Filament Licorice Gourami (Parosphromenus filamentosus) is one of the more dramatically marked licorice gouramis, named for the striking filamentous extensions on the dorsal and caudal fins of the male. The body displays bold dark banding on a pale base, and the fins take on iridescent blue and red tones during display — a spectacular sight in a properly set up blackwater aquarium. Native to peat swamp forests and slow blackwater streams of Sumatra, Indonesia, it belongs to the Parosphromenus genus: a group of miniature labyrinth fish prized among specialists for their extraordinary colors and fascinating behavior, and critically imperiled in the wild due to widespread destruction of their peat swamp habitat.
⚠ Conservation Note: Most Parosphromenus species, including P. filamentosus, are listed as Endangered or Critically Endangered on the IUCN Red List. Peat swamp forests of Sumatra are among the most rapidly disappearing habitats on Earth. Captive keeping and breeding of these fish is a meaningful contribution to their conservation. The Parosphromenus Project (parosphromenus-project.org) connects keepers, breeders, and researchers working to preserve these extraordinary fish.
Like all licorice gouramis, Parosphromenus filamentosus requires a very specific setup to thrive. It is native to blackwater environments with extremely soft, acidic water — pH 4.5–6.5, GH below 5, minimal hardness and alkalinity. The aquarium must replicate these conditions: tannin additions from Indian almond leaves, dried leaves as substrate cover, driftwood, very subdued lighting, and a mature, stable, well-established tank. They are sensitive to water quality and will not tolerate ammonia, nitrite, or sudden parameter changes. Do not attempt to keep these fish in typical community water conditions.
Best kept as a pair or small group in a species-specific setup of 10 gallons or larger. Males are territorial with each other but generally non-aggressive toward females or other species outside their size range. The full vivid coloration and fin display of the male is only seen in a calm aquarium with appropriate water conditions — fish kept in the wrong conditions typically remain pale and stressed. Provide small cave structures (bamboo tubes, coconut shells, ceramic cave ornaments) as spawning sites. Males establish and defend a cave and perform elaborate, highly colorful courtship displays toward females.
Cave spawners — the male courts the female with spectacular fin flaring and iridescent color display inside or near the chosen cave. Eggs are attached to the cave ceiling and guarded by the male. Soft, very acidic water is critical for egg development and fry survival. The fry are tiny and require infusoria or freshly hatched baby brine shrimp as first foods. Successful captive breeding of Parosphromenus species is a meaningful and worthwhile achievement — these fish are difficult to maintain as a wild population and every established captive breeding group matters.
Feeding & Care Tip: Hikari Micro Pellets (soaked), Hikari Frozen Baby Brine Shrimp, Hikari Frozen Daphnia, and Hikari Frozen or Freeze-Dried Tubifex Worms form the core diet. Live baby brine shrimp and live Daphnia are particularly effective for newly arrived or reluctant feeders. Feed small amounts 2–3 times daily. These are slow, deliberate feeders — never mix with boisterous or fast-moving fish that will outcompete them for food.
| Difficulty | Advanced — blackwater specialist |
| Temperament | Peaceful — species-specific or near-species setup required |
| Typical Adult Size | 1.5 inches (3.8 cm) |
| Min. Group Size | Pair or small group — species tank |
| Minimum Tank Size | 10 gallons |
| Ideal Temp | 75–82°F (24–28°C) |
| Ideal pH | 4.5–6.5 (best color and breeding below 6.5) |
| Ideal GH | 0–5 dGH — very soft water essential |
| Ideal KH | 0–2 dKH |
| Staple Food | Hikari Micro Pellets; Hikari Frozen Baby Brine Shrimp; Hikari Frozen Daphnia; Hikari Frozen Tubifex Worms |
| Treat / Supplement | Live baby brine shrimp; live Daphnia or Moina (best option for reluctant feeders) |
| Origin | Sumatra, Indonesia |
| Notes | Named for the filamentous fin extensions of the male. Requires blackwater conditions — soft, acidic, tannin-stained. Add Indian almond leaves and driftwood. Cave spawner; provide bamboo tubes or small ceramic caves. Endangered in the wild. Parosphromenus Project: parosphromenus-project.org |
Inventory Accuracy
If this item is at low stock, or you are ordering all or almost all of our current inventory, there may be an inventory discrepency. We will contact you about any issues as soon as possible.
Order Processing
Please allow 24 to
48 hrs to process your order. Expect an
email within 48 hrs to let you know your order is on your way.
Store Pickup
If you choose “Pickup
in Store” at checkout, an email will be sent when your order is ready for
pickup. Orders can be picked up during
store hours, see our home page for our current hours. The pick up address is 6637 Easton Rd,
Pipersville, PA 18947
Domestic Shipping Rates
Shipping charges, if
any, for your order will be calculated and displayed at checkout.
