About Betta Smaragdina
How big does Betta Smaragdina get?
Betta Smaragdina (Betta smaragdina) typically reaches a maximum adult size of approximately 6 cm. They have a compressed body shape and a moderate growth rate.
What tank size does Betta Smaragdina need?
A minimum aquarium volume of 20 litres and a tank length of at least 30 cm are recommended for Betta Smaragdina. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Betta Smaragdina need?
Betta Smaragdina thrives in freshwater only conditions with a temperature range of 22–28°C, a pH between 5.5 and 7.5, and a general hardness of 2–12 dGH. A low water flow is preferred.
Is Betta Smaragdina peaceful or aggressive?
Betta Smaragdina is classified as semi-aggressive with an aggression score of 5 out of 10. They can work in community setups but may clash with certain tankmates.
Can Betta Smaragdina live alone?
Yes, Betta Smaragdina can be kept singly or in a group. They are flexible and adapt well to both setups.
Is Betta Smaragdina safe with shrimp?
No. Betta Smaragdina is known to eat ornamental shrimp and is not recommended for shrimp tanks. Even larger shrimp species like Amano Shrimp may be at risk.
Does Betta Smaragdina have any special tank requirements?
Yes. Betta Smaragdina benefits from plants - densely covered, plants - floating, and leaf litter/blackwater in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Does Betta Smaragdina need a lid on the tank?
Yes. Betta Smaragdina is a known jumper, and a tight-fitting lid or cover is essential to prevent escape. Even a small gap can be enough for a determined fish to leap out.
Plants That Suit Betta Smaragdina
These plants pair well with Betta Smaragdina based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
Amazon Frogbit
Limnobium laevigatum
Asian Watergrass
Hygroryza aristata
Asian Watermoss
Salvinia cucullata
Carolina Mosquito Fern
Azolla caroliniana
Common Duckweed
Lemna minor
Crystalwort
Riccia fluitans
Fish Similar to Betta Smaragdina
Betta Imbellis
Betta imbellis
Known as the 'Peaceful Betta', Betta imbellis is a wild species closely related to Betta splendens. Unlike their highly aggressive domestic cousins, they can often be kept in pairs or carefully managed groups. They are native to blackwater swamps and require calm, tannin-stained water with plenty of cover. They are exceptionally prone to jumping.
Emerald Green Cory
Corydoras splendens
Formerly classified as Brochis splendens, the Emerald Green Cory is significantly larger, taller, and chunkier than typical Corydoras. Known for their striking metallic emerald green and blue sheen, they are highly social, peaceful bottom-dwellers. They must be kept in groups and require a soft sand substrate to protect their delicate sensory barbels from erosion.
Betta Macrostoma
Betta macrostoma
Known as the 'Brunei Beauty', Betta macrostoma is a large, highly sought-after wild mouthbrooding Betta. They possess a massive mouth and are voracious predators. Native to highly acidic, soft blackwater streams in Borneo, they require cool, pristine water to thrive. They are extremely prone to jumping and require a tight-fitting lid.
Sparkling Gourami
Trichopsis pumila
A stunning nano species known for its iridescent blue/green eyes, body spots, and ability to make audible 'croaking' sounds. Unlike many anabantoids, they are social and best kept in groups. However, they are efficient micropredators that will hunt shrimp fry and pests like hydra. Requires stable water parameters and dense planting.
Emerald Eye Rasbora
Brevibora dorsiocellata
A small, active schooling fish native to Southeast Asia, famous for the striking black-and-white spot on its dorsal fin and its reflective 'emerald' eyes. They are highly peaceful and thrive in heavily planted or blackwater aquariums. As a strict schooling species, they must be kept in groups to feel secure, establish a natural hierarchy, and display their best colors.
Emerald Dwarf Danio
Danio erythromicron
An exquisite, tiny cyprinid endemic to Lake Inle in Myanmar. Known for their striking emerald vertical bands and reddish-orange fins. Because they originate from a slightly alkaline mountain lake, they prefer cooler, harder water than many tropical fish. They are notoriously shy and must be kept in schools in heavily planted tanks with broken sightlines to feel secure.