Taxonomy & naming
Aborichthys waikhomi was described by Kosygin in 2012 in the Records of the Zoological Survey of India (Vol. 112, Part 1: 49–55), based on paratype specimens measuring 2.5 in standard length collected from the Bulbulia stream, a tributary of the Noa-Dihing river in Namdapha, Arunachal Pradesh, India. The species epithet honours a collector or colleague named Waikhom, in the standard pattern of Indian ichthyological eponyms from this region.
The genus Aborichthys sits in the family Nemacheilidae, the stone and brook loaches — by far the largest loach family, and one that has been repeatedly reshuffled as regional faunas are revised. Aborichthys is a small genus confined to the eastern Himalaya and adjacent hill drainages of northeastern India, with described relatives including A. elongatus, A. kempi and, more recently, A. uniobarensis, also from Arunachal Pradesh. As with many recently described Nemacheilidae from this region, the genus placement is treated here exactly as published; the Catalog of Fishes governs any future revision.
Morphology
Aborichthys waikhomi is a slender, elongate stone loach in the 2.5–3 in standard-length range, matching the paratype series of 2.5 in SL. The body carries 12–16 oblique black bands, and the caudal fin is truncate (square-cut rather than forked) and marked with irregular black blotches — a pattern that, along with band count and body proportions, is part of what separates it from its closest congeners.
As in other Nemacheilidae, the skin is effectively naked — the scales are minute and deeply embedded rather than forming an obvious covering — which makes the family sensitive to poor water quality and to medication, a point that matters as much for this species as for any other stone loach even though it has never been kept in aquaria. Detailed anatomical description beyond the original paratype measurements is not available from the sources consulted here; this is a genuinely data-sparse species.
Habitat
The type locality is the Bulbulia stream near Bulbulia village, a tributary of the Noa-Dihing river within the Namdapha area of Arunachal Pradesh, in the far northeastern corner of India near the Myanmar border. This is eastern Himalayan foothill country: fast, clear, cool, well-oxygenated hill streams running over stone and gravel substrates, the classic habitat type for the genus Aborichthys and for stone loaches generally.
No dedicated ecological survey of this species' water chemistry or seasonal habitat use was found in the sources consulted, and — as is common for single-stream Nemacheilidae described from small collecting expeditions — its habitat requirements should be inferred cautiously from the genus and family rather than stated as established fact for this species specifically.
Feeding
No feeding data specific to Aborichthys waikhomi were found. Stone and brook loaches of this type are bottom-dwelling micro-predators, working over stone and gravel in fast water for small invertebrates — aquatic insect larvae, worms and small crustaceans — rather than grazing algae or taking large prey.
In the absence of species-specific data, the safest statement is the genus-level one: this is very likely a micro-predatory forager on the small invertebrate life of its home stream, in keeping with the feeding ecology documented for related Aborichthys and other Nemacheilidae.
Mating
No information on courtship, spawning triggers or sexual dimorphism in Aborichthys waikhomi was found in the sources consulted. This is unsurprising: the species is known essentially from its original type series, and detailed reproductive biology has not been published for it. Stone and brook loaches in general do not pair-bond or build nests; spawning, where documented for related species, follows the seasonal rise in flow typical of monsoon-fed hill streams.
Breeding
There is no record of Aborichthys waikhomi being bred in captivity, and no aquarium-trade history to draw on. Nemacheilidae as a family are egg-scatterers with no parental care, releasing eggs over gravel and among stones in fast-flowing water, and the great majority of species — this one very much included — are rarely or never bred at home; most are not even in the hobby to begin with. Data here is sparse to the point of absence beyond the family-level pattern.
In the aquarium
Aborichthys waikhomi does not appear to be established in the aquarium trade, and no husbandry reports were found. If it or a close relative were ever kept, the sensible starting point is the genus and family pattern: cool-to-mild, fast-flowing, well-oxygenated water over a stone or gravel substrate, strong water movement and high dissolved oxygen to mimic a Himalayan foothill stream, and a scaleless, medication-sensitive fish that should be dosed cautiously and never with copper-based treatments. Given the type locality's swift hill-stream character, a warm, still, blackwater-style setup would be the wrong environment entirely.
Until real husbandry data exists for this species, any care sheet would be speculative; the honest position is that this is a scientifically described, essentially unknown fish rather than an aquarium species.
Conservation
Aborichthys waikhomi has not been assessed on the IUCN Red List and is recorded here as Not Evaluated. It is known only from its type locality in the Bulbulia stream tributary of the Noa-Dihing river, within the Namdapha area of Arunachal Pradesh, India — a small-range hill stream typical of the many recently described, single-locality Nemacheilidae from northeastern India that have not yet been the subject of a conservation assessment.
As with other narrow-range stream endemics in this region, the general pressures on eastern Himalayan hill streams — deforestation, water diversion and development in catchment areas — are the plausible long-term concerns, though no species-specific population or threat data were found. There is no evidence this species is present in the aquarium trade, so trade pressure is not a documented concern for it.