Taxonomy & naming
The species was formally described by Das and Darshan in 2017, in the journal Zootaxa (4337(3):403–412), under the name Physoschistura harkishorei. It was placed in the genus Mustura following Maurice Kottelat's broader 2018 taxonomic revision of the nemacheilid loaches, which reorganized several genera formerly grouped under Physoschistura and related lineages. As with much of Cobitoidea, this kind of generic reshuffling is common and ongoing, so older references and any future revisions may use a different combination for the same fish; the Catalog of Fishes remains the authority for the currently valid name.
Mustura harkishorei sits within Nemacheilidae, the stone or brook loach family — by far the largest family of loaches, with a huge number of species scattered across small, often single-stream ranges from South and Southeast Asia through the Himalaya into Central Asia and beyond. No information on the origin of the species epithet "harkishorei" was located in the sources consulted; it most likely honors a person named Harkishore, in the customary pattern of loach species named for collectors or colleagues, but this should not be stated as fact without the original etymology section of the description in hand.
Morphology
Mustura harkishorei is a small nemacheilid loach with the elongate, sub-cylindrical body typical of the family. The original description gives two useful field marks: the third and fourth pectoral-fin rays are produced, extending back to near the base of the pelvic fin, and the flank pattern carries thirteen black blotches alternating with smaller blotches above them along the body. The caudal fin has seventeen rays. Beyond these diagnostic details, no dedicated size or full colour-pattern account was found in the sources consulted, so exact maximum length and full adult coloration are not stated here rather than estimated.
Like other nemacheilids, this is a near-scaleless fish with the erectile suborbital spine typical of the wider Cobitoidea group, though the sources reviewed did not specifically describe the spine in this species. The near-naked skin shared across the family is worth noting for care purposes even where it is not explicitly confirmed here, since it is a defining trait of the group it belongs to.
Habitat
The species is known from the Dibang and Lohit Rivers in the Lower Dibang Valley district of Arunachal Pradesh, in far north-eastern India — both tributaries feeding into the greater Brahmaputra drainage. This places it in fast-flowing, clear hill-stream habitat typical of the eastern Himalayan foothills, the kind of cool, well-oxygenated water that stone and brook loaches are built for across their Eurasian range.
No published water-chemistry or temperature data for the type locality were found in the sources consulted. Given the setting — Himalayan foothill streams draining into the Brahmaputra — a cool-to-moderate, fast, clear, well-oxygenated stream is a reasonable general description of the habitat type, but specific figures are not asserted here without a documented source.
Feeding
No feeding studies or diet observations specific to Mustura harkishorei were located in the sources consulted. As a small benthic nemacheilid from fast, clear stream habitat, it almost certainly feeds as a micro-predator in the wild, picking small invertebrates, insect larvae and other invertebrate prey from the streambed — the pattern documented across the stone and brook loaches generally — but this profile does not extend that generalization into specific dietary claims for this particular species.
Mating
No information on courtship, spawning behaviour, or sexual dimorphism in Mustura harkishorei was found in the sources consulted. The species is not established in the aquarium hobby and appears to have no documented captive-breeding history, so nothing concrete can be said here beyond noting that data is sparse — which is itself the honest and typical situation for a narrowly distributed nemacheilid described only a few years ago.
Breeding
There is no record of Mustura harkishorei being bred in captivity. Based on the general pattern for stone and brook loaches (Nemacheilidae), the species is presumed to be an egg-scatterer that releases eggs over gravel or among stones in fast-flowing water, with no parental care — but this is an inference from the family's typical breeding mode, not a documented observation for this species specifically. No hobbyist or scientific report of a captive spawning was located, and the species is essentially unknown outside its native range, so breeding data here should be treated as sparse to nonexistent.
In the aquarium
Mustura harkishorei is not established in the aquarium trade. No care profile, husbandry account, or hobbyist reports were found in the sources consulted, and its recent description and narrow native range make it unlikely to be commercially available. As with other small nemacheilid stone loaches, any fish reaching hobbyists would be expected to need cool-to-moderate, clean, fast-flowing, highly oxygenated water and a stable, mature setup — but this profile does not manufacture aquarium-specific temperature, tank-size or tankmate recommendations that no source actually supports. Prospective keepers should treat this as effectively an unavailable, undocumented species rather than a known aquarium fish.
Conservation
Mustura harkishorei has not been evaluated by the IUCN Red List; no assessment exists. This is unsurprising for a species described in 2017 from a narrow range in the Dibang and Lohit Rivers of Arunachal Pradesh — many recently described, single-drainage nemacheilid loaches remain formally unassessed for years after description.
No information on population trend, specific threats, or conservation measures was located in the sources consulted. In general terms, small-range Himalayan foothill stream endemics of this kind can be vulnerable to habitat disturbance such as damming, siltation, and water-quality changes in their drainage, but no documented threat assessment for this particular species was found, so none is asserted here.