Alburnus alburnus (Linnaeus, 1758)

Common Name: Bleak

Synonyms and Other Names:

alver, Abramis alburnus, Alborella maxima, Alburnus acutus, Alburnus charusini, Alburnus lucidus, Alburnis striatus, Aspius alburnoides, Cyprinus alburnus, Leuciscus alburnus

David Perez ( Info

Identification: Alburnus alburnus is a small fish with a slim and streamlined body. It is pale in color with silver sides and easily detached scales. This species has a protruding lower jaw and its mouth points upward. Fins are colorless to slightly gray or orange. Its caudal fin has 19 rays (Spillman, 1961). The anal fin has 17-20½ branched rays and its origin is below the branched dorsal rays 4-5 (Kottelat and Freyhof 2007). It possesses 16-22 gill rakers. The ventral keel is exposed from the anus to pelvic base. The lateral stripe is absent or faint.

Size: 9 – 15 cm total length (Billard 1997).

Native Range: East slope of Pyrenees towards Ural Mountains and Emba (Pérez-Bote et al. 2004; Kottelat 1997). North of the Pyrenees, Cacasus, and Alps.


Nonindigenous Occurrences: It is currently present in Cyprus through accidental introduction (Vinyoles et al. 2007). Its range extends throughout most of the Iberian Peninsula, including Italy, Portugal, Spain (Kottelat 1997). Between 2002 and 2003, bleak in the Catalonian basins was limited within the Llobregat, Ebre, Fluviá, and Muga basins; however, by 2008, it had increased its range to include the Ter and Foix basins (Maceda-Veiga et al. 2010).

Ecology: Alburnus alburnus inhabits slow flowing streams and temperate lakes in Europe and Asia (Kottelat 1997). It is a sterohaline fish that lives in brackish water with salinities of 8-10‰ (Linden et al. 1979). Cyprinidae fish such as Alburnus alburnus are strictly intolerant of sea water (Myers 1949). It typically inhabits waters with temperatures ranging from 10°-20°C (Baensch and Riehl 1991). In order for this species to reproduce, the minimum temperature requirements is 14°C (Souchon and Tissot 2012). It can acclimate to temperatures up to 37.7-40.6°C if temperatures are raised gradually (Horoszewics 1973).
Alburnus alburnus cannot tolerate low-oxygen waters (Willemsen 1980), but is highly tolerant to pollution (Linden et al. 1979). Pollutants such as brominated flame retardants were found to bioaccumulate in Alburnus alburnus that established as a nonnative fish in Spain (Eljarrat et al. 2005). The establishment of this species is facilitated by dams (Vinyoles et al. 2007). Alburnus alburnus co-occurs with other nonindigenous species in the Iberian Peninsula (Maceda-Veiga et al. 2010).
Alburnus alburnus feeds during the day on zooplankton and insects in the eplimnion (Vašek and Kubecka 2004; Keckeis and Schiemer 1990; Maceda-Veiga et al. 2010). It also feeds on terrestrial insects that fall into lakes and subsequently excretes terrestrial derived nutrients, thereby subsidizing lake nutrient pools (Mehner et al. 2005). This species may affect water quality by feeding on cladocerans and other small invertebrates that directly affect water quality (Maceda-Veiga et al. 2010). The prey of this species is geographically widespread, allowing it to establish successfully outside its native range (Vinyoles et al. 2007). In comparison to another common fish (Rutilus rutilus), Alburnus alburnus has a relatively limited diet (Keckeis and Schiemer 1990).
It has a high reproductive rate and is able to hybridize with other cyprinids (Vinyoles et al. 2007). The larvae of this species inhabits the littoral zone of rivers and lakes, while juveniles inhabit the pelagic zones (Kottelat 2012). It is able to hybridize with other cyprinid genera including Squalius, Blicca, Rutilus, and Abramis (Maceda-Veiga et al. 2010; Blachuta and Witkowski 1984, Crivelli and Dupont 1987).

Means of Introduction: Alburnus alburnus has a moderate probability of introduction to the Great Lakes (Confidence level: High).

Potential pathway(s) of introduction: Transoceanic shipping (ballast water).
From its native range, Alburnus alburnus was locally introduced to the Iberian Peninsula, Spain, Portugal, and Italy (Kottelat 1997). This fish species was intentionally introduced to the Northern Iberian watershed by anglers in attempt to increase the stock of forage for nonnative fish predators and was used as a popular live baitfish (Vinyoles et al. 2007). Alburnus alburnus is found in the Seine, Loire, and Rhine Rivers, which naturally discharge into the Atlantic Ocean (Leuven et al. 2009).

Through travel across the Atlantic Ocean from Europe, Alburnus alburnus may suffer mortality in ballast water due to its inability to survive waters with high salinity, limiting its introduction to the Great Lakes (Wheeler 1978). However, it has been shown that 35% of “No Ballast on Board” (NOBOB) vessels, which are exempt from mandatory ballast exchange, possess at least 1 tank with ≤ 5‰ salinity, thus enhancing the potential for Alburnus alburnus to survive transport overseas to be introduced into the Great Lakes (Niimi and Reid 2003).

Currently, the geographical distribution of Alburnus alburnus does not cover water bodies connected to the Great Lakes basin. Alburnus alburnus is not a popular aquarium fish and is not available for purchase online. Alburnus alburnus is not available as live baitfish for online purchase in North America. There are import restrictions regarding the transport of Alburnus alburnus to the United Kingdom (Clarke 2006). It is predicted that the geographical range of this species will expand due to climate change (Lehtonen 1996).


Status: Not established in North America, including the Great Lakes.

Alburnus alburnus has a high probability of establishment if introduced to the Great Lakes (Confidence level: High).

Following its introduction into the Ebro basin in Spain, this species rapidly established throughout the entire Iberian Peninsula, where it is currently present in all of the major Iberian water basins and a large number of Iberian rivers, suggesting that it has the ability to adapt to a warmer climate regime (Vinyoles et al 2007). After its establishment in Britain, Alburnus alburnus consequently spread and established in Cyprus. It is believed that the high fecundity rate of this species is responsible for its establishment.

If Alburnus alburnus were introduced to the Great Lakes, it has the potential to spread rapidly (Kolar and Lodge 2002). The climate of the Great Lakes is similar to the native range of Alburnus alburnus and this species is likely capable of enduring overwintering conditions in the Great Lakes basin (EPA 2008; Reid and Orlova 2002; Grigorovich et al. 2003). It is likely that the Great Lakes contain an abundant food source for this species. This species has a high reproductive rate (Vinyoles et al. 2007). It has not been reported that any natural enemy of Alburnus alburnus such as the tapeworm Ligula intestinalis, occurs in the Great Lakes region. In the Thames River, Ligula intestinalis preferentially parasitizes Alburnus alburnus, which impairs its swimming ability and increases the risk of predation (Harris and Wheeler 1974).

Great Lakes Impacts: Alburnus alburnus has the potential for high environmental impact if introduced to the Great Lakes.
Alburnus alburnus is a superior competitor because of its high reproductive rate, its non-specific diet, and its ability to tolerate a broad range of temperatures. Alburnus alburnus exhibits large and sudden bursts in population size so it has outcompeted native species where established (Perez-Bote et al. 20007; Vinyoles et al. 2007; Welcomme 1988). It is able to hybridize with other cyprinids (Maceda-Veiga et al. 2010; Blachuta and Witkowski 1984, Crivelli and Dupont 1987). Besides impacting native fish fauna, Alburnus alburnus feeds on cladoceran and other small invertebrates that play an important role in freshwater ecosystems and directly affect the water quality (Maceida-Veiga et al. 2010). This species exhibits a high level of plasticity in population traits and is able to adapt to a wide variety of environmental conditions. The mortality rate of Alburnus alburnus is higher in rivers than in lakes, but reproduction rates are higher in rivers (Almeida et al. 2014).

In the Iberian watershed, Alburnus alburnus threatens endemic species through hybridizing with other cyprinids and its generally high reproductive rate (Vinyoles et al. 2007).

There is little or no evidence to support that Alburnus alburnus has the potential for significant socio-economic impact if introduced to the Great Lakes.
Alburnus alburnus may affect water quality by feeding on organisms that play a direct role in water quality (Maceida-Veiga et al. 2010).

Alburnus alburnus has the potential for high beneficial effects if introduced to the Great Lakes.
This species may be commercially valuable as forage fish and baitfish (Pérez-Bote et al. 2007), and the artificial pearl trade (Denton and Nicol 1965). In Europe, it has been introduced into various reservoirs to benefit the populations of exotic fish predators such as the northern pike (Esox Lucius), largemouth bass (Micropterus salmoides), zander (Sander lucioperca), and wells catfish (Silurus glanis) (Maceda-Veiga et al. 2010). Establishment of Alburnus alburnus may increase productivity of predator fish in the Great Lakes, especially for predatory fish that do not have specific diets.

Management: Regulations (pertaining to the Great Lakes region)
There are no known regulations for this species.*

*Ballast water regulations applicable to this species are currently in place to prevent the introduction of nonindigenous species to the Great Lakes via shipping. See Title 33: Code of Federal Regulations, Part 151, Subparts C and D (33 CFR 151 C) for the most recent federal ballast water regulations applying to the Great Lakes and Hudson River.

Note: Check federal, state/provincial, and local regulations for the most up-to-date information.

There are no known biological control methods for this species.

There are no known physical control methods for this species.

There are no known chemical control methods specific to this species. General piscicides (such as rotenone) may be used for control, but expect significant kill of non-target species.

Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.


Almeida, D., Stefanoudis, P. V., Fletcher, D. H., Rangel, C., and da Silva, E. 2014. Population traits of invasive bleak Alburnus alburnus between different habitats in Iberian fresh waters. Limnologica 46: 70-76.

Baensch, H.A. and Riehl, R. 1991. Aquarien atlas. Bd. 3. Melle: Mergus, Velag für Natur- und Heimtierkunde, Germany. 1104 p.

Billard, R. 1997. Les poisons d’eau douce des riviéres de France. Identification, inventaire et repartition des 83 espéces. Lausanne, Delachaux & Niestlé (192 p.).

Blachuta, J. and Wikowski, A. 1984. Natural hybrids Alburnus alburnus (L.) X Rutlius rutilus (L.), Alburnus alburnus (L.) X Blicca bjoerkna (L.) and Alburnus alburnus (L.) X Abramis brama (L.) from the Oder river. Acta Hydrobiologica 25/26:189-203.

Clarke, M. 2006. Fish imports restricted. Published on Practical Fishkeeping News. Accessed 05 June 2014. Available

Crivelli, A.J. and Dupont, F. 1987. Biometrical and biological features of Alburnus alburnus x Rutilus rubilio natural hybrids from Lake Mikri Prespa, northern Greece. Journal of Fish Biology 31(6): 721-733.

Denton, E.J. and Nicol, J.A.C. 1965. Studies on reflexion of light from silvery surfaces of fishes, with special reference to the bleak, Alburnus alburnus. Journal of Marine Biological Association of the United Kingdom 45(3): 683-703.

Eljarrat, E., de la Cal, A., Raldua, D., Duran, C., and Barcelo, D. 2005. Brominated flame retardants in Alburnus alburnus from Cinca River Basin (Spain). Environmental Pollution 133(3): 501-508.

Environmental Protection Agency (EPA). 2008. Predicting future introductions of nonindigenous species to the Great Lakes. National Center for Environmental Assessment, Washington, DC. Available

Grigorovich, I.A., Colautti, R.I., Mills, E.L., Holeck, K., Ballert, A.G., and MacIsaac, H.J. 2003. Ballast-mediated animal introductions in the Laurentian Great Lakes: retrospective and prospective analyses. Can. J. Fish. Aquat. Sci. 69: 740-756.

Harris, M.T. and Wheeler, A.W. 1974. Ligula infestation of bleak Alburnus alburnus (L.) in the tidal Thames. Journal of Fish Biology 6(2): 181-188.

Horoszewics, L. 1973. Lethal and ‘disturbing’ temperatures in some species from lakes with normal and artificially elevated temperature. Journal of Fish Biology 5(2): 165-181.

Keckeis, H. and Schiemer, F. 1990. Consumption, growth, and respiration of bleak, Alburnus alburnus (L.), and roach Rutilus rutilus (L.), during ontogeny. Journal of Fish Biology 36(6): 841-851.

Kolar, C.S., and D.M. Lodge. 2002. Ecological predictions and risk assessment for alien fishes in North America. Science 298: 1233-1236.

Kottelat 1997, M. 1997. European freshwater fishes: an heuristic checklist of the freshwater fishes of Europe (exclusive of former USSR), with an introduction for non-systematists and comments on nomenclature and conservation (Vol. 5). Slovak Academy of Sciences.

Kottelat, M. and Freyhof, J. 2007. Handbook of European freshwater fishes. Publications Kottelat: Cornol, Switzerland (646 p).

Kottelat, M. 2012. Conspectus cobitidum: an inventory of the loaches of the world (Teleostei: Cypriniformes: Cobitoidei). The Raffles Bulletin of Zoology 26: 1-199.

Lehtonen, H. 1996. Potential effects of global warming on northern European freshwater fish and fisheries. Fisheries Management and Ecology 3: 59-71.

Leuven, R., Van der Velde, G., Baijens, I., Snijders, J., Van der Zwart, C., Lenders, H.J., and Bij de Vaate, A. 2009. The river Rhine: a global highway for dispersal of aquatic invasive species. Biol. Invasions 11: 1989-2008.

Linden, E., Bengtsson, B.E., Svanberg, O., Sundström, G. 1979. The acute toxicity of 78 chemicals and pesticide formulations against two brackish water organisms, the bleak (Alburnus alburnus) and the harpacticoid (Nitocra spinipes). Chemosphere 8 (11-12): 843-851.

Maceida-Veiga, A., de Sostoa, A., Solorio-Ornelas, E., Monroy, M., Vinyoles, D., Caiola, N., Casals, F., Garcia-Berthou, E., and Munné, A. 2010. Distribution of alien bleak Alburnus alburnus (Linnaeus, 1758) in the Northeastern Iberian Mediterranean Watersheds: past and present.

Mehner, T., Ihlau, J., Dörner, H., and Hölker, F. 2005. Can feeding of fish on terrestrial insects subsidize the nutrient pools of lakes? Limnol. Oceangr. 50(6): 2022-2031.

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Niimi, A.J. and Reid, D.M. 2003. Low salinity residual ballast discharge and exotic species introductions to the North American Great Lakes. Marine Pollution Bulletin 46: 1334-1340.

Perez-Bote, J., Roso, R., Pula, H., Díaz, F., and López, M.T. 2004. Primeras citas de lucioperca, Sander (= Stizostedion) lucioperca (Linnaeus, 1758) y del alburno, Alburnus alburnus (Linnaeus, 1758) en las cuencas extremeñas de los rios Tajo y Guadiana, SO de la Península Ibérica. Anales de Biología 26: 93-100.

Reid, D.F. and Orlova, M. I. 2002. Geological and evolutionary underpinnings for the success of Ponto-Caspian species invasions in the Baltic Sea and North American Great Lakes. Can. J. Fish. Aquat. Sci.59: 1144-1158.

Souchon, Y. and Tissot, L. 2012. Synthesis of thermal tolerances of the common freshwater fish species in large Western Europe rivers. Knowledge and Management of Aquatic Ecosystems 405: 03.

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Welcomme, R.L. (Ed.). 1988. International introductions of inland aquatic species (No. 294). Food & Agriculture Org.

Wheeler, A. 1978. Hybrids of bleak, Alburnus alburnus, and chub, Leuciscus cephalus in English rivers. Journal of Fish Biology 13(4): 467-473.

Willemsen, J. 1980. Fishery-aspects of eutrophication. Hydrobiological Bulletin 14(1-2): 12-21

Vašek, M. and Kubecka, J. 2004. In situ diel patterns of zooplankton consuption by subadult/adult roach Rutilus rutilus, bream Abramis brama, and bleak Alburnus alburnus. Folia Zool. 53(2): 203-214.

Vinyoles, D., Robalo, J.I., de Sostoa, A., Almodóvar, A., Elvira, B., Nicola, G.G., Fernández-Degado, C., Santos, C.S., Doadrio, I., Sardá-Palomera, F., and Almada, V.C. 2007. Spread of the alien bleak Alburnus alburnus (Linnaeus, 1758) (Actinopterygii, Cyprinidae) in the Iberian Peninsula: the role of reservoirs. Graellsia 63(1): 101-110.


Other Resources:

Fishbase. Atherina boyeri. Accessed 05 June 2014

US Fish and Wildlife Service Ecological Risk Screening Summary for Alburnus alburnus

Author: Baker, E., G. Nunez, H. Witman, and J. Li

Contributing Agencies:

Revision Date: 1/23/2015

Citation for this information:
Baker, E., G. Nunez, H. Witman, and J. Li, 2020, Alburnus alburnus (Linnaeus, 1758): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, and NOAA Great Lakes Aquatic Nonindigenous Species Information System, Ann Arbor, MI,, Revision Date: 1/23/2015, Access Date: 7/12/2020

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.