Yellow Finned Hillstream Loach 'Gastromyzon viriosus'

The Yellow Finned Hillstream Loach (Gastromyzon viriosus) is a rare and striking freshwater fish native to the Tatau River basin in Sarawak, Malaysia. Known for its robust, flattened body and vibrant golden-yellow fins, it is a specialist species adapted to high-flow, oxygen-rich environments.

• Scientific Name: Gastromyzon viriosus.
• Common Names: Yellow Fin Borneo Sucker, Spiny Head Borneo.
• Adult Size: Typically reaches 5–6 cm (approx. 2–2.5 inches).
• Lifespan: 3–4 years with proper care.

• Water Parameters:
  • Temperature: 20–25°C (68–77°F). They prefer cooler, stable temperatures.
  • pH: 6.0–7.5.
  • Oxygen: Critical. High surface agitation and extra powerheads are essential.
• Tank Setup: A minimum of 60–100 liters is recommended for a small group. Use smooth river stones, boulders, and driftwood where they can "crawl" and graze.
• Diet: Primarily algae and biofilm grazers. Supplement with sinking algae wafers, spirulina pellets, and occasional frozen foods like daphnia or bloodworms. Avoid high-protein diets as they can cause digestive issues.
• Behavior: Peaceful but social. They should be kept in groups of 3 to 5 or more to reduce stress and observe natural hierarchical interactions.

• Morphology: Possesses horizontally oriented fins that act as a suction cup, allowing it to cling to rocks in torrential currents.
• Sexual Dimorphism: Mature males may display noticeable tubercles on the head and have a broader head shape compared to fuller-bodied females.