Neogastromyzon is a genus of hillstream loaches (family Gastromyzontidae, the sucker-bodied loach group centered on Southeast Asian uplands) endemic to the island of Borneo - the atlas's countries are Malaysia, Indonesia, and Brunei Darussalam, all three sharing the island. Atlas species are small, 1.5–2.5 in, with the flattened, streamlined body and expanded paired fins that let hillstream loaches cling to rock faces in fast, well-oxygenated mountain and foothill streams, grazing algae and biofilm off the stone surface with a ventral suckermouth.
This is a genus of narrow specialist interest rather than a mainstream aquarium staple - Bornean hillstream loaches in general appeal to keepers running dedicated high-flow, high-oxygen stream tanks rather than standard community setups, and individual Neogastromyzon species are rarely traded outside that niche. Conservation status leans reassuring but incompletely known: 3 of the 6 atlas species are Least Concern and 1 is Near Threatened, while 2 remain Not Evaluated, consistent with how localized many Bornean stream endemics are and how little survey attention narrow island drainages typically receive.