The Iberian Barbel is endemic to the Iberian Peninsula, Europe. It does not approach the range thresholds for Vulnerable under Criterion B1 (extent of occurrence (EOO) < 20,000 km²) or D2, and Criterion B2 is precluded by its uncertain area of occupancy (AOO). The population size is believed to exceed 10,000 individuals, therefore it does not approach the thresholds for Criteria C or D, and there exists no quantitative analysis which would permit application of Criterion E.

Although no range-wide population trend data exists, it is plausible that a suspected ongoing reduction based on a continuing decline in habitat quality may approach or meet the threshold for Vulnerable under Criterion A2; a decline of ≥ 30% over the past 21 years (three generations). As a result of this data uncertainty, Least Concern and Vulnerable are equally plausible Red List categories for the present assessment, therefore this species is assessed as Near Threatened (A2ce).

This species is native to rivers draining the Atlantic slope of the Iberian Peninsula, Europe. Its range extends southward from the Lima (es. Limia) River to the Sado River, and includes the large Douro (es. Duero) and Tagus (es. Tajo; pt. Tejo) river systems.

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. However, significant site-scale declines in abundance have been reported since the late 20^th century, especially in the Douro and Tagus river systems in Spain. It is suspected that this pattern is ongoing to an as yet undetermined extent, based on declining habitat quality (see 'Threats').

This species tends to be most abundant in the lower and middle reaches of medium-sized perennial river channels with clear water, moderate flow, well-developed riparian vegetation and rocky to stony substrata, e.g., mixed bedrock, gravel and pebbles. Adult individuals demonstrate a preference for deeper glides and pools, whereas juveniles occupy shallower marginal environments. It has has colonised some man-made reservoirs at locations where there is access to suitable upstream spawning habitat (but see 'Threats'). It also occurs in temporal rivers which are naturally dewatered during the summer and other periods of drought. The abundance of resident fishes is significantly reduced during these events, when some individuals survive in remnant pools or short perennial stretches.

The diet mainly comprises benthic macroinvertebrates, algae and organic detritus. The maximum recorded lifespan is 11 years. The majority of male individuals mature at age 3+, whereas females mature at 6–8+. It is a fractional spawner, and individual females are capable of releasing 3,000-25,000 eggs during a single reproductive season. The annual reproductive period is believed to extend from February to July, at which time adults migrate to specific upstream spawning sites with shallow, flowing water and coarse, stony substrata. During these movements they are able to pass smaller obstacles, including man-made structures, by leaping over them. Spawning itself takes place during May and June, and nuptial male individuals develop visible breeding tubercles on the head. Post-hatching, juveniles drift to nearby nursery sites and are often associated with submerged vegetation. They typically remain in upstream areas during their first summer.

At some locations in the Tagus River system it naturally hybridises with the congeneric Iberian Long-Snout Barbel (Luciobarbus comizo).

This species is threatened by river regulation and other forms of anthropogenic habitat degradation, which have resulted in widespread loss of the heterogeneous, interconnected fluvial habitats required to complete its life-cycle.

In particular, the construction of large dams plus smaller weirs and other barriers throughout its range has severely altered natural flow and sedimentation regimes, blocked migration routes, fragmented subpopulations, and reduced the extent of suitable habitat for all life stages. Hydroelectric schemes have created unnatural fluctuations in discharge and water temperature (hydropeaking and thermopeaking) which bring about artificial dewatering of downstream river stretches and 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 accumulation of fine sediments at some spawning sites, plausibly impairing the hatching and survival rates of eggs and larvae.

The quality of available habitat has been further diminished by bank stabilisation, channelisation and other efforts to enhance flood protection or exploit water resources for irrigated agriculture. Unregulated water abstraction may constitute a particular threat to this species' upstream spawning and nursery sites, some of which may also have been damaged by the industrial extraction of riverine gravel and other sediments for urban development.

It is also threatened by diffuse and point source agricultural, domestic and industrial pollution, which has at some locations reduced the extent and quality of habitat due to eutrophication or discharge of toxic substances. Pollution can be particularly impactful when discharge is reduced during the summer, especially in temporal rivers where native fishes are often confined to small refugia (see 'Habitat and Ecology').

Non-native aquatic species established within the Tagus Chub's range include Common Carp (Cyprinus domestic strain), Largemouth Bass (Micropterus salmoides), Pumpkinseed (Lepomis gibbosus), Northern Pike (Esox lucius), Eurasian Pikeperch (Sander lucioperca), Topmouth Gudgeon (Pseudorasbora parva), Eastern Mosquitofish (Gambusia holbrooki) and Red Swamp Crayfish (Procambarus clarkii), all of which are considered invasive and can exert detrimental pressures on native freshwater fauna through increased competition, predation, pathogen transmission or habitat degradation.

The negative impact of some threats could plausibly be exacerbated by increasingly rapid climate change in the Iberian Peninsula, which is already driving extended periods of drought.

This species is targeted by recreational fisheries, but is not otherwise used or traded.

This species is included in Appendix III of the Bern Convention (as Barbus bocagei) and Annex V of the European Union Habitat Directive (originally as Barbus spp.). It was assessed as Least Concern for the most recent (2023) iteration of the Portuguese Red Book of Freshwater and Diadromous Fishes, but is considered to be Vulnerable in Spain. It occurs within the boundaries of various protected areas, some of which are included in the European Union's Natura 2000 network.

It has been included in numerous studies investigating the efficiency of fishways in both Portugal and Spain, and some subpopulations may have benefitted from an increasing tendency to install or improve such structures on existing barriers within its range.

A deeper understanding of this species' demographics (population size and trend), current distribution, and life history, particularly the identification of key spawning sites, would likely prove useful in the development of future management efforts. Given the extent of its range, such efforts may be best coordinated at local or regional scales.