Yellow Pygmy Catfish
Yellow Pygmy Catfish (Hyalobagrus flavus) is a tiny and uncommonly available bagrid catfish from the blackwater peat swamps of Sumatra and Borneo. The pale yellowish to translucent body with faint markings and large eyes gives this fish an almost ghostly quality. At under 2 inches it is genuinely nano-sized for a catfish, and its schooling behavior — unusual in catfish — makes it a fascinating and charming addition to blackwater nano setups.
Feeding & Care Tip: Hikari Micro Pellets soaked briefly make an excellent staple — small particle size matters for this tiny species. Supplement 2–3 times per week with Hikari Frozen or Freeze-Dried Baby Brine Shrimp and Hikari Frozen Daphnia. Feed in a calm tank; this species is a slow feeder that will be outcompeted by faster fish.
Native to the Batang Hari drainage in Sumatra and the Mentaya River basin in southern Borneo, Indonesia — both blackwater peat swamp environments with extremely soft, acidic, tannin-stained water. Hyalobagrus flavus occurs in large shoals in the wild, sometimes mixed with other small schooling catfish. Tannin additions from Indian almond leaves or driftwood are strongly beneficial.
Keep in groups of at least six — this is genuinely a schooling catfish that is far more active and visible in numbers. Keep only with other nano blackwater species: small rasboras, nano tetras, Boraras species. Any active or larger fish will outcompete this shy, slow-moving species at feeding time.
A specialist fish for the dedicated blackwater nano aquarist. In a well-set-up blackwater planted tank with dark substrate, tannins, and appropriate nano companions, a school of Yellow Pygmy Catfish is a genuinely unusual and rewarding display.
Care & Ideal Parameters
| Difficulty | Moderate |
| Temperament | Peaceful — nano specialist |
| Typical Adult Size | 1.75 inches (4.5 cm) |
| Min. Group Size | 6 minimum |
| Ideal Temp | 75–82°F (24–28°C) |
| Ideal pH | 6.0–7.0 |
| Ideal GH | 1–8 dGH |
| Ideal KH | 0–4 dKH |
| Staple Food | Hikari Micro Pellets (soaked) |
| Treat / Supplement | Hikari Frozen or Freeze-Dried Baby Brine Shrimp; Hikari Frozen Daphnia |
| Origin | Sumatra and southern Borneo, Indonesia (blackwater peat swamps) |
| Notes | Genuine schooling catfish — unusual behavior for the family. Blackwater species — soft acidic water and tannins important. Slow feeder — avoid competition. Nano only — any larger fish will outcompete it. |
