Niwaella is a small genus of true loaches (family Cobitidae) native to China, closely related to other spined loaches in the group. Like its relatives, it is a slender, bottom-dwelling fish with barbels around the mouth for locating food in sediment and a small erectile spine beneath the eye used for defence. The atlas covers 2 species, Niwaella longibarba and N. xinjiangensis; reliable size data for the genus are sparse, and neither species has yet been evaluated by the IUCN, so both carry a Not Evaluated status.
Niwaella species are essentially unknown in the aquarium trade and are of primarily scientific and regional interest as part of China's freshwater loach fauna. Without established aquarium records or a formal IUCN assessment for either species, the atlas can say little more with confidence beyond their taxonomic placement and Chinese range - this is a genus where the honest summary is that data are sparse rather than guessing at care requirements or population trends.