Taxonomy & naming
Schistura singhi was described by the Indian ichthyologist A. G. K. Menon in 1987. It belongs to the family Nemacheilidae, the stone or brook loaches — by far the largest family of loaches, with many hundreds of species spread across Eurasia, and one where taxonomic revision has been constant: the old genus Noemacheilus was long used as a catch-all before being split repeatedly into Nemacheilus, Schistura, Barbatula, Triplophysa and others. The species is named in honour of Dr. Kalika Prasad Singh, an ecologist at Banaras Hindu University.
As with many Nemacheilidae described from a single small stream, S. singhi has attracted little subsequent taxonomic attention; the original 1987 description by Menon remains the primary reference point for the species, and it is treated here under the currently accepted combination Schistura singhi.
This fish was long listed as Nemacheilus singhi; Eschmeyer's Catalog of Fishes places the species in Schistura, and the current combination Schistura singhi is followed here.
Morphology
This is a small loach, reaching only about 1.4 in in standard length — among the tinier members of a family that runs the gamut from minute to moderately large. Like other Nemacheilidae it has an elongate, only lightly compressed body, a small subterminal mouth suited to picking food off stones, and the near-scaleless or fine-scaled skin typical of the group, which makes these fish generally sensitive to medication. Detailed morphological description beyond the type material is limited; no dedicated aquarium-photography or hobbyist account of this species is available to add colour-pattern or fin-ray detail here.
Habitat
Schistura singhi is known from a single locality: a small stream with a pebbly bottom in the Kiphire district of Nagaland, in the northeastern Indian hill country. This is classic stone-loach habitat — a clear, flowing hill stream running over a coarse, stony substrate rather than sand or silt, the kind of fast, well-oxygenated water this family is built for.
No published data give the stream's actual temperature, pH or hardness for this species specifically. Comparable Nemacheilus species from similar South and Southeast Asian hill streams are generally documented around 72–77 °F with slightly acidic to neutral, moderately hard water, and that range is a reasonable proxy here — but it should be read as an informed estimate from related species, not a measurement of S. singhi's own stream.
Feeding
No dedicated dietary study of Schistura singhi has been published. Based on its build and the near-universal habit of Nemacheilidae in fast, clear streams, it is almost certainly a benthic micro-predator, picking small invertebrates — aquatic insect larvae, worms and tiny crustaceans — off stones and gravel. This is inferred from the family's general biology rather than confirmed for this species; there is no direct evidence to say more.
Mating
Nothing has been published on courtship or spawning behaviour in Schistura singhi. No dimorphism, breeding season, or reproductive biology has been documented for this species — it has simply not been studied beyond the original taxonomic description. For a stone loach of a fast hill stream, breeding activity would be expected to follow the general Nemacheilidae pattern of scattering eggs into flowing water without pairing rituals, but this is inference from family biology, not observation of this fish.
Breeding
There is no record of Schistura singhi being bred in the aquarium, and given its status as a single-locality, poorly known wild fish, this is unsurprising — it is not established in the hobby at all. Stone and brook loaches as a family are typically egg-scatterers, releasing eggs over gravel and stones in fast water with no parental care, and are rarely bred in captivity even when they do appear in the trade. Data for this specific species is sparse to the point of absence, so the honest statement is simply that its breeding is undocumented.
In the aquarium
Schistura singhi is not a fish encountered in the aquarium trade — it has no established hobby presence, and this profile exists to document the species rather than to recommend keeping it. Should material ever reach hobbyists, the general rules for small Nemacheilidae stone loaches would apply: cool-to-mild, clear, fast-flowing, well-oxygenated water over a stony or gravel substrate, a diet of small live or frozen invertebrate foods, and caution with medications given the family's thin, near-scaleless skin. Given the species' single-locality Vulnerable status, any wild collection would carry real conservation weight.
Conservation
Schistura singhi is assessed as Vulnerable (VU) on the IUCN Red List, under criteria B1ab(iii);D2, with the assessment dated 23 January 2010. This reflects its known occurrence at a single locality — a small stream in Kiphire district, Nagaland — which makes the entire species vulnerable to any degradation of that one stream, whether from siltation, pollution, deforestation or water abstraction in its catchment.
There is no indication that the aquarium trade plays any role in pressure on this species; the threats implied by its IUCN criteria are habitat-based and tied to the vulnerability of relying on a single known population. No broader distribution or population trend data has been published since the original assessment.