Taxonomy & naming
Schistura yingjiangensis was described by Zhu in 1982, with its type locality on the Daying River near Hehua township in Tengchong County, Yunnan Province, China. Like many species originally placed in the old, broadly-defined genus Nemacheilus (or Noemacheilus), it has since been reassessed: a 2012 revision by Maurice Kottelat moved it into Schistura, and that combination now appears in some taxonomic treatments. This article follows editorial convention in retaining the original genus, Nemacheilus, while noting the shift here for the record.
It belongs to the family Nemacheilidae, the stone or brook loaches — by species count the largest family in the loach superfamily Cobitoidea, and a group whose genus-level boundaries (Nemacheilus, Schistura, Triplophysa, Barbatula and others) continue to be revised as new material and molecular data accumulate. The species epithet, yingjiangensis, refers to Yingjiang County in Yunnan, the district encompassing its known range.
This fish was long listed as Nemacheilus yingjiangensis; Eschmeyer's Catalog of Fishes places the species in Schistura, and the current combination Schistura yingjiangensis is followed here.
Morphology
As with most members of Nemacheilidae, Schistura yingjiangensis is a small, elongate, cylindrical loach built for holding position on the bottom of fast-flowing streams. Detailed morphometric data for this particular species is sparse in the available literature, and a confident maximum size figure cannot be given from the sources at hand — the typical range for small nemacheilids of this kind runs roughly 2–3.1 in, but that should be read as a family-level estimate rather than a documented figure for this species specifically.
Stone loaches of this genus typically carry the small, erectile suborbital spine found throughout Cobitoidea, along with the near-scaleless or fine-scaled skin that makes the whole loach group sensitive to medication. Where the record is silent on a specific detail for S. yingjiangensis, it is best treated as data sparse rather than assumed from the wider family.
Habitat
This species is a narrow-range endemic, known from the Daying River and the Longchuanjiang River, both tributaries of the Irrawaddy River system in Yingjiang County, Yunnan Province, China. It occupies cool, fast-flowing, well-oxygenated stream water typical of the region's benthic-pelagic freshwater habitats.
Recorded water conditions sit around 68–75 °F with a pH of roughly 6.0–7.5 — distinctly cooler than the warm tropical water associated with many aquarium loaches, and a reminder that not every stone loach comes from a warm lowland river. Strong current is a defining feature of the habitat, and any attempt to replicate it would need filtration turning over several times the tank volume per hour to approximate the flow and oxygenation of its home streams.
Feeding
Schistura yingjiangensis is presumed, on the strength of its family and habitat, to be a micro-predator foraging over the stream bed for small insect larvae, worms, crustaceans and zooplankton — the standard diet of small nemacheilid stone loaches in fast, clear water. FishBase records a trophic level around 2.7, consistent with this low-level invertebrate-feeding niche.
No aquarium feeding record exists for this species since it has never entered the hobby, but the family pattern points clearly to small live and frozen foods — bloodworm, brine shrimp, daphnia — over reliance on dried flake, should it ever be kept.
Mating
Nothing has been documented about courtship or spawning behaviour in Schistura yingjiangensis. The species has never been kept or bred in captivity, and no field observations of its reproductive behaviour appear in the available literature. This is honestly one of the many stone loaches known essentially only from its original description and a handful of confirmatory records.
Breeding
Breeding in Schistura yingjiangensis is unrecorded, both in the wild and in captivity — there is no documented spawning event for this species anywhere in the sources available. By analogy with other stone and brook loaches, it is presumed to be an egg-scatterer that releases eggs over gravel and stones in fast-flowing water, with no parental care, but this is an inference from the family rather than an observation of this species. Given it has never been exported for the aquarium trade, there is no realistic prospect of a captive spawning report to draw on.
In the aquarium
Schistura yingjiangensis has never been part of the aquarium hobby; it has no export history, no diagnostic husbandry notes and no care record beyond the field-level habitat data used to compile its profile. Any theoretical care approach would need to follow the stone-loach template drawn from its recorded conditions: cool water in the 68–75 °F range (markedly cooler than most popular aquarium loaches), a pH of roughly 6.0–7.5, and strong, well-oxygenated current maintained by heavy filtration — closer to a coldwater or subtropical hillstream setup than a typical tropical community tank.
As with other scaleless or fine-scaled loaches, caution around copper and full-strength medication would be a reasonable default. Because none of this has actually been tested in captivity, it should be read as an informed extrapolation rather than an established care sheet.
Conservation
Schistura yingjiangensis is assessed as Data Deficient (DD) on the IUCN Red List, an assessment dated 23 January 2010. As a range-restricted endemic known only from the Daying and Longchuanjiang Rivers in Yingjiang County, Yunnan, it warrants ongoing monitoring even though the IUCN has not been able to assign it a fuller status. It has no history in the aquarium trade, so any conservation pressure on the species would stem from habitat factors within its home rivers rather than collection for the hobby.