Loaches · Stone & brook loaches

Paraschistura aredvii

Freyhof, Sayyadzadeh, Esmaeili & Geiger, 2015

Anahita Loach

IUCNNOT EVALUATED
NEnot on the EX–LC scale
CARESNOT LISTED
Scientific size2 in5.6 cm standard length
Depthnot recorded
DietPresumed benthic micro-predator, taking small aquatic invertebrates and insect larvae, following the pattern typical of Nemacheilidae; not directly documented for this species
BreedingEgg-scatterer over gravel/stones in flowing water; no parental care (inferred from family; not documented in captivity)
Sexual dimorphismMinimalNot documented; no sexual dimorphism has been recorded for this species
PhotographsSee photosGoogle Images →

Paraschistura aredvii is a small, little-known stone loach described in 2015 from the Zohreh River drainage of Iran, part of the wider Tigris basin. It belongs to Nemacheilidae, the largest loach family and the group that fills fast, clear, cool streams across Eurasia with small bottom-hugging micro-predators. Reaching barely 2.5 in, it is a micro-endemic known from a handful of localities rather than a fish anyone has kept or bred, and almost nothing beyond its original description and a photograph or two has been published on it since. Its species name honours Aredvi Sura Anahita, the Avestan divinity of the waters — a fitting name for a fish that lives and, as far as anyone knows, dies entirely within the rivers of its homeland.

What's in the name

Paraschistura aredviipa-rah-SHIS-tuh-rah ah-red-VEE-eye

Paraschistura
  • paraGreekbeside, near
  • Schisturagenus namea related nemacheilid genus — together 'near Schistura', for its close relationship to that genus
aredvii
  • Aredvi Sura AnahitaAvestanan Indo-Iranian cosmological figure venerated as the divinity of the Waters, associated with fertility, healing and wisdom

Taxonomy & naming

Paraschistura aredvii was formally described in 2015 by Jörg Freyhof, Hadi Sayyadzadeh, Hamid Reza Esmaeili and Matthias Geiger, published in Ichthyological Exploration of Freshwaters as part of a broader revision of the genus Paraschistura in Iran. That same review also described the closely related Paraschistura kermanensis, reflecting how much diversity within Iran's stone loaches has only been formally sorted out in the last decade or two.

The genus Paraschistura sits within Nemacheilidae, the stone or brook loach family — by far the largest loach family, spread from the Balkans and Anatolia across the Middle East, Central Asia and the Himalaya to East and Southeast Asia. Nemacheilid taxonomy has been repeatedly reshuffled as older catch-all genera such as Nemacheilus and Noemacheilus were split apart; Paraschistura is one of the genera that emerged from that process for the region spanning Iran, Iraq and neighbouring parts of the Middle East. The Catalog of Fishes is the governing authority for the valid name, and there is no indication in the available literature that Paraschistura aredvii has since been reassigned.

Morphology

Paraschistura aredvii is a small, slender, elongated loach reaching a maximum standard length of only about 2 in, making it one of the smaller members of an already modestly sized family. Like other stone loaches it has scales present along the back, no suborbital flap, and a pelvic-fin origin set behind the origin of the dorsal fin — details used to separate it from closely related Paraschistura and Schistura species in the region.

Beyond the formal diagnostic characters used to distinguish it from its relatives, published descriptions of its colour pattern and general appearance are sparse; the species is documented mainly through the original taxonomic description and a small number of photographs from the field, including one from the Tang-e Shiv River in the Tigris basin. As with most nemacheilids, it can be expected to carry the family's characteristic small erectile suborbital spine and near-scaleless-feeling skin, though this has not been specifically confirmed for this species in the literature reviewed here.

Habitat

The species is known from the Zohreh River drainage in Iran, with material also documented from the Tang-e Shiv River, part of the Tigris basin — placing it within the wider network of rivers draining the Zagros Mountains toward the Persian Gulf. FishBase classifies it as a demersal, freshwater, subtropical fish inhabiting rocky streams, consistent with the fast, clear, rocky-bedded watercourses typical of stone loach habitat across the region.

Specific water chemistry and temperature data for this species have not been published. Nemacheilid stone loaches as a family are generally fish of cool-to-warm, clear, fast-flowing, well-oxygenated streams running over rock and gravel, and there is no reason from the available record to expect Paraschistura aredvii to differ from that pattern. Given its Zagros foothill setting, moderate rather than tropical temperatures and strong current with high dissolved oxygen are the reasonable expectation, though this remains an inference rather than a documented fact.

Feeding

No dedicated dietary study of Paraschistura aredvii has been published. Stone loaches in Nemacheilidae are, as a rule, benthic micro-predators, working the stream bed for small aquatic invertebrates — insect larvae, small crustaceans and other invertebrate prey — rather than grazing algae or taking large amounts of plant matter, and this species is very likely to follow the same pattern.

In the near-total absence of aquarium or field feeding observations for this particular species, the honest statement is that its diet is inferred from its family and genus rather than directly documented. Anyone attempting to keep it would be well advised to offer small live or frozen invertebrate foods that sink to the bottom, on the assumption that it forages there as its relatives do.

Mating

Nothing specific has been published about courtship or spawning behaviour in Paraschistura aredvii. Data on reproduction in this species simply does not exist beyond what can be inferred from its family. Nemacheilid stone loaches typically pair or group-spawn over gravel and stones in flowing water with no sustained courtship display and no lasting pair bond, but this has not been observed or recorded for this particular species.

Breeding

As with most stone and brook loaches, Paraschistura aredvii has not been bred in the aquarium as far as the available literature records, and given how recently it was described and how narrow its known range is, that is unsurprising. The expected pattern for Nemacheilidae generally is egg-scattering over gravel or among stones in fast-flowing water, with no parental care of eggs or fry once spawning is complete.

There is no record of this species being kept, let alone spawned, in home aquaria. Data is genuinely sparse here, and the honest position is that its captive-breeding biology is unknown rather than merely unremarkable.

In the aquarium

Paraschistura aredvii is not an aquarium fish in any practical sense — it does not appear to be part of the ornamental trade, and there are no husbandry reports to draw on. Everything offered here is inference from its family and genus, not documented experience with the species itself.

Were it ever available, its small adult size of around 2 in and its rocky, flowing-stream habitat suggest it would want a modest but well-oxygenated tank with strong water movement, a rocky or gravel substrate, and cool-to-moderate rather than tropical temperatures, in keeping with general stone loach care. Like other nemacheilids it should be assumed to have thin, delicate skin sensitive to copper and full-strength medications, warranting the same caution used with better-known scaleless loaches. None of this is species-specific guidance, however — it is a placeholder built from family-level knowledge in the absence of any real record of the fish in captivity.

Conservation

Paraschistura aredvii has not been evaluated by the IUCN Red List and carries no conservation category. As a species described only in 2015 from a narrow drainage in southern Iran — the Zohreh River system and the Tigris-basin Tang-e Shiv River — it fits the profile of a genuinely data-sparse micro-endemic: known from very few localities, with no population trend data and no dedicated conservation assessment published.

Iran's freshwater fish fauna, including its stone loaches, faces pressure from water abstraction, damming and drought across the Zagros river systems, but there is no species-specific data connecting those pressures to Paraschistura aredvii. In the absence of an assessment, the most honest statement is that its conservation status is simply unknown.

Sources

  1. FishBase — Paraschistura aredvii Freyhof, Sayyadzadeh, Esmaeili & Geiger, 2015
  2. Ichthyological Exploration of Freshwaters — Paraschistura kermanensis, a new stone loach species from southeastern Iran (original review describing the genus in Iran, incl. P. aredvii)
  3. ResearchGate — Paraschistura aredvii, photograph from Tang-e Shiv River, Tigris basin
  4. Iran Endemic Freshwater Fish Checklist

Last reviewed 2026-07-01.

How to cite

Aquarist Atlas (2026). Paraschistura aredvii. Aquarist Atlas.https://www.aquaristatlas.com/loaches/paraschistura-aredvii/

Where it has been recorded

2 georeferenced records (GBIF). Each point is a field observation or museum specimen — pan and zoom to explore where this species turns up. The coordinates come straight from GBIF and are often rounded or tied to the nearest town or river landing, so a dot can sit just beside the actual water rather than in it.

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