Taxonomy & naming
Schistura moeiensis was described by the Swiss ichthyologist Maurice Kottelat in 1990. It belongs to Nemacheilidae, the stone or brook loaches, by far the largest family in the loach superfamily Cobitoidea and one that has been repeatedly reshuffled as older catch-all genera such as Nemacheilus and Noemacheilus were split apart. The Catalog of Fishes, the standing authority for valid fish names, places this species in Schistura, the most species-rich genus of the family, and there is no indication in the available sources that it was ever placed under a different generic name.
The species epithet moeiensis refers to its type locality, the Mae Nam Moei — the river that forms much of the Thailand-Myanmar border and feeds into the Salween — marking this as one of many Schistura named directly for the single stream in which it was collected.
Morphology
Schistura moeiensis is a small, slender stone loach, reaching only about 2 in in standard length. Like other members of its genus it carries the small, erectile suborbital spine typical of true loaches, tucked into a groove below the eye, along with the near-scaleless, thin skin shared across Nemacheilidae — a detail that matters for anyone handling or medicating the species, since scaleless loaches absorb dissolved compounds readily. FishBase reports no sexual dimorphism has been documented for this species.
Beyond size and family-typical spine and skin traits, detailed morphological description is sparse in the sources available; this is a data-sparse species known chiefly from survey records rather than a dedicated taxonomic or aquarium literature.
Habitat
This species is known only from the Mae Nam Moei drainage, a tributary of the Salween River on the Thailand-Myanmar border — its type locality and, as far as recorded, the only place it has been collected. It lives in streams with moderate to fast current, over riffles and a gravel-to-stone substrate, though some records note muddier or sandy stretches with gastropod shells present. Depths recorded range from very shallow water down to about 34 ft, consistent with a fish that uses a range of stream microhabitats rather than a single narrow niche.
This is a cool-to-moderate, well-oxygenated, flowing freshwater habitat — the kind of clear hill-stream setting typical of Schistura generally — not a warm, still or blackwater environment.
Feeding
FishBase lists a trophic level around 3.0, consistent with a benthic invertebrate feeder. Like the great majority of Schistura, this species is best understood as a micro-predator that works the streambed for small aquatic invertebrates — insect larvae, worms and similar prey — rather than as an algae grazer or omnivore in the botiid mould.
No aquarium feeding data exists for this species specifically, but on the strength of its trophic position and its close relatives, a diet of small sinking live, frozen or prepared foods that mimic benthic invertebrates would suit it far better than flake.
Mating
Documentation is very limited. FishBase notes a single record of a ripe female, 2 in standard length, carrying ova about 0.5 in in diameter — the only direct evidence of reproductive biology available for this species. No description of courtship, spawning site selection or seasonal triggers has been recorded.
Given the near-total absence of aquarium or field observation, nothing more specific can honestly be said about mating behaviour in this species without speculating beyond the source material.
Breeding
As with the great majority of stone and brook loaches, Schistura moeiensis is not known to have been bred in the aquarium, and field data on its reproduction is limited to the single gravid female noted above. Nemacheilid loaches in general are egg-scatterers that release eggs over gravel and among stones in flowing water, without nest-building or parental care of any kind — there is no cave-guarding or mouthbrooding behaviour anywhere in this family.
Given the single-locality range and the complete absence of hobby or captive-breeding records, the honest summary is that this species is essentially unknown in captivity and should be assumed unbred at home.
In the aquarium
Schistura moeiensis is not established in the aquarium trade, and no husbandry record for the species appears to exist. It is included here for completeness as a documented member of Nemacheilidae rather than as a species a keeper is likely to encounter for sale.
Were it ever kept, its biology points clearly to the needs shared by cool-water Schistura generally: strong water flow, high dissolved oxygen, a gravel-to-stone substrate, and clean, well-filtered water rather than a warm, still community tank. As a near-scaleless true loach it would be expected to share the group's sensitivity to copper-based medications and full-strength treatments, and its small adult size (barely over 2 in) means it would need correspondingly modest but well-oxygenated quarters, not a large showpiece tank.
Conservation
Schistura moeiensis is assessed by the IUCN as Data Deficient, an assessment dated 2011. That status fits a species known only from a single tributary system on the Thailand-Myanmar border, where survey effort has been limited and population trends have not been established.
With no aquarium trade and no documented commercial pressure, the main conservation relevance of a fish like this is as an indicator of the broader problem facing narrow-range Salween-basin endemics: a great many Schistura are known from one stream, and habitat change anywhere in that single drainage could affect the entire known population before enough is understood to assess the real risk.