The Channel Minnow (Phoxinus phoxinus), formerly Common or Eurasian Minnow, was for a considerable period of time treated as the only European member of the genus Phoxinus. However, at least 23 distinct mitochondrial lineages and 14 valid species have been identified in the region since the mid-2000s. This diversity is likely to increase further, as comprehensive information for all major European river systems has not yet been compiled. Moreover, additional sampling combined with morphological analyses are required to corroborate some putative species divisions (Denys et al. 2020, Palandačić et al. 2017, 2020, 2022, Bogutskaya et al. 2023).

Taxonomic determination has been further hampered by natural phenotypic variability within the different lineages, plus their disparate geographic distributions which do not generally reflect patterns observed in related European fish genera. Furthermore, anthropogenic translocations linked to recreational fisheries have in some cases led to uncertainty regarding native range boundaries and driven introgressive hybridisation between congeners (Museth et al. 2007, Knebelsberger et al. 2015, Miró and Ventura 2015, Ramler et al. 2017, Vucić et al. 2018, Corral-Lou et al. 2019, Palandačić et al. 2020, 2022, De Santis et al. 2021).

As a result of this increasing species diversity, much of the published literature referring to Phoxinus phoxinus in fact pertains to other taxa and should therefore be reviewed with due care.

Although this species' population trend may be decreasing due to habitat degradation, there is no evidence that the rate of decline approaches the minimum threshold for Vulnerable under Criterion A (≥ 30% over the longer of 10 years or three generations). It does not approach the range thresholds for Vulnerable under Criterion B (extent of occurrence (EOO) < 20,000 km², area of occupancy (AOO) < 2,000 km2) or D2. The population size is understood to exceed 10,000 mature individuals, hence it does not approach the thresholds for Criteria C or D. There exists no quantitative analysis which would permit application of Criterion E.

Therefore, the Pyrenean Minnow does not currently meet the thresholds for any Red List criteria, and it is assessed as Least Concern.

This species is native to rivers draining to the Bay of Biscay, where its range extends eastward from the Esva River in the Principality of Asturias, Spain, to the Eyre and Adour systems in southwestern France.

It is also present in the Ebro River in Spain's Mediterranean basin, from its headwaters in Cantabria downstream to the Gállego and Huerva tributary systems in Aragon. Recent research indicates that it does not occur in the lower Ebro catchment.

Elsewhere in Spain, introduced subpopulations are present throughout much of the northeastern Douro (es. Duero) River system and in the Da Chanca River, Galicia. In France, it has been introduced to the Aude River and some high-altitude lakes in the Pyrenees mountains.

This species' population size is unknown, but is understood to exceed the minimum threshold for Red List criteria (< 10,000 mature individuals). The current population trend has not been quantified, and the number of subpopulations is unclear.

In Spain it reportedly remains abundant where suitable habitat conditions exist.

This small-bodied, gregarious species occurs at a range of altitudes, but is most frequently-encountered in upland rivers, streams and oligotrophic lakes.

It demonstrates a preference for relatively shallow shorelines, pools and glides with well-oxygenated, clear water and slow to moderate water movement, but may move to deeper areas during cold periods.

It mostly feeds on aquatic invertebrates, supplemented by smaller quantities of organic detritus and plant material.

Adult individuals reach sexual maturity at age 1-2+. The annual reproductive period extends from April to June, but may commence several weeks later and continue until July or August at higher altitudes. This species is a fractional, polygamous spawner, and older individuals tend to spawn earlier in the season. Spawning behaviour is characterised by mature adults migrating short distances to specific sites, usually comprising beds of aquatic vegetation or well-washed gravel. Reproductive males develop a conspicuous epigamic colour pattern, and often aggregate in the vicinity of spawning sites prior to the arrival of females. Epidermal breeding tubercles appear on the head in both sexes, but are more prominent in males.

Construction of dams, sills, weirs and other barriers throughout this species' range has altered natural flow and sedimentation regimes, fragmented subpopulations and plausibly reduced the extent of suitable habitat for all life stages throughout much of this species' range. Habitat quality has been further diminished by the industrial extraction of gravel and other sediments for urban development, plus flood mitigation or water abstraction schemes such as bank stabilisation and channelisation.

It is further threatened by diffuse and point-source agricultural, domestic or industrial pollution at some locations. In the future, some effects of climate change such as increased water temperature or longer periods of low discharge during summer could exacerbate water quality issues, e.g., eutrophication.

The introduction of non-native congeners through their use as live bait in the recreational fishing sector may also comprise a threat due to the risk of introgressive hybridisation.

Some subpopulations may be threatened by the presence of predatory non-native fish species such as Rainbow Trout (Oncorhynchus mykiss). At some locations, restocking with hatchery-reared Brown Trout (Salmo trutta) may represent a threat due to the risk of over-predation, or the transmission of non-native diseases or parasites.

This species is sometimes utilised as live bait by recreational anglers. Captive-bred individuals of unknown provenance are also sold in the European pet trade for stocking in ornamental ponds.

This species is present within the boundaries of various protected areas, including two national parks and a series of sites included in the European Union's Natura 2000 network.

Some subpopulations may have benefitted from improvements in habitat and water quality associated with implementation of the European Union Water Framework Directive 2000/60/EC, such as efforts to restore fluvial connectivity through barrier removal or the creation of fishways.

A deeper understanding of its population trend, current distribution and life history, particularly the identification of key spawning sites, would likely prove useful should dedicated management efforts be deemed necessary in the future.