Taxonomy & naming
Tanichthys kuehnei was described in 2019 by Bohlen, Dvořák, Thang and Šlechtová. The type locality is Rach Hoi Da stream, running from the Bach Ma Mountains to the Lang Co lagoon in Hue Province. The Catalog of Fishes (Eschmeyer, CAS) is the authority for the valid name. Tanichthys sits in Tanichthyidae, the white cloud minnows. Aquarium stock of Tanichthys from Vietnam has been mixed up between species, so the name should be used carefully.
Morphology
Tanichthys are slender, small cyprinoids with a dark lateral stripe. FishBase gives a maximum of 1 in SL. The pattern that separates this species from T. albonubes and the other Vietnamese forms is set out in the original description.
Habitat
Small streams on the eastern slope of the Bach Ma massif, running toward a coastal lagoon in central Vietnam. FishBase lists the species as freshwater and benthopelagic, known from Vietnam. These are generally clear hill streams, and measured water values have not been published.
Feeding
The diet has not been described. White cloud minnows generally take small invertebrates and plankton from near the surface and mid-water.
Mating
Courtship has not been described for this species.
Breeding
Spawning has not been described, in the wild or in captivity.
In the aquarium
White cloud minnows in general are hardy schooling fish that tolerate cool to moderate temperatures. Whether stock sold as kuehnei is correctly identified cannot be assumed. Species-specific temperature and pH ranges have not been published.
Conservation
Tanichthys kuehnei has not been assessed by the IUCN. It is known only from a small area of central Vietnam, so it should be treated as a locally restricted fish with an undocumented status. Wild-collected animals in the trade should be viewed with that in mind.