Taxonomy & naming
Oxynoemacheilus seyhanicola was formally described in 2007 by the Turkish ichthyologists Fahrettin Erk'Akan and Ahmet Nalbant together with Cüneyt Özeren, part of a wave of Anatolian nemacheilid descriptions in the 2000s that carved a diverse suite of local stream loaches out of the old, broadly-applied genus Noemacheilus (and later Nemacheilus). Oxynoemacheilus is a western Palaearctic genus, its species scattered through the river systems of Turkey, the Levant, the Caucasus and parts of the Middle East, with several — like this one — endemic to a single drainage.
The species epithet seyhanicola points directly to its type locality, the Seyhan River basin of Adana Province. It sits within the family Nemacheilidae, the stone or brook loaches, by far the largest family in the true-loach superfamily Cobitoidea and one still being actively revised as researchers work through the region's many short-range endemics. A closely related congener, Oxynoemacheilus sarus, was later described from the neighbouring lower Ceyhan and Seyhan system, underlining how finely subdivided this part of Anatolia's loach fauna has turned out to be.
Morphology
Like other Oxynoemacheilus, this is a small, elongate, cylindrical loach built for holding position on the bed of a running stream rather than for open swimming. Reported total length tops out at around 3.5 in, and specimens documented from a Seyhan tributary measured only 1.5–2 in standard length, suggesting most individuals in the wild are considerably smaller than the maximum. As in its relatives, the skin carries only fine, deeply embedded scales rather than a robust scale covering, and — as in the wider stone-loach group — an erectile spine below the eye is a family hallmark, though detailed anatomical description for this particular species is not available from the sources at hand.
Beyond size and family-typical build, published morphological detail specific to O. seyhanicola is sparse; the original description and subsequent taxonomic papers focus on the meristic and morphometric characters used to separate it from close congeners rather than on traits useful for a keeper. Honest reporting here means saying plainly that fine-grained morphological description of this species has not filtered down past the specialist taxonomic literature.
Habitat
Oxynoemacheilus seyhanicola is endemic to the lower Seyhan River, restricted to a stretch of only around 37 mi near Adana in southern Anatolia, Turkey — part of the Seyhan Basin that drains from the Taurus Mountains to the Mediterranean coast. FishBase describes it as a freshwater, demersal, subtropical species found over gravel substrate in moderately fast currents, the classic stone-loach habitat: a clear, flowing, oxygen-rich river reach rather than a still or sluggish one.
This is a narrow-range river specialist, not a lake or wetland fish, and its entire known distribution sits within a single, human-altered lowland reach of one river system. That narrowness is central to its conservation status: there is no broader metapopulation elsewhere to buffer against local habitat change.
Feeding
FishBase lists a trophic level around 2.8 for this species, consistent with a diet leaning toward algae, biofilm, detritus and small invertebrates picked from the gravel and stone surfaces of its river bed — a grazing and micro-predatory habit typical of small nemacheilid loaches in fast water, rather than a diet of larger prey. No aquarium-specific feeding observations exist for this species, since it is not established in the hobby.
By analogy with well-studied stone and brook loaches, a diet in this style would be met in captivity with small sinking foods — fine pellets, frozen bloodworm or daphnia, and some algae-based food — but this is inference from the genus and family rather than a documented account of the species itself.
Mating
No courtship or spawning behaviour has been documented for Oxynoemacheilus seyhanicola in the sources available. Sexual dimorphism has not been described for this species either. Stone and brook loaches in general show little external difference between the sexes outside the breeding season, with ripe females sometimes appearing rounder-bodied, but nothing specific to this species can be reported without guessing.
Breeding
As with the great majority of Nemacheilidae, Oxynoemacheilus seyhanicola is best understood as an egg-scatterer: eggs are expected to be released over gravel or among stones in fast-flowing water, with no parental care afterward, following the pattern typical of stone and brook loaches generally. There is no record of this species being bred in the aquarium, and given how narrowly it is known even in the wild, that is unsurprising — it is not a fish that reaches the trade or the hobby literature.
Data on this species' reproduction is genuinely sparse. Rather than invent detail, the honest summary is: egg-scattering over gravel with no parental care is the expected mode by family pattern, but the species has not been bred or observed spawning in captivity, and field observations of its natural spawning are not documented in the available sources.
In the aquarium
Oxynoemacheilus seyhanicola is not an aquarium fish in any practical sense — it does not appear in the ornamental trade, and there are no keeper accounts, care sheets or captive photographs to draw on. Anything said about tank care would be extrapolation from the wider stone-loach group rather than documented experience with this species, and that gap should be stated plainly rather than papered over.
What can be said with confidence, by analogy with its Nemacheilidae relatives, is that a fish from a moderately fast, gravel-bottomed, well-oxygenated stream reach would need strong flow, high dissolved oxygen and a gravel or stone substrate to do well, and — like other near-scaleless true loaches — would likely be sensitive to copper-based medications and full-strength treatments. But since this species is not kept, none of that has actually been tested, and it should not be represented as an aquarium fish.
Conservation
Oxynoemacheilus seyhanicola is assessed by the IUCN Red List as Endangered (EN), an assessment dated 15 January 2013 under criteria B1ab(i,ii,iii,iv)+2ab(i,ii,iii,iv) — criteria tied directly to its tiny, fragmented range and ongoing decline in extent, area and habitat quality. Its entire known distribution is roughly 37 mi of the lower Seyhan River near Adana, and the assessment cites dam construction, water extraction and climate change as the pressures acting on that single stretch of river.
Because the species is confined to one heavily used lowland river system in a rapidly developing part of Turkey, any further damming, abstraction or pollution along that reach has an outsized effect on the whole known population. It is not part of the aquarium trade, so collection pressure is not a factor here — the threats are entirely about what happens to the Seyhan River itself.