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Betta hendra Care Guide – Tank Setup, Feeding and Breeding

ByTankora

Quick summary

Betta hendra is a striking but demanding, Critically Endangered wild betta that needs extremely soft, acidic blackwater and is not suitable for beginners. It’s best attempted by experienced aquarists comfortable using RO water, monitoring low pH, and feeding live foods, in a species-only or very carefully chosen blackwater tank.

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In this guide:

Introduction

Betta hendra is a small, strikingly beautiful wild betta from the peat swamp forests of Central Kalimantan, Borneo. Described relatively recently by Schindler and Linke in 2013, this species belongs to the coccina group – a complex of diminutive, jewel-like bettas that inhabit some of Southeast Asia’s most threatened blackwater habitats. The species was named in honour of Hendra Tommy, an Indonesian aquarium shop owner who first discovered and exported the fish, bringing it to the attention of the wider ichthyological and aquarist community.

What sets Betta hendra apart from the majority of its coccina-group relatives is its extraordinary iridescent green colouration, a trait shared by only two other members of the group: Betta persephone and Betta miniopinna. Where most coccina-complex species display the familiar deep reds and blacks, Betta hendra males in full breeding colour shimmer with vivid green-blue iridescence across their bodies and fins – a genuinely arresting sight in a properly set up blackwater aquarium.

Betta hendra is listed as Critically Endangered by the IUCN, with its entire known range restricted to the Sabangau River basin in Central Kalimantan. Habitat destruction through logging, drainage of peat swamp forests, and agricultural conversion threaten the species’ survival in the wild. Responsible captive breeding by dedicated hobbyists therefore plays a meaningful role in maintaining viable populations of this rare fish outside its native range. Keeping Betta hendra is a rewarding but specialised endeavour, demanding soft, acidic blackwater conditions and a thoughtful approach to tank setup and husbandry.

Quick Stats

Scientific name Betta hendra
Common names Betta hendra, Hendra’s Betta
Family Osphronemidae
Origin Sabangau River basin, Central Kalimantan, Borneo, Indonesia
Adult size 3.5 – 4 cm
Lifespan 3 – 5 years
Difficulty Difficult
Breeding difficulty Moderate
Temperature 22 – 27 °C
pH range 3.5 – 6.0
General hardness (GH) 0 – 4 dGH
Carbonate hardness (KH) 0 – 2 dKH
Minimum tank size 30 litres
Conservation status Critically Endangered (IUCN)

Appearance

Betta hendra is a small, slender fish with an elongated body shape typical of the coccina group. Adults reach a maximum total length of around 3.5 to 4 centimetres, making them one of the more petite bettas available to hobbyists. The body is laterally compressed, and the overall profile is elegant and streamlined, well suited to navigating the dense tangles of submerged roots and leaf litter in its native habitat.

The base body colour is a rich, dark brownish-red to wine-red, which can appear almost black under subdued lighting. A prominent dark lateral stripe runs from the snout through the eye to the caudal peduncle, and in some individuals, additional faint vertical barring may appear on the flanks, particularly in females or subdominant males. The opercular (gill cover) region often shows a subtle dark blotch.

The most remarkable feature of Betta hendra is the vivid iridescent green colouration displayed by males in breeding condition. This is genuinely exceptional within the coccina group. While the majority of coccina-complex species – Betta coccina, Betta livida, Betta brownorum, Betta tussyae, and others – display red and black patterning with at most a blue-green spot on the flanks, Betta hendra males develop extensive, brilliant green to blue-green iridescence across the body, dorsal fin, anal fin, and caudal fin. Under the tannin-stained, dimly lit conditions of a well-maintained blackwater aquarium, this iridescence catches and scatters light in a way that is simply breathtaking. The green sheen extends across the unpaired fins, contrasting beautifully with the dark base colouration and often bordered by narrow dark or reddish margins.

This green iridescence places Betta hendra in an exclusive trio within the coccina group, alongside Betta persephone and Betta miniopinna – the only three members to exhibit this colour rather than the group’s characteristic reds. For hobbyists accustomed to the warm tones of other coccina-complex species, encountering Betta hendra for the first time can be a revelation. The green is not a constant feature; it intensifies dramatically when the male is displaying to a female, defending territory, or otherwise in a heightened state of arousal. At rest, the fish can appear relatively plain, but the transformation during display is one of the great pleasures of keeping this species.

The pelvic fins are elongated and narrow, often tipped with white or light blue, which adds a further point of visual interest during courtship displays when the male extends and fans them. Females are considerably less colourful, typically displaying a uniform brownish body with faint barring and little or no iridescence. They are also slightly smaller and less heavy-bodied than males.

Betta hendra is most easily confused with its closest geographic relative, Betta uberis, which also occurs in Kalimantan. The most reliable distinguishing feature is the dorsal-fin ray count: Betta hendra possesses 10 to 12 dorsal-fin rays, while Betta uberis has 14 to 17. However, it must be noted that this is a diagnostic character requiring close examination or a good photograph – it is not something most hobbyists can readily verify at a glance in a living, moving fish. In practice, provenance and reliable sourcing from reputable breeders remain the most practical means of confirming species identity.

Natural Habitat

Betta hendra is endemic to the Sabangau River basin in Central Kalimantan, on the island of Borneo, Indonesia. Its habitat consists of peat swamp forest waterways – shallow, slow-moving or virtually still channels, pools, and flooded forest floor areas within dense tropical peat swamp. These environments are characterised by extremely soft, highly acidic water stained dark brown to almost black by the leaching of humic acids and tannins from decomposing plant material, primarily fallen leaves, branches, and peat substrates.

The water in these habitats is typically tea-coloured to the point of near-opacity, with pH values often falling between 3.5 and 5.0 – extraordinarily acidic by most freshwater standards. General hardness is essentially zero, and mineral content is negligible. The substrate is composed of deep layers of waterlogged leaf litter, peat, and decaying wood. Submerged roots, fallen branches, and dense tangles of aquatic and semi-aquatic vegetation provide abundant cover and structure.

Light penetration in these habitats is minimal, filtered first through the dense canopy of the peat swamp forest and then through the deeply stained water column. Temperatures tend to be warm and relatively stable, typically ranging from 22 to 27 degrees Celsius, though microhabitat variation exists. Dissolved oxygen levels are generally low, which has driven the evolution of the labyrinth organ – the specialised accessory breathing apparatus shared by all anabantoid fishes, including bettas – allowing Betta hendra to gulp atmospheric air at the surface.

The peat swamp forests of Central Kalimantan are among the most threatened ecosystems on Earth. Extensive logging, drainage for palm oil plantations, and deliberate burning have destroyed vast areas of this habitat. The Sabangau peat swamp forest, while partially protected, remains under ongoing pressure. The extremely restricted range of Betta hendra – known only from this single river basin – makes it acutely vulnerable to habitat loss, which is reflected in its Critically Endangered IUCN status.

Tank Size and Setup

A single pair or a small group of Betta hendra can be housed in an aquarium of 30 litres or more. For a pair, 30 litres is adequate, but a larger tank of 45 to 60 litres is preferable if keeping a trio (one male, two females) or a small group, and provides greater water volume stability – an important consideration given the extreme softness and acidity required. Betta hendra does not need a large swimming space; in the wild, it occupies very small, sheltered microhabitats within the peat swamp.

The tank should be set up to replicate the blackwater peat swamp as closely as possible. Begin with a thin layer of fine, inert sand or no substrate at all – bare-bottom tanks are practical and make maintenance easier. The key structural elements are leaf litter and driftwood. Add a generous layer of dried Indian almond leaves (Terminalia catappa), oak leaves, or other suitable botanical materials to the tank floor. These will slowly decompose, releasing tannins and humic acids that colour the water, lower pH, and provide beneficial surfaces for microbial biofilms – a supplementary food source for fry and even adults.

Driftwood pieces, particularly those with complex branching structures such as spider wood or Malaysian driftwood, should be arranged to create sheltered areas, overhangs, and visual barriers. These provide essential territory markers and hiding spots for subordinate fish and females. Small clay pots, coconut shells, or specially designed betta caves can serve as potential bubble nest sites, though males will often choose their own preferred location, frequently beneath a floating leaf or overhanging piece of wood.

Lighting should be kept subdued. Betta hendra originates from an environment where very little light reaches the water surface, and the deeply tannin-stained water further reduces light penetration. Bright lighting will cause the fish to appear washed out and stressed. Floating plants such as Salvinia, Riccia fluitans, or Amazon frogbit are highly recommended, as they dim the lighting naturally, provide cover at the surface, and can support bubble nests. Rooted plants are not essential but can be included if they tolerate very soft, acidic conditions – species such as Cryptocoryne and certain mosses (Java moss, for instance) can work well.

A tightly fitting lid is essential. Like all bettas, Betta hendra can and will jump, and the labyrinth organ requires access to warm, humid air above the water surface. A well-sealed lid maintains the warm air layer and prevents escapes.

Water Parameters

Temperature 22 – 27 °C
pH 3.5 – 6.0
General hardness (GH) 0 – 4 dGH
Carbonate hardness (KH) 0 – 2 dKH
Ammonia 0 ppm
Nitrite 0 ppm
Nitrate Below 10 ppm

Betta hendra is a genuine blackwater specialist, and its water chemistry requirements reflect this. The most critical parameter is pH, which should ideally be maintained between 4.0 and 5.5, though the species can tolerate a slightly broader range of 3.5 to 6.0. Keeping this fish in neutral or alkaline water is not recommended and is likely to result in stress, poor colouration, susceptibility to disease, and breeding failure.

To achieve and maintain these conditions, most keepers will need to use reverse osmosis (RO) water or very soft rainwater as their base, remineralised only minimally or not at all. Peat filtration, the addition of Indian almond leaves and other botanicals, and commercial blackwater extracts can all help to lower pH and introduce the tannins and humic substances that characterise the species’ native water. It is important to note that at very low KH values, pH can fluctuate rapidly, so changes should be made gradually and water chemistry should be monitored regularly, particularly during water changes.

Temperature should be maintained in the range of 22 to 27 degrees Celsius. The lower end of this range is often preferred, and many successful keepers maintain their Betta hendra tanks at around 23 to 25 degrees Celsius. Overheating should be avoided.

Ammonia and nitrite must be maintained at zero at all times, as with any aquarium fish. Nitrate should be kept below 10 ppm through regular partial water changes using appropriately conditioned, soft, acidic replacement water. It is essential that replacement water is matched as closely as possible to the tank water in terms of temperature, pH, and hardness to avoid shocking the fish.

Filtration and Equipment

Filtration for a Betta hendra tank should be gentle and effective. Air-driven sponge filters are the most widely recommended option, providing biological filtration with minimal water flow. Betta hendra, like other coccina-group species, inhabits virtually still water in the wild and does not appreciate strong currents. An oversized sponge filter rated for a larger tank than you are using can provide excellent biological filtration without generating excessive flow.

Small internal filters or hang-on-back filters can also be used, provided the flow rate is reduced to a gentle trickle. Baffling the outflow with a sponge or directing it against the glass can help to minimise current. Canister filters are generally unnecessary for the small tank volumes typically used for this species, though a small canister filled with peat or other acidifying media can serve a dual purpose of filtration and water chemistry management.

A heater may or may not be required depending on the ambient temperature of the room in which the tank is housed. If the room temperature consistently falls below 22 degrees Celsius, a small, reliable, adjustable heater is necessary. In warmer climates or heated fish rooms, a heater may be unnecessary. If used, a heater guard is advisable to prevent the fish from resting against the heating element and sustaining burns.

As noted above, a tightly fitting lid is essential. Lighting should be low-intensity. Standard LED aquarium lights can be used but should be dimmed or partially blocked by floating plants. A timer set for 8 to 10 hours of light per day is sufficient. Some keepers prefer to use no artificial lighting at all, relying on ambient room light, which can produce a very natural and attractive effect in a well-set-up blackwater tank.

An air pump (if using a sponge filter) should be set to produce a gentle stream of bubbles rather than vigorous agitation. The labyrinth organ means Betta hendra is not dependent on dissolved oxygen levels in the water, but some gentle surface movement helps to prevent the formation of bacterial films on the water surface.

Diet and Feeding

Betta hendra is a micro-predator that feeds primarily on small invertebrates, insect larvae, and zooplankton in the wild. In captivity, the species can be somewhat particular about food, and newly acquired or wild-caught specimens may initially refuse prepared foods entirely.

The staple diet should consist of small live or frozen foods. Daphnia, baby brine shrimp (Artemia nauplii), micro worms, grindal worms, Moina, and mosquito larvae are all excellent choices and are typically accepted with enthusiasm. Frozen foods of similar types are usually accepted once the fish have settled, though live food is strongly preferred and should be offered regularly to maintain optimal condition and encourage breeding behaviour.

High-quality micro pellets or crushed flake food may be accepted by some individuals, particularly those that have been captive-bred and raised on prepared foods. However, prepared foods should not form the sole diet. A varied diet rich in live and frozen invertebrates will produce the best colouration, health, and breeding condition.

Feed small amounts once or twice daily, offering only what the fish can consume within a few minutes. Overfeeding in the small, low-pH tanks typically used for this species can rapidly degrade water quality. Uneaten food should be removed promptly. A weekly fast day can be beneficial for adult fish.

Behaviour and Temperament

Betta hendra is a relatively peaceful species by betta standards, though males are territorial and will display to and occasionally spar with rival males. Aggression is generally ritualised rather than damaging, consisting of flaring, lateral displays, and fin spreading. Serious injuries are uncommon in appropriately sized, well-structured tanks with adequate visual barriers and hiding spots.

In a suitably furnished tank, a pair or a small group consisting of one male and two or three females can be maintained together without significant problems. Some experienced keepers successfully maintain pairs of males together in larger, heavily planted and decorated tanks, though this requires careful observation and a willingness to separate individuals if aggression escalates. In general, keeping a single male with one or more females is the safest approach.

Betta hendra is a shy, retiring species that spends much of its time hovering among leaf litter, beneath overhanging driftwood, or in other sheltered areas. It is not an active, open-water swimmer and will often be invisible for extended periods, particularly when first introduced to a new tank. This is entirely normal behaviour. With time and in a well-established, dimly lit tank with minimal disturbance, the fish will become bolder and more visible, particularly at feeding times.

Males will establish a small territory, typically centred on a preferred shelter or potential nest site, and will defend this area gently against other fish. Courtship involves the male displaying his full iridescent colouration with fins fully extended, approaching the female with a characteristic shimmy or lateral display. This is one of the most visually rewarding behaviours to observe in the home aquarium.

Tank Mates

Betta hendra is best kept in a species-only setup. Its specialised water chemistry requirements – extremely soft, highly acidic blackwater – immediately rule out the vast majority of commonly available tropical fish. Furthermore, its small size, shy temperament, and slow feeding habits mean it is easily outcompeted, stressed, or predated upon by more boisterous or larger tank mates. That said, a small number of species share similar environmental requirements and can coexist peacefully with Betta hendra in a sufficiently spacious, well-structured tank.

Good tank mates

Fish to avoid

Breeding

Betta hendra is a bubble-nester, constructing a small, often inconspicuous nest of air bubbles beneath a leaf, piece of driftwood, or other overhanging surface near the water surface. Breeding in captivity is achievable and is rated as moderate in difficulty, provided the correct water conditions and tank setup are in place.

To condition a pair for breeding, offer a varied diet rich in live foods – daphnia, baby brine shrimp, and grindal worms are all excellent – for two to three weeks. Ensure that water parameters are stable and within the optimal range: pH 4.0 to 5.0, temperature 24 to 26 degrees Celsius, and minimal hardness. The tank should contain ample cover and at least one potential nest site, such as a floating Indian almond leaf, a small clay pot on its side near the surface, or a piece of driftwood with an overhang.

When the male is ready to breed, he will construct a bubble nest – typically a modest affair compared to the large, conspicuous nests of Betta splendens. He will then begin to court the female, displaying with fins fully spread and body colours at their most intense. The iridescent green colouration of a displaying Betta hendra male is at its peak during courtship. The female, if receptive, will approach the nest site and the pair will engage in the typical anabantoid embrace, with the male wrapping his body around the female beneath the nest.

Eggs are released and fertilised during the embrace, and the male collects the sinking eggs in his mouth, transferring them to the bubble nest. Spawning may involve multiple embraces over the course of several hours. Clutch sizes are small, typically ranging from 20 to 50 eggs.

After spawning, the male assumes sole responsibility for guarding and tending the nest. He will retrieve fallen eggs, repair the bubble structure, and aggressively defend the nest against all intruders, including the female. It is generally advisable to remove the female after spawning to prevent her from being harassed by the male.

Eggs hatch in approximately 24 to 48 hours, and the fry become free-swimming after a further two to three days. At this point, the male’s parental duties typically cease, and he can be removed. The fry are tiny and require infusoria, paramecium, or commercially available liquid fry food as a first food for the first week or so, after which they can graduate to freshly hatched baby brine shrimp and micro worms. Growth is slow, and fry should be raised in the same soft, acidic water as the parents. Maintaining excellent water quality with frequent, small water changes using matched replacement water is critical during the rearing period.

Common Diseases

Betta hendra, when kept in appropriate blackwater conditions with stable water chemistry, is a reasonably hardy species. However, the extreme water parameters required can make disease treatment challenging, as many common aquarium medications are less effective or behave unpredictably in very soft, acidic water.

Velvet disease (Piscinoodinium pillulare, sometimes referred to as Oodinium) is one of the most common ailments encountered in wild bettas and other blackwater species. It presents as a fine, gold or rust-coloured dusting on the body and fins, often accompanied by lethargy, clamped fins, and flashing (scratching against surfaces). Velvet can spread rapidly in a warm, dimly lit tank. Treatment involves raising the temperature slightly, blacking out the tank completely to disrupt the parasite’s photosynthetic life stage, and careful use of copper-based or other anti-parasitic medications at reduced doses appropriate for soft water.

Fin rot can occur if water quality deteriorates or the fish is stressed. It presents as fraying or disintegration of the fin margins, sometimes with a whitish or reddish edge. Improving water quality through increased water changes is the primary treatment; antibacterial medications may be used in severe cases but should be dosed cautiously in soft, acidic water.

Ich (white spot disease, caused by Ichthyophthirius multifiliis) can affect Betta hendra, though it is less common in very acidic water where the parasite’s life cycle is inhibited. If it does occur, raising the temperature to 28 to 30 degrees Celsius and treating with half-dose formalin or malachite green (avoiding copper in extremely soft water if possible) is the usual approach.

Internal parasites may be present in wild-caught specimens. Quarantine of all new acquisitions is strongly recommended, along with prophylactic treatment with an appropriate anti-parasitic if internal parasites are suspected. Signs include emaciation despite feeding, white or stringy faeces, and a hollow-bellied appearance.

Prevention is far preferable to treatment in this species. Maintaining stable, appropriate water chemistry, avoiding overstocking, offering a varied diet, and minimising stress through subdued lighting and adequate cover are the best strategies for keeping Betta hendra healthy.

FAQs

Can Betta hendra be kept in a community tank?

Betta hendra is best kept in a species-only setup or with a very small number of carefully selected tank mates that share its requirement for extremely soft, acidic blackwater. Most common community fish cannot tolerate the water conditions this species needs, and more active or larger fish will stress it. A dedicated blackwater tank is strongly recommended.

Does Betta hendra need a heater?

This depends on the ambient temperature of the room where the tank is kept. Betta hendra thrives at 22 to 27 degrees Celsius. If your room temperature consistently remains within this range, a heater is not strictly necessary. However, if temperatures drop below 22 degrees Celsius, particularly overnight, a small adjustable heater should be used to maintain stability.

Why does my Betta hendra look dull and brownish?

The vivid iridescent green colouration of Betta hendra males is highly dependent on the fish’s mood, condition, and environment. Fish that are stressed, newly introduced, kept in overly bright lighting, or maintained in water that is too hard or alkaline will often appear dull and washed out. Providing soft, acidic blackwater conditions, subdued lighting, ample cover, and a high-quality live food diet will bring out the species’ full colouration over time.

How can I tell Betta hendra apart from Betta uberis?

The most reliable distinguishing feature is the dorsal-fin ray count: Betta hendra has 10 to 12 dorsal-fin rays, whereas Betta uberis has 14 to 17. However, this is difficult to verify in a live, moving fish without a clear photograph and some practice counting fin rays. In practical terms, purchasing from reputable breeders who can confirm the species identity and provenance is the most reliable approach for hobbyists.

Is Betta hendra suitable for beginners?

Betta hendra is not recommended for beginners. Its requirement for extremely soft, acidic blackwater conditions, sensitivity to water chemistry fluctuations, and preference for live foods make it a species best suited to experienced aquarists who are comfortable working with RO water, monitoring pH at low values, and culturing live food. That said, a motivated hobbyist willing to research and invest in the correct setup can certainly succeed with this species as a first wild betta.

  • Betta coccina Care Guide – The type species of the coccina group and a close relative of Betta hendra, requiring very similar husbandry and blackwater conditions.
  • Betta persephone Care Guide – Another green-iridescent member of the coccina complex, sharing Betta hendra’s distinctive colouration and conservation concerns.
  • Betta uberis Care Guide – The closest geographic relative of Betta hendra from Kalimantan, useful for understanding the differences between these two similar species.
  • Liquorice Gourami (Parosphromenus) Care Guide – Another group of small, blackwater-specialist labyrinth fish with very similar tank requirements and conservation issues.
  • Chocolate Gourami Care Guide – A popular blackwater gourami species that shares habitat preferences and can coexist with Betta hendra in appropriately sized tanks.

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