Taxonomy & naming
The species was described by the Indian ichthyologist Sunder Lal Hora in 1935, hence the parenthetical authority. It was originally placed in Noemacheilus, one of the old catch-all genera used for Asian stone loaches through much of the twentieth century, and older literature and some databases still list it as Noemacheilus devdevi or Nemacheilus devdevi. Subsequent revision of the Nemacheilidae split those broad genera apart, and the Catalog of Fishes — the authority for valid names — now places the species in Schistura, the largest genus of stone loaches, with dozens of species distributed across South and Southeast Asia.
Schistura devdevi belongs to the family Nemacheilidae, the stone or brook loaches, by far the largest family within the loach superfamily Cobitoidea. Many Schistura species are known only from one or a handful of streams and are separated from close relatives by fine details of finnage, coloration and osteology, which is part of why generic boundaries in this group have shifted so often.
Morphology
This is a small, slender, cylindrical loach reaching only around 1.5 in (1.5 in) in standard length, among the smaller members of an already small-bodied genus. Like other nemacheilids it has a subterminal mouth adapted for grazing and picking food from the streambed, small barbels around the mouth, and — beneath each eye — an erectile suborbital spine, the defensive feature shared across the wider loach group.
The skin is effectively naked to the eye, covered only in tiny, deeply embedded scales, a trait that runs through the family and makes these fish sensitive to harsh treatments and rough handling. Precise details of its pattern and coloration are not well documented in the available literature; the common names "saddleback" and "firefly" loach hint at a marked body pattern, but a full description is beyond what the cache sources record, so we note that rather than guess at specifics.
Habitat
Schistura devdevi is native to upland streams of the eastern Himalayan foothills — the Indian states of Arunachal Pradesh, Assam, Sikkim and West Bengal, and adjoining Nepal. It lives in clear, swift-flowing streams with rocky or pebbly bottoms, the classic habitat of a stone loach: cool, well-oxygenated water tumbling over stone and gravel rather than the slow, warm, vegetated waters favoured by many other tropical aquarium fish.
This is a coldwater-leaning stream species, not a warm-tropical one. Reported temperatures run from about 59–72 °F, considerably cooler than the range most aquarium fish are kept at, and the water is typically hard and neutral to slightly alkaline. Any attempt to keep this species should replicate that current, oxygenation and cooler temperature rather than a standard warm, still community setup.
Feeding
Schistura devdevi is an omnivorous micro-predator, foraging over the stream bottom for small insects, worms and crustaceans, in keeping with the diet typical of stone loaches living in fast, clear water. It is not a specialist algae-grazer in the way some hillstream loaches are; its feeding is centred on picking small invertebrates from among the stones and gravel.
In the aquarium, fish of this type generally do well on small live and frozen foods — Daphnia, brine shrimp and bloodworm — offered so they sink to the bottom where the fish forages, and this species is not expected to thrive on dried flake alone. As with most small benthic stream loaches, feeding should be frequent and aimed at the substrate rather than the water column.
Mating
Nothing specific to Schistura devdevi has been documented about courtship, spawning triggers or sexual dimorphism in the available sources. Stone and brook loaches in the genus Schistura are, as a rule, poorly studied in this respect — most are small, cryptic stream fish that have never been observed spawning in the aquarium, and field data on their reproductive behaviour is sparse across the genus.
What can be said with confidence, by analogy with the wider Nemacheilidae, is that this is very unlikely to be a fish with elaborate courtship or parental behaviour. Stone loaches are egg-scatterers, not mouthbrooders or cave-guarding species, and any spawning would be expected to follow that pattern rather than anything more complex.
Breeding
As with the great majority of Nemacheilidae, Schistura devdevi is not known to have been bred in the home aquarium, and the available sources record no data on its reproduction in captivity. The expected pattern, based on the family as a whole, is an egg-scatterer that releases eggs over gravel or among stones in fast-flowing water, with no parental care given to eggs or fry afterwards.
Given how rarely this species even reaches the aquarium trade, verified spawning accounts are essentially nonexistent. A keeper should treat this as a data-sparse, unbred species rather than expect any established protocol, and should not assume any of the cave-guarding or mouthbrooding strategies seen in other fish groups — those do not apply to loaches.
In the aquarium
Schistura devdevi is rarely available in the trade, and keeping it well means recreating a cool, fast-flowing, highly oxygenated stream rather than a typical warm community tank. Strong water circulation and high dissolved oxygen are essential, alongside a rocky or gravel substrate that mirrors its native pebbly streambed. Regular, substantial water changes — on the order of 30–50% weekly — help maintain the clean, well-oxygenated conditions this species needs.
Being near-scaleless, like other loaches it is sensitive to copper-based medications and full-strength treatments, so any dosing should be conservative. It is described as a peaceful fish and an exceptional jumper, so a tightly fitted lid is necessary. At barely 1.5 in, it is a small fish suited to a modest but well-oxygenated setup rather than a large tank, though as with many small stream loaches it likely does best in a group rather than alone — a reasonable precaution even though specific shoaling data for this species is not documented.
Conservation
Schistura devdevi is assessed by the IUCN Red List as Near Threatened, an assessment dated 23 January 2010. Near Threatened status for a narrow-range upland stream species typically reflects a combination of restricted distribution and pressure on its habitat, though the cache sources available here do not detail the specific threats cited in the assessment.
The species is rarely seen in the aquarium trade, so hobby collection is not a significant pressure on it; its conservation concerns, to the extent documented, are tied to the condition of the clear, swift Himalayan foothill streams it depends on across its range in northeastern India and Nepal.