Taxonomy & naming
Schistura nagodiensis was described in 2006 by Sreekantha, Gururaja, Rema Devi, Indra and Ramachandra, part of a pair of new Schistura species the team described from the Western Ghats of India that year. It belongs to the family Nemacheilidae, the stone or brook loaches — by far the largest loach family, comprising hundreds of species of small, slender, benthic fishes spread across Eurasia. The genus Schistura is itself enormous, with well over 200 recognized species, most of them narrow-range endemics of fast hill and mountain streams from India east through Southeast Asia and southern China.
The species epithet nagodiensis refers directly to its type locality: Nagodihole, a stream ('hole' being the Kannada word for a small stream or rivulet) that feeds into the Sharavathi River. Older regional literature on Indian hill-stream fishes sometimes used the broader genus names Nemacheilus or Noemacheilus for similar-looking loaches, but no synonymy under those names has turned up for this species — it was described directly into Schistura, and the Catalog of Fishes governs the genus placement used here.
Morphology
This is a true stone loach in the classic Nemacheilidae mould: an elongated, cylindrical, scaleless-looking body built for holding position against current on a stream bed. FishBase records a maximum size of just 1 in standard length, making it one of the smallest loaches recorded from the Western Ghats — a genuine micro-species rather than a scaled-down version of the aquarium-trade botiids. The dorsal fin carries two spines and eight soft rays, the anal fin two spines and five rays, a fin-ray count consistent with the genus.
Like other members of Schistura, it is presumed to carry the erectile suborbital spine typical of the loach superfamily Cobitoidea, a small defensive spine tucked in a groove below the eye, though this has not been specifically documented for the species in the sources available. Its skin, like that of stone loaches generally, is functionally naked — the scales are minute and deeply embedded — which is a point of real practical relevance for any fish of this genus, though as this species has no keeping record, it is noted here for context rather than direct observation.
Habitat
Schistura nagodiensis is endemic to the Sharavathi River basin in the central Western Ghats of Karnataka, India, and is known specifically from its type locality, Nagodihole, a tributary stream at 1969–2625 ft elevation. FishBase describes the habitat as torrential hill streams with vegetation — fast, turbulent water running through a forested montane catchment, the classic setting for a Western Ghats hillstream endemic.
Detailed water chemistry and temperature data for this exact population were not available in the sources consulted; a paper on Sharavathi stream ecology that would likely have carried it could not be accessed. What can be said with confidence, based on the elevation and stream type, is that this is a coolwater, fast-flow, well-oxygenated habitat, not a warm, still one — Western Ghats montane streams at this elevation typically run cool and clear. We note this as an inference from habitat type rather than a measured range, and do not assign specific temperature figures we cannot source.
Feeding
No diet study has been published for Schistura nagodiensis specifically. Based on the genus, however, it can be described with reasonable confidence as a benthic micro-predator: Schistura species characteristically forage along the stream bed picking up small aquatic invertebrates, insect larvae and other tiny prey items dislodged by the current, a foraging style shared across the stone-loach family.
This is inference from the genus rather than a documented record for this exact species, and we flag it as such. There is no aquarium feeding record to draw on, since the species has no history in the hobby.
Mating
No courtship or spawning behaviour has been recorded for Schistura nagodiensis. Nothing in the sources available — the original description, FishBase, or the IUCN assessment — documents reproductive behaviour, seasonality, or sexual dimorphism for this species, and none should be invented. What can be said is that the genus Schistura, like Nemacheilidae generally, is not known for any elaborate courtship or pairing behaviour; these are stream fish that are presumed to spawn opportunistically in fast water rather than form pair bonds.
Breeding
As with the great majority of Nemacheilidae, Schistura nagodiensis is best assumed to be an egg-scatterer: releasing eggs over gravel or among stones in fast-flowing water with no parental care afterward, the pattern typical of stone and brook loaches across the family. This is not documented for the species itself, but it is the consistent pattern across the genus and the family, and there is no basis to expect a different mode such as cave-guarding or mouthbrooding, which belong to entirely different fish groups.
This species has never been bred in captivity — it is not in the aquarium trade at all — and given how little is known even about its basic ecology, any detail beyond the general family pattern would be speculation. Data on this axis is genuinely sparse, and that sparsity is itself informative: this is a scientifically described but essentially unstudied stream endemic.
In the aquarium
Schistura nagodiensis has no aquarium-keeping history. It is not collected or traded, it does not appear in hobbyist literature, and no husbandry recommendations exist for it specifically. Anyone extrapolating from the genus should assume it would need what stone loaches from fast Western Ghats hill streams generally require: cool, clean, heavily oxygenated, fast-moving water over a gravel or stone substrate, since this is what its native torrential-stream habitat provides — not the warm, still conditions suited to many lowland aquarium fish.
Because it is essentially unknown in captivity, any care advice beyond that general habitat inference would be guesswork, and none is offered here. Its value to an atlas like this one is as a record of a real, described, single-river endemic rather than as a species anyone is likely to keep.
Conservation
Schistura nagodiensis is listed as Endangered (EN) on the IUCN Red List, assessed in 2010 under criteria B1ab(iii)+2ab(iii) — criteria tied to a small, fragmented geographic range experiencing continuing decline in habitat quality. This status reflects its extremely restricted distribution: the species is known only from the Sharavathi River basin, and specifically from its type locality at Nagodihole, in the central Western Ghats.
The Western Ghats is a globally recognized biodiversity hotspot under severe and ongoing pressure from deforestation, hydroelectric development, agricultural conversion and stream habitat degradation, and a single-river endemic of this kind is intrinsically vulnerable to any one of those pressures affecting its catchment. The species has no role in the aquarium trade, so collection is not a relevant threat here; the risk is entirely about the fate of its home stream system.