Parosphromenus anjunganensis – Parosphromenus anjunganensis

Among labyrinth fishes, few species are as intriguing and mysterious as Parosphromenus anjunganensis. This delicate gourami from blackwater habitats captivates advanced aquarists with its subtle beauty, fascinating behaviour, and demanding care requirements. Understanding its natural environment, social dynamics, and specific needs is essential for any fishkeeper who wishes to succeed with this rare and valuable species.

Origin and natural habitat of Parosphromenus anjunganensis

Parosphromenus anjunganensis belongs to the genus Parosphromenus, often called licorice gouramis due to their elongated shape and dark, contrasting patterns. This species originates from peat swamp forests in Borneo, where the water is extremely soft, acidic, and heavily stained by tannins from decaying leaves and wood. These are classic blackwater biotopes, almost tea-coloured, with very low mineral content and subdued light.

In its natural environment, Parosphromenus anjunganensis inhabits shallow, slow-moving streams, forest puddles, and flooded leaf litter zones. The water is often just a few tens of centimetres deep, with dense vegetation overhead. The substrate is covered with a thick layer of leaves and branches, which creates countless hiding places and microhabitats. This context is crucial to understanding why the species is sensitive to strong currents, bright lighting, and fluctuating water parameters in the aquarium.

Temperatures in its natural biotope typically range from 24 to 28°C, while pH values can be extremely low, often between 3.0 and 5.0. Conductivity is also minimal, reflecting the almost complete absence of dissolved minerals. Such extreme conditions make Parosphromenus anjunganensis a specialist that does not adapt well to standard community aquarium setups. To recreate these conditions at home, aquarists need suitable aquariums, filtration systems, and water treatment methods, many of which are available in the range of aquarium equipment offered by MB Store.

Appearance and sexual dimorphism

At first glance, Parosphromenus anjunganensis might seem modest compared to brightly coloured community fish. Adult size typically does not exceed 3–3.5 cm, giving it a very delicate and elongated silhouette. The background colour of the body is dark brown to blackish, sometimes with a subtle metallic sheen. What makes this fish truly remarkable are the contrasting iridescent markings that appear especially vivid during displays and courtship.

Males usually exhibit more intense colours and stronger patterns than females. Their fins often display bluish, turquoise, or greenish metallic lines, combined with lighter bands and dark margins. During courtship, males can darken even more, making the iridescent colours stand out dramatically against the black body. Females tend to be slightly smaller and fuller-bodied, with less intense colours but still attractive in their own right.

The caudal fin in Parosphromenus anjunganensis often shows distinctive light and dark banding, while the anal and dorsal fins may have subtle but very elegant edging. The eyes are relatively large, giving the fish a characteristic curious expression. Because of their small size and dark coloration, these fishes are far more impressive in a carefully designed aquascape with subdued lighting than in a brightly lit, sparsely decorated tank.

Setting up the ideal aquarium for Parosphromenus anjunganensis

Successfully maintaining Parosphromenus anjunganensis starts with an appropriate aquarium design. Although the species is small, it demands a stable environment with pristine water. A tank of 40–60 litres is often recommended for a small group or pair, allowing enough space for territories while maintaining manageable water chemistry. Smaller dedicated breeding tanks are possible for experienced keepers, but stability is easier to achieve in slightly larger systems.

Substrate should be dark and fine, such as sand or very fine gravel, to mimic natural conditions and reduce stress. A thick layer of leaf litter—Indian almond leaves, oak, beech, or other safe dried leaves—provides hiding places, releases tannins, and fosters microfauna that can serve as supplemental food. Pieces of driftwood and small roots add structure and create shaded zones, which these shy fish appreciate.

The filtration system should offer gentle water movement. Sponge filters or small internal filters with flow reduced to a minimum are often ideal. Strong currents not only stress Parosphromenus anjunganensis but can also disturb delicate territories and bubble nests if the species exhibits nest-building behaviour. MB Store offers a selection of filters, heaters, and other specialised equipment suitable for creating low-flow, stable environments tailored to sensitive species like this one.

Lighting must be moderate to low. Bright light can cause these fish to hide constantly and show less colour. Floating plants such as Salvinia, Pistia, or Limnobium are excellent for dimming the light and providing a sense of security. They also help to stabilise the water chemistry by absorbing nutrients. When combined with dark substrate and leaf litter, the result is a calm, natural-looking aquarium where Parosphromenus anjunganensis will feel at home.

Water parameters and blackwater chemistry

Maintaining suitable water parameters is probably the most critical aspect of keeping Parosphromenus anjunganensis. This species truly thrives only in very soft, acidic water. Aim for a pH between 3.5 and 6.0, with 4.0–5.5 being a good compromise for captive conditions. General hardness (GH) should be extremely low, ideally below 3°dGH, and carbonate hardness (KH) almost zero. Conductivity values under 100 µS/cm are often recommended.

To achieve such conditions, many aquarists use reverse osmosis (RO) water or demineralised water as a base, then adjust it with natural acids (such as humic and fulvic acids from peat or leaf litter) rather than mineral additives. MB Store can provide RO units, digital meters, and other testing equipment to help you precisely monitor and control your water chemistry. Regular testing of pH, conductivity, and temperature is essential, especially in smaller tanks where fluctuations occur more quickly.

Creating a true blackwater environment involves more than just lowering the pH. Adding botanicals—leaves, alder cones, seed pods, pieces of driftwood—gradually releases tannins and beneficial compounds. The water will take on a dark amber or tea colour, which might seem unusual to beginners but is ideal for Parosphromenus anjunganensis. These conditions can also inhibit certain pathogens and reduce stress, contributing to the long-term health and well-being of the fish.

Water changes should be frequent but gentle. Because the water is so soft and the buffering capacity minimal, large or abrupt changes can cause rapid pH swings that are dangerous for the fish. A good strategy is to perform small changes of 5–10% several times a week, using pre-conditioned water that closely matches the aquarium parameters in temperature and chemistry. Patience and stability are much more important than aggressive maintenance in this type of setup.

Feeding and nutrition

Parosphromenus anjunganensis is a micropredator by nature, feeding on tiny aquatic invertebrates, insect larvae, and other small organisms drifting in the water column or crawling among the leaf litter. In the aquarium, they often show a strong preference for live foods and may reject standard dry flakes or pellets, especially at first. Providing appropriate nutrition is therefore another key challenge for keepers.

Suitable live foods include microworms, freshly hatched Artemia nauplii, grindal worms, and small Daphnia or cyclops. Frozen foods such as cyclops, fine daphnia, and high-quality bloodworms can also be accepted, although care must be taken to match the mouth size of these tiny fish. Overly large prey items can cause choking or digestive issues. Offering food in small portions multiple times per day helps ensure that the fish can feed comfortably without fouling the water.

For aquarists who wish to reduce dependence on live foods, training Parosphromenus anjunganensis onto high-quality frozen diets is a realistic goal. Some individuals may also accept finely crushed, premium micro-pellets, though this is less common. As with many specialised species, variety is essential. Rotating between different food types promotes balanced nutrition, supporting immune function, coloration, and reproductive success.

Because these fish are sensitive to poor water quality, uneaten food must be removed promptly. Light feeding and careful observation during meals are crucial. It is far better to underfeed slightly than to allow food to decompose in a low-buffer blackwater system. With time and consistent routines, experienced aquarists learn how much their group can consume within a few minutes, optimising both fish health and water quality.

Social behaviour, tankmates, and compatibility

Parosphromenus anjunganensis is generally peaceful but can show subtle territorial behaviour, especially during breeding periods. Males may claim small areas around chosen spawning sites, such as a leaf cave or small structure under a root. Aggression is usually limited to displays, chasing, and occasional short skirmishes, but because of the species’ delicate nature, even minor stress can weaken individuals over time.

For this reason, many dedicated keepers prefer species-only tanks for Parosphromenus anjunganensis. A small group of one male with several females or a loosely formed colony can work well in a suitably structured aquarium. This allows natural behaviours to emerge while minimising competition with other species. Observing courtship, displays, and subtle interactions among conspecifics is often more rewarding than mixing them in a general community tank.

If you decide to house them with other fishes, choose tankmates very carefully. Ideal companions are extremely peaceful, small, and adapted to similar soft, acidic blackwater conditions. Some small rasboras, Boraras species, or tiny loaches from comparable habitats can be considered, but always introduce them cautiously and monitor their impact on behaviour and feeding. Avoid any species that is boisterous, fast-swimming, or significantly larger, as such fish may outcompete Parosphromenus anjunganensis for food or cause chronic stress.

Because this gourami prefers calm environments, avoid high densities and overstocking. A lightly stocked, carefully aquascaped tank is much more suitable than a busy community setup. This also aligns with the delicate water chemistry requirements: fewer fish produce less waste, making it easier to keep parameters within the optimal range. With the right balance, you can create a tranquil, natural-looking aquarium in which Parosphromenus anjunganensis becomes the subtle but fascinating focal point.

Breeding Parosphromenus anjunganensis in the aquarium

Breeding Parosphromenus anjunganensis is considered a challenging but highly rewarding project. Success not only provides the satisfaction of observing complex spawning behaviours but also contributes to conservation by reducing pressure on wild populations. Many Parosphromenus species face habitat loss, and captive breeding can help maintain stable lines in the hobby.

To encourage spawning, start with a well-conditioned pair or small group in a dedicated breeding aquarium. The setup should replicate the main tank’s conditions but may be slightly smaller and more controlled. Provide numerous hiding spots and potential spawning sites, such as small caves, upturned half-coconut shells, narrow tubes, and leaves forming natural shelters. Subdued lighting and dense cover are crucial, as these fish feel more secure when hidden.

The male typically chooses a site and performs courtship displays to attract the female. He may darken his colouration and show off his iridescent fins while gently guiding the female towards the nest or chosen area. Spawning often occurs under a leaf or in a small cavity, where eggs are carefully placed and fertilised. The male usually assumes primary care of the eggs, guarding them and sometimes tending a small bubble nest, depending on behavioural variation within the species.

Once the eggs hatch, the fry remain near the spawning site until they become free-swimming. At this stage, extremely fine live foods such as infusoria, rotifers, or specialized fry feeds are necessary. Many breeders prepare infusoria cultures or rely on the microfauna living in well-established leaf litter to provide first foods. As the fry grow, they can gradually transition to newly hatched Artemia and microworms.

Breeding requires exceptionally clean, stable water with no sudden parameter shifts. Even minor disturbances can cause egg or fry losses. Gentle filtration, minimal surface agitation, and very careful water changes are critical. Because of these challenges, breeding Parosphromenus anjunganensis is often undertaken by committed enthusiasts, but with proper preparation and equipment—much of which can be sourced from MB Store—success is achievable and incredibly satisfying.

Role of Parosphromenus anjunganensis in advanced fishkeeping

Parosphromenus anjunganensis occupies a special niche in the aquarium hobby. It is not a beginner’s fish; instead, it appeals to aquarists seeking to recreate authentic biotopes and explore the subtleties of fish behaviour under near-natural conditions. Keeping this species successfully demonstrates a high level of understanding of water chemistry, filtration, and the biological balance of low-mineral systems.

Licorice gouramis, including Parosphromenus anjunganensis, also raise awareness about the conservation of peat swamp forests and blackwater ecosystems. By attempting to replicate these habitats at home, fishkeepers inevitably learn more about the environmental pressures affecting them—deforestation, drainage, pollution, and climate change. This knowledge can inspire more responsible collecting, support for conservation projects, and thoughtful purchasing from suppliers who prioritise sustainable sourcing.

From an aesthetic standpoint, Parosphromenus anjunganensis is the ideal centrepiece for a specialised nano blackwater tank. Rather than relying on bright colours and constant activity, the appeal lies in quiet observation: the sudden flash of metallic fins during a display, the careful exploration of leaf litter, the subtle interactions among individuals. For many aquarists, this slower, more contemplative style of fishkeeping becomes a deeply rewarding aspect of the hobby.

MB Store supports such advanced projects by offering a wide range of aquarium equipment suitable for blackwater setups: precisely adjustable heaters, gentle filters, RO systems, water testing instruments, and appropriate aquariums in various sizes. With the right tools and careful planning, you can create an environment where Parosphromenus anjunganensis not only survives but truly thrives, revealing its full behavioural and visual potential.

Practical tips for long-term success

To summarise the key points for maintaining Parosphromenus anjunganensis, several practical guidelines can significantly improve your long-term success. Begin with a dedicated tank that prioritises stability over volume. A well-cycled, mature aquarium is mandatory; this species should never be added to newly established systems. Ensure that all decor, substrate, and leaves are aquarium-safe and thoroughly prepared before use to avoid unwanted contaminants.

Invest in reliable measuring tools such as pH meters, conductivity meters, and thermometers to monitor conditions accurately. Blackwater tanks can appear visually “dirty” due to dark water, but this colour is not an indicator of poor quality. Parameters must be tested objectively, rather than guessed. MB Store’s selection of testing kits and electronic meters can help you maintain consistent conditions and react early to any negative trends.

When adding new fish, acclimate them very slowly. Drip acclimation over an extended period is highly recommended because the difference between transport water and your delicately balanced system can be considerable. Sudden shifts in pH or hardness are among the main causes of mortality in Parosphromenus species. After introduction, keep lights low and disturbances minimal for several days, allowing the fish to settle in gradually.

Finally, approach the keeping of Parosphromenus anjunganensis with patience and respect for its specialised requirements. This is not a species that will forgive shortcuts or rushed setups. However, for aquarists willing to invest time, research, and appropriate equipment, it offers a unique window into the fascinating world of blackwater labyrinth fishes. With thoughtful planning and the right support from resources such as MB Store, your aquarium can become a living showcase of one of the most delicate and extraordinary gouramis in the hobby.

FAQ – Parosphromenus anjunganensis in the aquarium

Is Parosphromenus anjunganensis suitable for beginners?
Parosphromenus anjunganensis is not recommended for beginners. It requires very soft, acidic blackwater, extremely stable parameters, and a diet rich in live or frozen foods. These demands make it more appropriate for experienced aquarists who already have practice with sensitive species and advanced water chemistry control.

What tank size is best for Parosphromenus anjunganensis?
A tank of 40–60 litres works well for a small group or pair. While the fish are tiny, the extra volume helps maintain stable water conditions and provides space for territories. Dedicated breeders sometimes use smaller spawning tanks, but for general care, a slightly larger, well-structured aquarium is safer and more forgiving.

Can I keep Parosphromenus anjunganensis in a community aquarium?
Community setups are possible but not ideal. This species does best in species-only tanks or with a few extremely peaceful, small fish that share the same blackwater requirements. Boisterous or fast-feeding tankmates easily outcompete them for food and cause chronic stress, which often leads to poor health and shortened lifespan.

What should I feed Parosphromenus anjunganensis?
Offer mainly small live and frozen foods: Artemia nauplii, microworms, grindal worms, cyclops, and fine daphnia. Some individuals may accept high-quality micro-pellets, but live food remains crucial, especially initially. Feed small portions several times a day and remove leftovers to prevent water quality issues in the soft, weakly buffered environment.

How can I create proper blackwater conditions?
Use RO or demineralised water as a base, keep hardness very low, and gently acidify with botanicals like leaves, alder cones, and driftwood. Aim for pH around 4.0–5.5 and minimal conductivity. Let the tank mature with leaf litter, perform small but regular water changes, and monitor parameters closely using reliable test equipment.