Taxonomy & naming
Oxynoemacheilus hanae was formally described in 2017 by Jörg Freyhof and Rasoul Abdullah, based on a holotype male of 2 in standard length and a series of paratypes ranging from 1.5–2.5 in SL, all collected on 7 June 2012. It belongs to the family Nemacheilidae, the stone or brook loaches, which over the past two decades has absorbed most of what used to be lumped under the old catch-all genera Nemacheilus and Noemacheilus — those names have since been split across dozens of narrower genera, including Oxynoemacheilus, Schistura, Triplophysa and Barbatula, following the Catalog of Fishes as the governing authority for valid names.
The species epithet honours Hana Ahmad Raza, a biologist and conservationist with the Iraqi conservation group Nature Iraq, recognising her contribution to documenting the freshwater fauna of Iraqi Kurdistan. As a fish described only in 2017 from a single stream system, O. hanae has not yet accumulated a body of secondary literature; the original description remains essentially the only source of hard data on the species.
Morphology
Oxynoemacheilus hanae is a small loach, with the type series spanning 1.5–2.5 in standard length and the holotype measuring 2 in SL — modest even by the standards of the stone-and-brook-loach group, most of which stay under 4–6 in. The original description distinguishes it from its relatives by a combination of features: elongated blotches along the midline of the flank, dark-brown patches on the lower body, a deeply emarginate (forked) caudal fin, and — in males — a suborbital groove, the modified pit beneath the eye that in many nemacheilids houses a small erectile spine used in the family's characteristic below-the-eye defense structure.
Like other members of Nemacheilidae, O. hanae has the typical stone-loach build: an elongate, sub-cylindrical body, a flattened belly suited to hugging the streambed, and skin that is effectively naked or bears only minute embedded scales — a trait that makes this family, like most loaches, notably sensitive to medication and to handling.
Habitat
The type locality is the stream Zalm, south of Taparezina, in the upper Sirwan (Kurdish) drainage of Iraqi Kurdistan, at approximately 35°18'23"N 45°58'14"E — a headwater mountain stream. The original description characterises this as cool, fast-flowing, well-oxygenated water typical of upland stream habitat in the region, but no specific temperature or pH measurements were published alongside the species.
As with the great majority of Nemacheilidae, this puts O. hanae squarely in flowing, well-aerated freshwater rather than still or warm lowland water. The species is currently known only from this single drainage in Iraqi Kurdistan, part of the wider Tigris-Euphrates system that reaches west into the Middle East — the western edge of the loach family's broad Eurasian range, which otherwise stretches across South, Southeast and East Asia, the Himalaya and Tibetan plateau, and into Anatolia and Europe.
Feeding
No dietary study has been published for Oxynoemacheilus hanae specifically. Based on the well-established pattern across Nemacheilidae, it is presumed to be a micro-predator that forages over the streambed for small invertebrates — aquatic insect larvae and small crustaceans — picked from among gravel and stones in fast-flowing water, in keeping with its build and its cool, high-oxygen stream habitat.
No aquarium feeding data exists for this species. Given the family's general habits, a keeper would expect it to take small live and frozen foods and sinking preparations readily, and to show little interest in floating flake — but this is inference from its relatives, not an observation of the species itself.
Mating
There is no published account of courtship, spawning behaviour, or sexual dimorphism for Oxynoemacheilus hanae beyond the suborbital groove noted in males in the original description — a structural feature rather than a behavioural one. No aquarium or field observations of reproduction have been reported.
Breeding
Breeding biology for this species is unknown and unstudied. Based on the general pattern across the stone-and-brook-loach group, it is presumed to be an egg-scatterer that releases eggs over gravel or among stones in flowing water, with no parental care — but this is an inference from the family rather than a documented observation for O. hanae itself. Like the great majority of Nemacheilidae, it has never been reported bred in captivity, and given its very recent description and narrow, single-drainage distribution, it is unlikely to have entered the aquarium trade at all.
In the aquarium
Oxynoemacheilus hanae has no known aquarium history: no care reports, no trade records, and no evidence it has ever been kept in captivity. Nothing here should be read as tested advice. Were it ever available, the safe assumption drawn from its relatives and its cool, fast headwater-stream habitat would be a well-oxygenated, flowing setup with a gravel or stone substrate rather than a warm, still community tank — and, as with most loaches, care with medication given the near-scaleless skin typical of the family.
Given the total absence of trade or husbandry data, the honest statement is that this is a scientifically described but functionally unknown fish outside its home stream.
Conservation
Oxynoemacheilus hanae has not been assessed on the IUCN Red List and carries no conservation category; it is recorded here as Not Evaluated rather than assigned a guessed status. It is known only from a single stream in the upper Sirwan drainage of Iraqi Kurdistan, a pattern common among recently described nemacheilid loaches, many of which turn out to be narrow-range stream endemics.
With no population data, no known threats documented, and no assessment on record, its conservation status genuinely cannot be stated beyond Not Evaluated. There is no evidence of any aquarium trade in this species, wild-collected or otherwise.