Reticulated Hillstream Loach

The Reticulated Hillstream Loach (Sewellia lineolata) is a peaceful and highly specialized freshwater fish adapted to fast-flowing, oxygen-rich streams. It thrives in mature aquariums of at least 30 gallons designed to replicate river conditions, with strong water movement, high aeration, and smooth rock surfaces for grazing and resting. Ideal water parameters include temperatures between 68–75°F, a pH of 6.5–7.5, and very low nitrates, as this species is sensitive to poor water quality. A river-style setup with powerheads, rounded stones, and biofilm-rich surfaces is essential for long-term success. Reticulated Hillstream Loaches are constant grazers that feed primarily on biofilm and algae, but should also be supplemented with algae wafers, spirulina-based foods, blanched vegetables, and occasional frozen foods like bloodworms or brine shrimp. They are peaceful community fish best kept with other non-aggressive, fast-water species such as danios, rasboras, and other hillstream loaches. With stable, well-oxygenated conditions and a mature aquarium ecosystem, they become active, hardy, and fascinating additions that spend much of their time “clinging” to rocks and glass in flowing water.