Taxonomy & naming
Barbatula dsapchynensis was described by Alexander M. Prokofiev in 2016 in the Journal of Ichthyology, in a paper revising the loaches of the genus Barbatula (subfamily Nemacheilinae) from the Zavkhan River basin of western Mongolia. It belongs to the family Nemacheilidae, the stone or brook loaches — by species count the largest family of loaches, with roughly 790 species spread across Eurasia and a single outlying African genus.
The species epithet dsapchynensis references "Dsapchyn," an older place name for the Zavkhan River basin where the species was collected, tying the name directly to its home water. Prokofiev's revision described several closely related Barbatula from the same drainage system, among them B. dsapchynensis's closest relative, B. karabanowi, and its sympatric congener B. conilobus. As with much of Nemacheilidae, older literature and databases may still carry these fish under the broader historical genus names Nemacheilus or Noemacheilus; the current, valid combination under the Catalog of Fishes is Barbatula dsapchynensis.
Morphology
No detailed morphological description or size data for Barbatula dsapchynensis is available from the sources consulted; the species is known essentially only from its original description. As a member of Barbatula it can be expected to share the genus's general build: a small, elongate, near-scaleless stone loach with a rounded head, a pair of barbels around the mouth used to feel out food on the streambed, and the erectile suborbital spine found throughout its wider superfamily. The closely related European stone loach, B. barbatula, tops out around 4.5 in, and B. dsapchynensis is presumed to be of similar or smaller size, but no confirmed maximum length has been published for it — this figure is left unstated rather than guessed at.
Habitat
Barbatula dsapchynensis is endemic to the Zavkhan River basin, part of the Great Lakes Depression of western Mongolia — an internally drained system of rivers and lakes on the Central Asian steppe, far from any ocean. Stone loaches in this genus are stream specialists, characteristically found over gravel and stone substrate in cold, fast-flowing, well-oxygenated water, and this species occurs in the same watercourses as its sympatric relative B. conilobus.
No aquarium-relevant temperature or pH figures have been published for this species specifically. Given its high-elevation Central Asian range and its genus's general ecology, it should be treated as a coolwater to cold-water stream fish rather than a warm tropical one — closer in requirements to a temperate brook loach than to the warm, soft blackwater favoured by many tropical loaches.
Feeding
No specific dietary data has been published for Barbatula dsapchynensis. By family and genus, Nemacheilidae stone loaches are bottom-dwelling micro-predators, using their barbels to probe gravel and sediment for small aquatic invertebrates — insect larvae, tiny crustaceans and worms — in fast, clear stream water. There is no reason to expect this species differs from that general pattern, though it has never been kept or fed in captivity to confirm it.
Mating
Nothing has been published on the reproductive behaviour, seasonality or sexual dimorphism of Barbatula dsapchynensis. The species has no known aquarium or captive-breeding history. What can be said follows from its family: Nemacheilidae stone loaches typically reproduce by scattering eggs over gravel in flowing water, without pairing behaviour or nest-building, and dimorphism across the genus tends to be subtle at best. None of this has been confirmed for B. dsapchynensis itself.
Breeding
Barbatula dsapchynensis has no recorded breeding history in the aquarium — it is not known to be kept in the hobby at all. Based on the general pattern for stone and brook loaches (Nemacheilidae), the expected mode is an egg-scatterer over gravel or among stones in fast water, with no parental care. As with the rest of this family, home spawning is rare to nonexistent even for well-known species, and for a narrow-range, recently described Mongolian endemic like this one there is no captive-breeding record whatsoever. The honest statement is simply that breeding data is sparse to absent.
In the aquarium
Barbatula dsapchynensis is not established in the aquarium hobby; no keeper accounts, sizing guidance or care profiles exist for it. It should not be sought as an aquarium fish — it is a narrow-range wild population known from a single Mongolian river basin, and any specimen in trade would represent an unsustainable draw on a tiny, undocumented population. For keepers interested in the genus generally, Barbatula species are near-scaleless and, like other loaches, sensitive to copper and full-strength medications; they favour cool, fast, highly oxygenated water over a gravel or stone substrate rather than the warm, still setups suited to many tropical fish.
Conservation
Barbatula dsapchynensis has not been assessed on the IUCN Red List and carries no formal conservation status; it is recorded here as Not Evaluated rather than assigned a guessed category. As a narrow-range endemic restricted to the Zavkhan River basin in the Great Lakes Depression of western Mongolia, it is inherently vulnerable to any degradation of that single drainage system, but no population trend or threat assessment has been published. It has no presence in the aquarium trade, so trade pressure is not a documented concern; the priority for a fish like this is simply that its home water be studied and protected before any formal assessment can even be made.