The Bloody Mary Hillstream Loach, scientifically referred to as Gastromyzon “Red Lamandau,” is a striking and specialized freshwater species native to the fast-flowing, oxygen-rich streams of Borneo. Renowned for its vivid red coloration and intricate body patterns, this loach is a favorite among aquarists who enjoy riverine setups that showcase both visual beauty and interesting behavior. This loach has a flattened, streamlined body adapted for life in strong currents, with broad pectoral and pelvic fins that allow it to cling to rocks and move gracefully across substrates. Its body displays a bold red coloration, often accented with darker markings or subtle patterns that create a dramatic contrast against the stream-like backdrop of an aquarium. The fins may also show hints of iridescence, which catch light as the fish moves, enhancing its dynamic appearance. In the aquarium, the Bloody Mary Hillstream Loach thrives in a setup that mimics its natural environment. Smooth rocks, pebbles, and fine gravel provide surfaces for grazing, while strong water flow and high oxygen levels are crucial for its well-being. Adding driftwood, leaf litter, and hardy plants such as Anubias or Java fern creates shaded resting spots, though plenty of open rock surfaces should remain for natural movement and foraging. This species is peaceful and social, performing best when kept in small groups. Group settings encourage grazing, natural interactions, and more confident behavior. They coexist well with other calm, current-loving species such as danios, rasboras, and other hillstream loaches, making them suitable for flowing-water community tanks. Feeding focuses on their natural diet of algae and biofilm. In aquariums, this can be supplemented with sinking algae wafers, blanched vegetables like zucchini or spinach, and occasional protein foods such as frozen daphnia or bloodworms. A varied diet promotes vibrant coloration and keeps them active and healthy. Breeding Gastromyzon “Red Lamandau” in captivity is rarely documented, as it likely requires specific environmental triggers such as water flow, substrate, and seasonal cues. Most specimens in the aquarium hobby are kept for their appearance and fascinating behavior rather than for breeding. The Bloody Mary Hillstream Loach is an impressive addition to river-style aquariums. Its vivid red coloration, peaceful temperament, and specialized adaptations for life in flowing water make it a captivating species that adds both movement and striking visual interest to carefully maintained setups.