Butterfly Hillstream Loach

Geographic Origin and Biotope: Native to the Xi Jiang river basin in southern China. Inhabits exclusively fast-flowing, cold and highly oxygenated mountain streams, clinging firmly to smooth boulders in the current.

Taxonomy and Morphology: Chinese Hillstream Loach / Butterfly Pleco (Beaufortia kweichowensis). Often sold as a "pleco" or "freshwater stingray", it is actually a loach. The body is extremely flattened and the pectoral and pelvic fins form an integral elliptical suction cup to resist the current.

Social Behavior: Territorial towards conspecifics in tight spaces, but the "fights" are harmless dances in which two individuals push each other laterally ("parallel swimming"). Totally peaceful and harmless towards any other fish species.

Coloration and Sexual Dimorphism: Pale beige/golden background with an intricate pattern of blackish spots and reticulations (leopard type) extending over the entire "fan" body. Difficult to sex, but adult females seen from above are slightly thicker and less angular than males.

Aquarium Setup: "River Manifold" tank essential (min. 80 cm / 32 inches). The layout must include rounded and smooth river pebbles, very strong lighting to promote algae growth, and powerful unidirectional movement pumps (15-20 times the volume).

Diet and Feeding: Aufwuchs scraper. Survives by scraping biofilm, flat algae and microorganisms from stones. The aquarium MUST be mature and full of green algae on the stones. Accepts flaked spirulina tablets and vegetable gel, but never touches plants.

Water Quality: Cool water sub-tropical species (18-24°C / 64-75°F). The heater is not needed or is harmful. The water must be brutally oxygenated: a decrease in oxygen or a summer thermal peak above 26°C (79°F) kills them by asphyxiation.

Compatibility and Tankmates: Perfect with other Hillstream species (Sewellia, Gastromyzon), Danio rerio, Tanichthys albonubes and small stream gobies (Rhinogobius). Incompatible with classic tropical fish that require still and warm waters.

Aquarium Reproduction: Extremely rare. They lay eggs in excavations among the bottom pebbles in areas with strong current. The fry hide in the substrate feeding on micro-algae and infusoria before emerging.

Risks and Diseases: Starvation from "clean aquarium". They literally starve to death in classic warm, clean tropical community aquariums maniacally scraped by the aquarist. Green algae stones are their life insurance.