Taxonomy & naming
Oxynoemacheilus gyndes was described by Jörg Freyhof and Ali H. Abdullah in 2017, in a paper naming two new species of Oxynoemacheilus from the Tigris drainage in Iraqi Kurdistan (published in Zootaxa 4238(1)). The species epithet gyndes refers to the Gyndes, the ancient Greek name for the Sirwan River recorded by Herodotus — the type locality lies in the upper reaches of that drainage.
The genus Oxynoemacheilus is one of several groups carved out of the old, catch-all Nemacheilus/Noemacheilus over the past few decades, alongside Schistura, Triplophysa and Barbatula, as the family Nemacheilidae has been progressively split along regional and morphological lines. The Catalog of Fishes lists Oxynoemacheilus gyndes Freyhof & Abdullah, 2017 as the currently valid name, and it is treated here without alteration.
Morphology
This is a small, elongated loach reaching about 2 in standard length. It has 8-9 dorsal soft rays and 5 anal soft rays, a very short lateral line that extends only slightly behind the base of the pectoral fin, and a slightly emarginate (shallowly forked) caudal fin. The body is essentially scaleless apart from a small patch on the posteriormost part of the caudal peduncle — a trait shared across the true loaches and one with real consequences for how the fish should be handled and medicated.
Colour pattern consists of a midlateral series of small dark-brown blotches running along an otherwise pale to olive body, giving a broken, dashed-line appearance rather than a solid stripe or bold banding. Males of this species lack a suborbital groove, a detail used to help distinguish it from its close congeners in the original description. As with many recently described Oxynoemacheilus, no photographs or detailed behavioural notes beyond the type description are readily available, and much of its natural history remains undocumented.
Habitat
Oxynoemacheilus gyndes is known only from the upper Sirwan (Gyndes) drainage, part of the Tigris basin in Iraqi Kurdistan — a narrow endemic range in cool, clear, fast-flowing streams typical of the foothill and upland waters of this region. FishBase classifies its habitat as subtropical freshwater and demersal, meaning it lives and forages on or near the stream bottom rather than in open water.
As with most stone and brook loaches, this is emphatically not a warm, still-water fish: the Sirwan headwaters run cool and highly oxygenated over gravel and stone substrate, conditions this species and its relatives are adapted to rather than the soft, tannin-stained lowland rivers favoured by tropical loach groups such as the botiids.
Feeding
FishBase's estimated trophic level of 2.8 places Oxynoemacheilus gyndes as an omnivore leaning toward micro-predation, consistent with the feeding habits documented across Nemacheilidae: picking small invertebrates, insect larvae and other benthic prey items from among stones and gravel in fast-flowing water, supplemented by algae and detritus grazed off the substrate.
No aquarium feeding observations exist for this species specifically, since it is not established in the hobby. Based on its close relatives, a diet mirroring wild habits — small live and frozen foods such as bloodworm and brine shrimp, plus sinking foods that reach the bottom before larger tankmates intercept them — would suit a fish adapted to hunting along a stream floor rather than at the surface.
Mating
No courtship or spawning behaviour has been documented for Oxynoemacheilus gyndes. The species was described from preserved type material collected for taxonomic study, and no external sexual dimorphism beyond the male's lack of a suborbital groove (used as a diagnostic character against related species) has been reported. Data on this aspect of its biology is genuinely sparse rather than merely unpublicized.
Breeding
Breeding biology for Oxynoemacheilus gyndes has not been documented, and the species is not known to have been kept or bred in the aquarium hobby. Based on the pattern seen across stone and brook loaches generally, spawning in this group typically takes the form of scattering eggs over gravel or among stones in fast-flowing water, with no parental care of eggs or fry.
Given the narrow, recently discovered range of this species and its apparent absence from the aquarium trade, there is no record — anecdotal or scientific — of home or farm spawning. The honest statement is that its reproduction in captivity is unstudied.
In the aquarium
Oxynoemacheilus gyndes does not appear to be established in the aquarium hobby; it is very likely not in trade at all, and this profile is built from taxonomic and museum-collection sources rather than fishkeeping accounts. Were it to be kept, its close relatives among the stone and brook loaches point clearly to the requirements: cool-to-mild, clear, well-oxygenated, fast-flowing water over a gravel or stone substrate, with strong filtration turning over several times the tank volume per hour to replicate a stream current.
As a near-scaleless loach it would be expected to share the group's sensitivity to copper-based medications and full-strength treatments generally, meaning any future keeper should default to half-doses and gentle products. At barely 2.5 in it is a small fish, but given how little is known of its social needs, a cautious keeper should assume — as with most small benthic loaches — that it does better in a group than alone.
Conservation
Oxynoemacheilus gyndes has not been formally assessed on the IUCN Red List and is recorded here as Not Evaluated. Its very narrow known range — the upper Sirwan drainage of the Tigris basin in Iraqi Kurdistan — combined with its recent description in 2017, means population trends, threats and true extent of occurrence are essentially undocumented.
As with many recently described, narrow-range stream endemics in this part of the Middle East, water extraction, damming and habitat degradation in the wider Tigris basin are plausible long-term pressures, but no species-specific assessment exists to confirm or quantify them. This is a fish that would benefit from a formal IUCN evaluation given how restricted its documented distribution is.