Reticulated Hillstream Loach

About

The reticulated hillstream loach (Sewellia lineolata) is one of the more characterful members of the gastromyzontid family, native to fast-flowing streams and riffles across Vietnam, Cambodia, and southern China, including the Mekong basin. Its flattened body, horizontally splayed paired fins, and a specialized pelvic structure combine into a powerful suction disc, letting it cling to rocks in powerful currents. Adaptations that are immediately obvious when you watch one navigate a tank. The body is marked with three to five dark longitudinal stripes, which makes identification straightforward and sets it apart from its closest relative, the spotted S. speciosa. In the aquarium this species is confident and assertive, more dominant than most other hillstream loaches, and males in particular will defend prime feeding territories with entertaining belly-to-belly standoffs. It works best in groups of six or more, which distributes that territorial energy and brings out natural social behavior. Tankmates should be chosen with care. Small, active midwater fish like danios and rasboras work well, as do rheophilic gobies and catfishes, but similarly shaped benthic species often struggle to compete. Current flow and a well-structured layout are important, and intermediate-level care experience will serve you well. One genuine highlight: this species breeds more readily in captivity than almost any other loach.