The Channel Minnow (Phoxinus phoxinus), formerly the 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 plus morphological analyses are required to corroborate some putative species divisions which are currently supported only by inconclusive nuclear data (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 the 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.

Global and European regional assessment: Least Concern (LC)
EU 27 regional assessment: Least Concern (LC)

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 far exceeds 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 Channel Minnow does not currently meet the thresholds for any Red List criteria, and it is assessed as Least Concern both globally and for the EU 27 Member States.

This species is native to rivers of the North Sea and English Channel in Western Europe. Its continental range extends southward from the Rhine River system in Germany to Normandy in France, while it is present throughout Great Britain but might only be native to eastern and southern England, from the Humber Estuary to Cornwall.

The precise limits of its distribution in the upper Rhine catchment are unclear, but it appears to be absent from the Main River in Germany plus the High Rhine and Alpine Rhine (including the Aare River and associated lakes) in Switzerland. The congeneric Danube Minnow (Phoxinus csikii) is native to these areas, and there may be an extensive contact zone between the two species around the border of their ranges.

Introduced subpopulations are established in Ireland, the island of Corsica (France), Austria, and possibly elsewhere in Europe.

This species' population size is unknown, but significantly exceeds 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.

Field observations indicate that it remains abundant where favourable habitat conditions exist, although declines in abundance have been documented throughout parts of its range since at least the mid-20^th century, e.g., the Seine River, France.

This small-bodied, gregarious species is most frequently-encountered in the middle and upper reaches of rivers and streams, but also inhabits oligotrophic lakes and artificial reservoirs created by dams.

It is somewhat eurytopic, but demonstrates a preference for relatively shallow lake shorelines or fluvial pools and glides with well-oxygenated, clear water and slow to moderate water movement. At some locations it may move to deeper areas during periods of cold weather.

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

The maximum recorded age is 11 years, and 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. Hydroelectric schemes have created unnatural discharge and water temperature regimes (hydropeaking and thermopeaking), which bring about artificial dewatering of downstream river stretches and the loss of stable nursery habitat for juveniles. Furthermore, the combined effect of hydropeaking, dam flushing operations, changes in land use, and the removal of riparian vegetation has increased the accumulation of fine sediments at some spawning sites, thus impairing the hatching and survival rates of eggs and larvae.

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.

This species is also impacted 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.

Some subpopulations may be threatened by introgressive hybridisation with introduced congeners, e.g., Danube Minnow (Phoxinus csikii) and Languedoc Minnow (P. septimaniae) in the Meuse (Belgium and Netherlands) and Sieg (lower Rhine, Germany) rivers, or from predation by 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 or as feed in salmonid production facilities, but is not otherwise used or traded.

This species is present within the boundaries of various protected areas, including several national parks. In the EU 27 member states, some of these are included in the 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 native distribution in addition to its population trend and life history, e.g., the identification of key spawning sites, would likely prove useful should dedicated management efforts be deemed necessary in the future. Given the nature of its range, such efforts may be best coordinated at separate local or national scales.