The Hillstream Loach (Sewellia lineolata and related species) is a small, peaceful bottom-dwelling fish adapted to life in fast-flowing, oxygen-rich mountain streams. Its flattened body and sucker-like fins allow it to cling to rocks in strong currents, making it well-suited to aquariums with powerful filtration, high oxygen levels, and smooth stones. Hillstream Loaches primarily graze on algae and biofilm but should also be offered sinking wafers, spirulina-based foods, blanched vegetables, and occasional protein-rich treats like bloodworms. They thrive in cooler, clean water and are best kept in groups of three or more, where they display natural social behaviors. Due to their specific need for strong flow and pristine conditions, they are best suited for experienced aquarists who can provide a river-tank style setup.
Parameter
Requirement
Scientific Name
Sewellia lineolata (and related species)
Tank Size
Minimum 30 gallons
Temperature
20–25°C (68–77°F)
pH Range
6.5–7.5
Water Hardness
Soft to moderate (5–12 dGH)
Flow & Oxygenation
Strong current, high oxygenation essential
Diet
Algae, biofilm, spirulina flakes, sinking wafers, blanched vegetables, occasional live/frozen foods
Temperament
Peaceful, suitable for community tanks with non-aggressive species
Social Behavior
Best in small groups (3+)
Breeding
Possible in aquariums with strong flow and caves; males guard eggs
Lifespan
5–8 years with proper care