Tanichthys is a genus of small, slender cyprinids from southern China and northern Vietnam, and it is dominated in fame by a single species: Tanichthys albonubes, the White Cloud Mountain minnow. The atlas covers 2 species, both around 1.5 in as adults, occupying cool hill streams, with the far less common Tanichthys micagemmae restricted to a narrow range of streams in Vietnam. White Clouds are torpedo-shaped little fish with a gold-flecked lateral stripe and red-tipped fins, built for schooling in open water over cool, well-oxygenated flowing habitat rather than still ponds.
Tanichthys albonubes is one of the most widely kept freshwater aquarium fish in the world, prized for decades as a beginner-friendly, unusually cold-tolerant schooling fish that can be housed in an unheated tank and even outdoors in temperate climates during summer. Ironically, the species that stocks pet shops worldwide is now considered at serious risk in its original Guangdong wild habitat due to collection pressure and stream degradation, which is likely why both atlas species appear on the CARES conservation priority list. Tanichthys micagemmae is far more obscure, known mainly to species-focused keepers.