Gastromyzon viriosus (Yellow Finned Hillstream Loach)

Yellow-Finned Hillstream Loach (Gastromyzon viriosus)

Bring movement and beauty to your freshwater aquarium with the Yellow-Finned Hillstream Loach (Gastromyzon viriosus). This striking species is known for its flattened body, vibrant yellow fins, and unique “suction-cup” mouth that allows it to cling to rocks in fast-flowing streams. Perfect for well-oxygenated, high-flow aquariums, this loach adds both visual interest and functional algae control.

Product Details:

Species: Gastromyzon viriosus

Common Name: Yellow-Finned Hillstream Loach

Size: Up to 2.5 inches

Origin: Borneo

Lifespan: 5–8 years

Temperament: Peaceful, ideal for community tanks

Water Parameters:

Temperature: 68–75°F (20–24°C)

pH: 6.5–7.5

Hardness: 3–12 dGH

Tank Flow: High flow and well-aerated

Diet:

Primary Diet: Biofilm, soft algae, and algae wafers

Supplements: Blanched vegetables (zucchini, spinach), high-quality sinking micro pellets

Occasional Treats: Frozen foods like daphnia, bloodworms, or brine shrimp

Tank Requirements:

Minimum Tank Size: 20 gallons

Substrate: Smooth stones and fine gravel

Decor: Rounded river rocks, driftwood, and live plants

Filtration: Strong filtration with excellent water movement and oxygenation

Lighting: Moderate to high to support algae growth for grazing

Behavior & Compatibility:

Peaceful and social when kept in groups of 3 or more

Best with non-aggressive tank mates (small rasboras, danios, tetras, other loaches)

Will actively graze surfaces, helping control algae growth

Why Choose the Yellow-Finned Hillstream Loach?

This loach is not only stunning with its vibrant fins and active swimming style, but also plays an important role in keeping your tank clean. Their natural behavior mimics that of miniature stingrays gliding across the glass and rocks—making them a delight to watch in a properly set up river-style aquarium.

Note: Ensure your tank has high oxygen levels and strong current to keep this species healthy and active. Avoid still or poorly filtered tanks.