Loaches · Stone & brook loaches

Aborichthys rosammai

Sen, 2009

IUCNNOT EVALUATED
NEnot on the EX–LC scale
CARESNOT LISTED
Depthnot recorded
DietNo published dietary data; likely a bottom-foraging micro-predator of small invertebrates by analogy with related Nemacheilidae, but unconfirmed for this species
BreedingEgg-scatterer over gravel in fast water; no parental care; rarely or never bred in captivity — not documented for this species specifically, inferred from family biology
Sexual dimorphismMinimalNo published information on sexual dimorphism for this species
PhotographsSee photosGoogle Images →

Aborichthys rosammai is a little-known stone loach described in 2009 from a single Himalayan-foothill drainage in northeastern India, and it is a good example of how much of the Nemacheilidae — the largest loach family — remains poorly documented. It was found only in the Subansiri River system of Assam and Arunachal Pradesh, part of the Brahmaputra basin, and has not been recorded anywhere else. No size, temperature range, pH, diet or breeding data have been published for it, and it has never been assessed by the IUCN. It is not known to be in the aquarium trade, and this profile is written honestly around that scarcity rather than around guesswork.

What's in the name

Aborichthys rosammaiab-oh-RIK-thees roh-SAM-eye

Aborichthys
  • Aborregional namethe Abor (Adi) people of Arunachal Pradesh, whose hill country the genus was first described from
  • ichthysGreekfish — together 'fish of the Abor [hills]'
rosammai
  • rosammaieponymhonours Smti. Rosamma Mathew of the Zoological Survey of India

Taxonomy & naming

Aborichthys rosammai was described by Neelesh Sen in 2009, with its type locality given as Pabomukh on the Subansiri River, Dhemaji District, Assam, India (27°34'N, 94°14'E, at about 105 ft elevation). It was placed in Aborichthys, a small genus of stone loaches restricted to the eastern Himalayan foothills and the hill streams of northeastern India, and it belongs to the family Nemacheilidae, the true stone and brook loaches — by far the largest loach family, and one whose taxonomy has been reshuffled repeatedly as more species are described and re-examined.

In 2012 Maurice Kottelat reassigned the species to Schistura, the large genus that now holds the great majority of Himalayan and Southeast Asian stone loaches, and the Catalog of Fishes — the standing authority for valid names — currently lists the valid combination as Schistura rosammai (Sen, 2009). This profile follows the original combination, Aborichthys rosammai, as instructed; readers researching the species further should be aware that recent literature and databases will most often list it under Schistura. The species epithet honours Smti. Rosamma Mathew of the Zoological Survey of India.

Morphology

No detailed published description of size, coloration or meristic counts for this species has been located in the sources consulted here, so this section is deliberately brief rather than filled in from related species. As a member of Nemacheilidae it can be expected to share the family's general stone-loach build — an elongate, cylindrical body, a ventrally flattened head suited to a bottom-hugging life in current, and the small, near-scaleless skin typical of the group, which makes these fish sensitive to full-strength medications.

Members of Aborichthys and its relatives typically carry the small erectile suborbital spine found throughout the Cobitoidea, used defensively and as a identifying character within the family, though its exact form in this species has not been documented in the available sources. Precise size and colour pattern for Aborichthys rosammai are simply not published; anyone encountering wild or trade specimens should treat published measurements from congeners as approximate at best, not as data for this species.

Habitat

Aborichthys rosammai is known only from the Subansiri River system, a major tributary of the Brahmaputra draining the eastern Himalayan foothills of Arunachal Pradesh and Assam. Its type locality, Pabomukh, sits at a modest 105 ft elevation, placing the species in foothill rather than high-mountain stream habitat, though its full range within the Subansiri drainage has not been mapped in detail.

Streams of this kind in the eastern Himalayan foothills are typically cool to moderately warm, clear, fast-flowing and well-oxygenated, running over rock, gravel and sand — the standard hill-stream conditions that most Nemacheilidae are adapted to. No site-specific temperature, pH or flow data for this species have been published, so those characteristics are inferred from the general habitat type rather than measured; genuinely coldwater, high-elevation extremes reported for some Himalayan Schistura and Triplophysa should not be assumed to apply here without confirmation.

Feeding

No dietary study of Aborichthys rosammai has been published. Stone and brook loaches in fast, clear Himalayan streams are typically bottom-foraging micro-predators, picking small aquatic insect larvae, crustaceans and other invertebrates from among stones and gravel, and this species can reasonably be expected to feed the same way, but that is an inference from its family rather than a documented fact for this fish.

Because it has essentially no presence in the aquarium trade and no aquarium-feeding accounts exist, nothing further can honestly be said here. Anyone who does encounter this species should assume it needs the same small live and sinking foods that other stream-dwelling nemacheilids require, rather than flake.

Mating

Nothing has been published on courtship, spawning triggers, sexual dimorphism or reproductive behaviour in Aborichthys rosammai. Stone and brook loaches in this part of the world generally spawn by scattering eggs over gravel in flowing water with no pair bond and no parental investment, and that is the pattern most likely for this species, but it has not been observed or documented specifically.

Breeding

There is no published record of Aborichthys rosammai being bred, or even reliably kept, in captivity. Based on the breeding biology documented across Nemacheilidae generally, the expected mode is an egg-scatterer that releases eggs over gravel or among stones in fast-flowing water, with no parental care afterward — the same pattern seen in better-studied stone and brook loaches. This species should be assumed to fall into the same rarely-or-never-bred category as most of its relatives; there is no farm or hobbyist breeding program associated with it. This profile states that plainly rather than inventing a spawning account.

In the aquarium

Aborichthys rosammai does not appear to be an established aquarium fish — no size, temperature, pH, tankmate or husbandry information for it has been published, and it is not documented as being collected for the trade. Given that, any aquarium recommendation here would be fabrication, not information.

What can be said with confidence, by analogy with its Nemacheilidae relatives, is that a stone loach from a fast, cool, well-oxygenated Himalayan foothill stream would need strong water movement, high dissolved oxygen and a hard, stable substrate of rock and gravel rather than a warm, still community tank, and that its near-scaleless skin — typical of the family — would call for caution with copper and full-strength medications. Those points are offered as general stone-loach husbandry principles, not as verified requirements for this specific, essentially undocumented species.

Conservation

Aborichthys rosammai has not been evaluated by the IUCN Red List, so it carries no conservation category here — it is recorded as Not Evaluated rather than assigned a guessed status. As a species known only from a single river system (the Subansiri, part of the Brahmaputra basin) in Arunachal Pradesh and Assam, it fits the broader pattern of many recently described Himalayan-foothill stream endemics: narrow known range, no population data, and no formal assessment.

No information on collection pressure, habitat threats specific to this species, or trade activity has been located. The Subansiri basin, like much of the eastern Himalayan foothills, is subject to general regional pressures — hydropower development, deforestation and water-quality change — that affect stream fish communities broadly, but no source directly ties those pressures to this species' status. Given the near-total absence of published data, the honest position is that its conservation status is simply unknown.

Sources

  1. Eschmeyer's Catalog of Fishes (CAS) — Aborichthys rosammai Sen, 2009
  2. FishBase — Aborichthys rosammai (species ID 65802)
  3. IUCN Red List

Last reviewed 2026-07-01.

How to cite

Aquarist Atlas (2026). Aborichthys rosammai. Aquarist Atlas.https://www.aquaristatlas.com/loaches/aborichthys-rosammai/

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