
Hillstream Loach Overview
Scientific Name: Sewellia lineolata
Origin: Fast-flowing streams in Southeast Asia, particularly China and Vietnam
Adult Size: Up to 7 cm (around 2.8 inches)
Temperament: Peaceful but territorial
Difficulty Level: Intermediate
Tank Size: 60L+
Temperature: 20–24°C
Hillstream Loaches are unique freshwater fish known for their flattened bodies, sucker-like mouths, and fascinating adaptations for life in strong currents. They are peaceful yet territorial bottom dwellers, preferring aquariums that mimic their natural fast-flowing river habitats. Hillstream Loaches are best suited to intermediate aquarists who can maintain clean, well-oxygenated water
Aquarium Requirements for Hillstream Loaches
Hillstream Loaches thrive in well-oxygenated, cool freshwater tanks with strong water movement.
Typical aquarium conditions include:
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Tank Size: 60 litres or larger recommended
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Temperature: 20–24°C
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pH Range: 6.5 – 7.5
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Filtration: Strong filtration to maintain oxygenation and gentle water flow across the substrate
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Aquarium Type: Planted or rock-heavy aquascapes with smooth stones and open surfaces for grazing
Regular water changes and careful monitoring of water parameters are essential to keep Hillstream Loaches healthy and stress-free.
Feeding
Hillstream Loaches are omnivorous, grazing primarily on algae but also consuming protein-rich foods.
Recommended diet includes:
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Algae wafers or biofilm-based foods
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Blanched vegetables such as zucchini or spinach
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Occasional live or frozen foods like daphnia or bloodworms
Feed in small portions once or twice daily, focusing on surface and rock feeding to match their natural grazing behaviour
Behaviour and Tank Mates
Hillstream Loaches are peaceful but can be territorial, particularly around feeding and resting spots.
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Temperament: Calm, bottom-dwelling, and territorial
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Tank mates: Best with other peaceful, fast-swimming fish that occupy different water levels; avoid slow-moving or long-finned species
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Social behaviour: Can be kept in small groups, but ensure sufficient space and hiding spots to reduce aggression
Their fascinating appearance and active grazing behaviour make them a captivating addition to a suitable community aquarium.
Setting Up an Aquarium for Hillstream Loaches
To provide an ideal environment for Hillstream Loaches:
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Use a tank of 60L or larger with strong oxygenation
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Include rocks, driftwood, and smooth stones to create natural grazing surfaces
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Maintain cool, well-oxygenated water with gentle currents
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Perform regular water changes to ensure excellent water quality
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Provide ample hiding spaces to reduce territorial disputes
Hillstream Loaches at Smith’s Aquatics
At Smith’s Aquatics in Stockton-on-Tees, we regularly stock Hillstream Loaches, highlighting their unique appearance and interesting behaviours.
Our team can help you with:
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Choosing healthy fish
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Planning a suitable aquarium setup
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Selecting compatible tank mates
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Advice on feeding and maintenance
If you are interested in keeping Hillstream Loaches, visit our store to speak with our aquatics team and learn more about these remarkable tropical fish.