Bintan Licorice Gourami (Parosphromenus sp. Bintan)

A living ember in Bintan’s blackwater: the licorice gourami slips between peat and shadow.

Bintan Licorice Gourami (Parosphromenus sp. Bintan): a jewel-like blackwater nano fish for experienced aquarists with soft, acidic water and a tannin-rich biotope.

• Water conditions: The Bintan Licorice Gourami is a true blackwater specialist and must be kept in soft, acidic water to thrive. Aim for a pH of roughly 4.0–5.5, a general hardness (GH) of 0–3 dGH, a carbonate hardness (KH) of 0–1 dKH and a low TDS of around 30–80 ppm. Temperature should be stable between 22–26°C (72–79°F). These fish are extremely sensitive to sudden shifts in pH, hardness and temperature, so mature, biologically stable aquaria are essential. Use reverse osmosis or rainwater as a base and add botanicals such as Indian almond leaves, oak leaves, alder cones and driftwood to release tannins and humic acids. Avoid bicarbonate-based buffers, crushed coral, limestone and any decor that raises KH. Filtration should be gentle and air-driven, such as a sponge filter, to maintain low flow while preserving biofilm. Ammonia and nitrite must remain at zero and nitrate should be kept very low. Slow drip acclimation is strongly recommended, and new specimens should be quarantined before introduction.
• Suitable tank mates: This is a shy, deliberate nano fish that is best kept in a species-only blackwater biotope, especially for breeding. If tank mates are desired, choose only tiny, peaceful blackwater species that will not compete aggressively for food, such as chili rasboras (Boraras brigittae), Phoenix rasboras, dwarf pencilfish or similarly calm nano fish. A few small dither fish can increase confidence, but too many active tank mates may cause stress and hiding. Avoid boisterous barbs, large rasboras, Bettas, other gouramis, cichlids, predatory fish and any species that feeds rapidly or nips fins. Bottom-dwelling fish that disturb leaf litter are best avoided. Small Caridina shrimp may coexist in a well-planted setup, but very small shrimp or fry could be at risk. Snails are generally tolerated but are not necessary. In groups, provide plenty of visual barriers and caves because males can be territorial when spawning.
• Feeding habits: Bintan Licorice Gouramis are micropredators with a strong preference for live and frozen foods. They often ignore or reluctantly accept dry foods, so a varied diet of baby brine shrimp, daphnia, moina, cyclops, microworms, Grindal worms, vinegar eels and small rotifers is ideal. Feed two to three very small portions daily, only as much as the fish can clear within a few minutes. Overfeeding is a serious risk in low-flow blackwater aquaria because uneaten food quickly degrades water quality. Offer a rotating variety to support condition, colour and breeding behaviour. Newly imported or shy specimens may need live foods to initiate feeding. If using frozen foods, thaw and rinse them before feeding. Freeze-dried foods can be used occasionally but should be soaked first. Avoid large, hard pellets that the fish cannot swallow.
• Care requirements: This species is not recommended for beginners because it demands stable, very soft and acidic water, careful feeding and a mature aquarium. A pair or small trio can be kept in a tank of around 30–45 litres, but larger footprints are easier to keep stable. Provide dense planting with Java moss, Cryptocoryne species, floating plants and plenty of shaded hiding places. Add caves in the form of coconut shells, PVC tubes, ceramic caves and leaf litter, as licorice gouramis are cave spawners. Lighting should be subdued to mimic the blackwater biotope. Maintain a tight-fitting lid because anabantoids can jump. Perform small, regular water changes of around 10–20% weekly using water matched to the aquarium’s pH, hardness and temperature; avoid large water changes that cause parameter swings. Keep the filter gentle and clean it only in tank water to preserve beneficial biofilm. Avoid copper-based medications and treat any health issues cautiously. Breeding is possible in dedicated setups: the male typically guards the cave and eggs, and fry require infusoria, vinegar eels and microworms before moving on to larger foods. Always choose captive-bred stock where possible, and never release this fish into the wild.