Squalius cephalus
(European chub)

Pictures

Picture	Title	Caption	Copyright
Title Adults Caption European chub (Squalius cephalus); aadult fish on display. Subaqueous Vltava, Prague Czech Republic. April, 2011. Copyright Released into the Public Domain by Karel Jakubec/Prague, Czech Republic	Adults	European chub (Squalius cephalus); aadult fish on display. Subaqueous Vltava, Prague Czech Republic. April, 2011.	Released into the Public Domain by Karel Jakubec/Prague, Czech Republic

Identity

Preferred Scientific Name

• Squalius cephalus (Linnaeus, 1758)

Preferred Common Name

• European chub

Other Scientific Names

• Cyprinus albula Nardo, 1827
• Cyprinus cephalus Linnaeus, 1758
• Cyprinus chub Bonnaterre, 1788
• Cyprinus kietaibeli Reisinger, 1830
• Cyprinus kittaibeli Reisinger, 1830
• Cyprinus lugdunensis Walbaum, 1792
• Cyprinus orthonotus Hermann, 1804
• Cyprinus rufus Vallot, 1837
• Cyprinus salmoneus Gronow, 1854
• Leucalburnus kosswigi Karaman, 1972
• Leuciscus albiensis Valenciennes, 1844
• Leuciscus albus (non Bonaparte, 1838)
• Leuciscus brutius Costa, 1838
• Leuciscus cabeda Risso, 1827
• Leuciscus cabeda pamvoticus (non Stephanidis, 1939)
• Leuciscus cavedanus Bonaparte, 1838
• Leuciscus cephaloides Battalgil, 1942
• Leuciscus cephalus (Linnaeus, 1758)
• Leuciscus cephalus albus Bonaparte, 1838
• Leuciscus cephalus cabeda Risso, 1827
• Leuciscus cephalus cephalus (Linnaeus, 1758)
• Leuciscus cephalus macedonicus Karaman, 1955
• Leuciscus cephalus moreoticus (non Stephanidis, 1971)
• Leuciscus cephalus orientalis Nordmann, 1840
• Leuciscus cephalus orientalis aralychensis Barach, 1934
• Leuciscus cephalus orientalis ardebilicus Barach, 1934
• Leuciscus cephalus orientalis kaznakovi Berg, 1912
• Leuciscus cephalus orientalis thracica Drensky, 1930
• Leuciscus cephalus orientalis thracicus Drensky, 1930
• Leuciscus cephalus orientalis zangicus Barach, 1934
• Leuciscus cephalus ruffoi Bianco & Recchia, 1983
• Leuciscus cephalus wjatkensis Lukasch, 1925
• Leuciscus chub pictava De la Pylaie, 1835
• Leuciscus cii (non Richardson, 1857)
• Leuciscus fellowesii Günther, 1868
• Leuciscus frigidus Valenciennes, 1844
• Leuciscus latifrons Nilsson, 1855
• Leuciscus nothulus Bonaparte, 1841
• Leuciscus orientalis Nordmann, 1840
• Leuciscus orientalis pursakensis Hanko, 1924
• Leuciscus peloponensis (non Valenciennes, 1844)
• Leuciscus rissoi Schinz, 1840
• Leuciscus ruffoi Bianco & Recchia, 1983
• Leuciscus squalius Valenciennes, 1844
• Leuciscus svallize zrmanjae risae Vladykov & Petit, 1930
• Squalius agdamicus (non Kamensky, 1901)
• Squalius berak Heckel, 1843
• Squalius cephaloides (Battalgil, 1942)
• Squalius cephalopsis Heckel, 1843
• Squalius cephalus (Linnaeus, 1758)
• Squalius cephalus athurensis Roule & Cardaillac de Saint-Paul, 1903
• Squalius cephalus cavedanus prespensis Karaman, 1924
• Squalius cephalus vardarensis (non Karaman, 1928)
• Squalius clathratus Blanchard, 1866
• Squalius meridionalis Blanchard, 1866
• Squalius meunier Heckel, 1852
• Squalius orientalis (non Heckel, 1847)
• Squalius orientalis (Nordmann, 1840)
• Squalius pareti Bonaparte, 1841
• Squalius turcicus (non De Filippi, 1865)
• Squalius turcicus platycephala Kamenskii, 1897
• Squalus tyberinus Bonaparte, 1841

International Common Names

• English: English chub; vardar chub
• Spanish: bagre
• French: cabot; chavasson; chevaine; chevesne; chovaine; juègne; meunier; mulet
• Russian: golavl; govali

Local Common Names

• Albania: blyshi; kleni; mëlyshi
• Austria: Döbel
• Belgium: kopvoorn; meun
• Bulgaria: rechen cefal; rechenclen
• Czech Republic: dyblink; jelec; klen; tloušt
• Denmark: almindelig døbel
• Finland: turpa
• Germany: Aitel; Aitel; Alsert; Breitschädel; Butt; Hässel
• Italy: cavedano
• Netherlands: Kopvoorn; meun
• Portugal: escalo
• Spain: bagra
• Sweden: färna
• Turkey: kepenez; talisu kefali
• UK: chub; round chub, fat chub, chevin, pollard

Summary of Invasiveness

The chub is a European freshwater cyprinid which has been reported as an invasive species in Italy and targeted for removal from a river system where introduced in Ireland. It is a long lived fish and has high mobility due to its pelagic condition. Humans may also facilitate its spread due to its value as a game or bait species in recreational fishing. It is also considered a valuable food resource in some regions, although the flesh is of poor quality (Dahl and Medem, 1964).

S. cephalus has ecological characteristics associated with invasiveness. It is omnivorous, and its food sources range from small (i.e. detritus, plants, invertebrates) to large (i.e. tadpoles, small fish) items. In addition it has high fecundity, fast growth rate, and is considered tolerant of anthropogenic pressures. However, there are few reports of impacts in its introduced range and indeed the changes in the taxonomic status of the species make it difficult to identify introduced populations.

Taxonomic Tree

• Domain: Eukaryota
•     Kingdom: Metazoa
•         Phylum: Chordata
•             Subphylum: Vertebrata
•                 Class: Actinopterygii
•                     Order: Cypriniformes
•                         Family: Cyprinidae
•                             Genus: Squalius
•                                 Species: Squalius cephalus

Notes on Taxonomy and Nomenclature

Squalius cephalus has long been considered to be widely distributed throughout most of Europe, from the Iberian Peninsula to the Urals, the Caspian Sea basin and central Iran. For a long time, many Squalius populations in the Mediterranean basin have attracted little attention and they have been uncritically identified as S. cephalus or dumped into a “S. cephalus complex” or “S. cephalus species group”.

Several peri-Mediterranean populations are now considered morphologically and genetically distinct enough to be considered valid species or subspecies. Some morphological characters may be difficult to identify in live fish and, in particular, in juveniles: therefore, genetic analysis is recommended for correct identification. The recent description of new species and the previous wide range of S. cephalus makes the identification of introduced populations in Europe difficult.

Description

The chub (S. cephalus) is a freshwater fish species (Cyprinidae family) that inhabits slow and moderate water flows from a wide range of European waters. It has 3 dorsal spines in total, 7-9 dorsal soft rays, 3 anal spines, 7-10 anal soft rays and 42-48 vertebrae. The mean size is 30.0 cm TL male/unsexed (Muus and Dahlström, 1968) and the maximum length reported is 60.0 cm SL male/unsexed (Kottelat and Freyhof, 2007). The maximum age reported is 22 years (Wüstemann, 1995). The maximum published weight is 8.0 kg (Spillman, 1961).

Distribution

Froese and Pauly (2011) describe the distribution as Eurasia: North, Baltic, northern Black, White, Barents and Caspian Sea basins, Atlantic basins southward to Adour drainages (France), Great Britain north to 56°N. Scandinavia: southern Finland, Sweden north to about Stockholm. Mediterranean basin from Var to Hérault (possibly Aude) (France) drainages. Naturally absent from Italy and the Adriatic basin. 

It is reported as introduced in Italy (Kottelat and Freyhof, 2007) and Ireland (Caffrey et al., 2008).

Distribution Table

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

History of Introduction and Spread

A few chub were found in the River Inny, Ireland, and are presumed to have been introduced intentionally by anglers in the late 1990s or early 2000s to improve the diversity of coarse angling species available. While relatively few were captured during a survey in 2006 (17 individuals), those examined were healthy and most were in spawning condition (Caffrey et al., 2008) and an eradication campaign was initiated. Bartley (2006) reported the introduction of Leuciscus cephalus [S. cephalus] to Italy but its origin was not determined. Other possible introductions of this fish species have not yet been reported: recent description of new species and previous wide range makes identification of introduced populations difficult (see Notes on Taxonomy and Nomenclature).

Introductions

Risk of Introduction

The chub is not of interest to the aquarium trade, but is considered a valuable food resource in some countries and also has interest as a game or bait fish species. Therefore, recreational fishing and interconnection of waterways represent the main pathways of introduction into new locations.

Habitat

S. cephalus inhabits pools and tables from small to large rivers, and there are also populations described in lakes or reservoirs. Lake populations migrate to inflowing streams for spawning that preferably takes place in fast-flowing waters with gravel bottoms, rarely among submerged vegetation (Kottelat and Freyhof, 2007).

Adults are usually solitary or occur in small swarms, whereas juveniles form large swarms. Adults are usually found in pools, whereas juveniles live in very shallow shoreline habitats (Kottelat and Freyhof, 2007).

Habitat List

Biology and Ecology

Genetics

Some genetic records were listed with the same values in the River Kupa, South Pyrenees, Yugoslavia and other unspecified localities. Haploid/gametic chromosome number (n) is 25, whereas diploid/Zygotic chromosome number (2n) is 50-50 (Al-Sabti, 1986; Klinkhardt et al., 1995; Arkhipchuk, 1999).

Reproductive Biology

Sokolov and Berdicheskii (1989) reported that spawning occurs in fast-flowing water above gravel bottom, rarely among submerged vegetation. Males reach sexual maturity at the age of 2-4 years whereas females reach it at 4-6. Maturity is influenced by environmental factors and some individuals may mature much later. Spawning takes place in May-August, when temperature rises above 14ºC. Multiple spawning is described during each breeding season. Males assemble at spawning sites and follow ripe females, often with much splashing, to shallow riffles. Females then lay sticky eggs into the gravel (Kottelat and Freyhof, 2007). Pale yellow eggs are found attached to gravel, weed and stones in flowing water (Pinder, 2001). Billard (1997) also reported eggs added to plants.

Fecundity varies seasonally and geographically. The lowest value of fecundity (1158-2050 eggs) was detected in Turkey (Ünver, 1998; Ünlü and Balci, 1993) and the highest values (100,000 eggs) were detected in Europe (Vostradovsky, 1973). Maitland and Campbell. (1992) reported the same maximum values in Western Greece and Peloponnese.

Physiology and Phenology

Tolerant of anthropogenic impacts. Further studies are required.

Longevity

S. cephalus lives up to 15 years, females longer than males (Kottelat and Freyhof, 2007). Maximum reported age is 22 years (Wüstemann, 1995)

Activity Patterns

Potamodromous species.

Population Size and Density

Abundant. Unknown population trend.

Nutrition

Feeds on a wide variety of aquatic and terrestrial animals and plant material. Large individuals are predominantly piscivorous (Kottelat and Freyhof, 2007). In the UK is recorded as feeding on worms, molluscs, crustaceans, and various insect larvae (Maitland and Campbell, 1992); large chub eat considerable numbers of small fish, such as chub, eels, dace, roach, gudgeon and minnows; also frogs, crayfish, voles and young water birds. Further information on natural food sources is as follows:

Environmental Requirements

S. cephalus prefers slow-flowing waters. Although it is considered tolerant to anthropogenic perturbations, large animals may be particularly vulnerable to reduced water flow levels due to the pelagic conditions of the species. Detailed studies on environmental preferences to establish lower and upper tolerance values have not been published. A study performed on Iberian populations of S. laietanus (i.e. formerly S. cephalus) considers the species tolerant to poor water quality and physical habitat degradation gradients (Maceda-Veiga and De Sostoa, 2011).

Latitude/Altitude Ranges

Notes on Natural Enemies

All piscivorous species are the chub’s natural enemies (e.g. birds, mammals, introduced and native piscivorous fish species).

Means of Movement and Dispersal

S. cephalus is a potamodromous species. Migrations take place during the breeding season. It can cover more than 100 km (Riede, 2004). The latitude and longitude migration movements range from 10°W to 60°E and 64°N to 35°N, respectively.

Pathway Causes

Pathway Vectors

Impact Summary

Environmental Impact

The introduction of exotic species may cause hybridization with native species, predation, resource competition and agonistic behaviour with native species and/or the introduction of diseases. Chub does not represent a risk for humans but it may cause changes to ecosystems (i.e. altering food web structures) and it may predate on native species. The risk of hybridization is particularly important with closely related fish species, in particular with other members of the Squalius genus. Fertile hybrids with Alburnus alburnus have also been reported (Kottelat and Freyhof, 2007). Studies on the effects of chub on native fish species are lacking.

Risk and Impact Factors

• Altered trophic level
• Ecosystem change/ habitat alteration
• Modification of natural benthic communities

• Highly likely to be transported internationally deliberately
• Highly likely to be transported internationally illegally
• Difficult to identify/detect in the field
• Difficult/costly to control

Uses

The chub is of no interest to the aquarium trade, but is considered a valuable food resource in some countries despite poor quality of the flesh. It also has interest as a game or bait fish species in recreational fishing.

Uses List

Animal feed, fodder, forage

• Bait/attractant

General

• Sport (hunting, shooting, fishing, racing)

Diagnosis

The similar morphological traits between species of the Squalius genus require the aid of specialists to distinguish between them. The combination of morphological and genetic traits may also be necessary to ensure proper identification (particularly in juvenile specimens) and this procedure may also allow detection of hybrids.

Detection and Inspection

The existence of stowaway species mixed with valuable species in ornamental or any other live fish stocks is not uncommon. The live fish trade therefore requires careful inspection by specialists in order to detect undesirable organisms which are often not labeled. In addition, the regular monitoring of current waters allows managers to detect new fish introductions and to know the spread patterns of exotic species once introduced. This information helps resource managers to identify areas at high risk of invasion and to plan local eradication programs when possible. Electrofishing is a widely recognized method to catch fish without damaging the ecosystem. Nets are a complementary sampling tool for surveys performed in lakes or reservoirs.

Similarities to Other Species/Conditions

Differs from its congeners in France, North, Baltic, Arctic, Black and Caspian Sea basins by possession of the following characteristics: dorsal profile with a well-marked discontinuity between head and trunk; a row of black pigments along free margin of each flank scale, forming a regular reticulate pattern, with no or very few pigments on central part of scales; anal and pelvic fins orange to red; dorsal fin with 8½ branched rays; anal fin with 8½ branched rays (rarely 9½); scales on lateral line 40-45 + 2-3; mouth terminal, with well-marked chin; lower jaw tip not included in the upper lip; interorbital distance 37-42% HL; postorbital distance 47-51% HL; eye diameter 17-22% HL, 1.5-2.3 times in snout length; body depth 22-27% SL; lower jaw long, length greater than depth of operculum; iris whitish; pharyngeal teeth 2,5-5,2; in stretched anal fin of individuals larger than about 15 cm SL, distance between tips of first and last branched rays usually greater than caudal peduncle depth. Size up to at least 600 mm SL (Kottelat and Freyhof, 2007). Caudal fin with 19 rays (Spillman, 1961).

Prevention and Control

Prevention

Education programmes can be used to raise public awareness about the threats of introduced species to ecosystems. Regular monitoring of waters by trained specialists can be used to detect new invaders and newly invaded areas.

Eradication

Once established, complete eradication is almost impossible, particularly in large areas. Local extirpation of introduced fish species may be performed in areas of high conservation value, particularly in small streams where the probability of success increases. In the River Inny, Ireland, a netting and electrofishing campaign has been running since 2006 to control a small number of introduced chub (Caffrey et al., 2008) with the result that none have been detected since 2010 (J Caffrey, Inland Fisheries Ireland, personal communication, 2012).

Control

Physical barriers and rotenone are commonly used to control small fish. Regular removal of specimens in small streams may mitigate the effect of exotic species.

Monitoring and Surveillance

Regular electrofishing surveys.

References

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Anon., 1999. Systematic list of Estonian fishes. World Wide Web Electronic Publication, 14 January 2000. http://bio.edu.ee/animals/Kalad/kalalist2.htm

Appeltans W; Bouchet P; Boxshall GA; Fauchald K; Gordon DP; Hoeksema BW; Poore GCB; Soest RWM van; Stöhr S; Walter TC; Costello MJ, 2011. World Register of Marine Species. http://www.marinespecies.org

Arkhipchuk VV, 1999. Chromosome database. Database of Dr. Victor Arkhipchuk.

Bartley DM, 2006. Introduced species in fisheries and aquaculture: information for responsible use and control. Rome, Italy, FAO: unpaginated.

Billard R, 1997. Les poissons d’eau douce des rivieres de France. Identification, inventaire et repartition des 83 especes. Lausanne: Delachaux and Niestle, 192 pp.

Blanc M; Gaudet JL; Banarescu P; Hureau JC, 1971. European inland water fish: a multilingual catalogue. London: Fishing News (Books) Ltd.

Bogutskaya NG, 1997. Contribution to the knowledge of leuciscine fishes of Asia Minor. An annotated checklist of leuciscine fishes (Leuciscinae, Cyprinidae) of Turkey with descriptions of a new species and two new subspecies. Mitt. Hamb. Zool. Mus. Inst. 94:161-186.

Caffrey JM; Acevedo S; Gallagher K; Britton R, 2008. Chub (Leuciscus cephalus): a new potentially invasive fish species in Ireland. Aquatic Invasions, 3(2):201-209. http://www.aquaticinvasions.ru/2008/AI_2008_3_2_Caffrey_etal.pdf

Dahl G; Medem F, 1964. [English title not available]. (Informe sobre la fauna acuatica del río Sinú.) Informe sobre la fauna acuatica del río Sinú. Bogata, Colombia: Corporacion Autonoma Regional de los Valles del Magdalena y del Sinu-CVM-Depto. de Investigaciones Ictiologicas y Faunisticas, Bogotá, 109 pp.

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FAO-DIAS, 2008. Database on introductions of aquatic species. FAO Fisheries Global Information System. Fisheries and Aquaculture Department, FAO. http://www.fao.org/fi/figis/

Froese R; Pauly D, 2008. FishBase. http://www.fishbase.org

Froese R; Pauly D, 2011. FishBase. http://www.fishbase.org

Gerstmeier R; Romig T, 1998. Die Süßwasserfische Europas: für Naturfreunde und Angler. Stuttgart, Germany: Franckh-Kosmos Verlag, 368 pp.

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Klinkhardt M; Tesche M; Greven H, 1995. Database of fish chromosomes. Westarp Wissenschaften.

Koli L, 1990. Werner Söderström Osakeyhtiö. Helsinki, Finland, 357 pp.

Kottelat M; Freyhof J, 2007. Handbook of European Freshwater Fishes. Cornol, Switzerland: Publications Kottelat, 646 pp.

Maceda-Veiga A; Sostoa A de, 2011. Observational evidence of the sensitivity of some fish species to environmental stressors in Mediterranean rivers. Ecological Indicators, 11(2):311-317.

Maitland PS; Campbell RN, 1992. Freshwater fishes of the British Isles. HarperCollins Publishers, London, UK. 368 pp.

Muus BJ; Dahlström P, 1968. Süsswasserfische. München, Germany: BLV Verlagsgesellschaft, 224 pp.

Pinder AC, 2001. Keys to larval and juvenile stages of coarse fishes from fresh waters in the British Isles [ed. by Sutcliffe DW]. Ambleside, UK: Freshwater Biological Association (FBA), 136 pp.

Ratnasingham S; Hebert PDN, 2007. BOLD : The Barcode of Life Data System (www.barcodinglife.org). Molecular Ecology Notes, 7:355-364.

Reshetnikov YS; Bogutskaya NG; Vasil'eva ED; Dorofeeva EA; Naseka AM; Popova OA; Savvaitova KA; Sideleva VG; Sokolov LI, 1997. An annotated check-list of the freshwater fishes of Russia. J. Ichthyol, 37(9):687-736.

Riede K, 2004. Global register of migratory species - from global to regional scales. Final Report of the R&D-Projekt 808 05 081. Bonn, Germany: Federal Agency for Nature Conservation, 329 pp.

Sokolov LI; Berdicheskii LS, 1989. Acipenseridae. In: The freshwater fishes of Europe. Vol. 1, Part II. General introduction to fishes Acipenseriformes [ed. by Holcík, J.]., Germany: AULA-Verlag Wiesbaden, 150-153.

Spillman C-J, 1961. Faune de France: Poissons d’eau douce. Paris: Fédération Française des Sociétés Naturelles,Tome 65, 303 pp.

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Vostradovsky J, 1973. Freshwater fishes. London, UK: The Hamlyn Publishing Group Limited, 252 pp.

Wüstemann O; Kammerad B, 1995. Der Hasel, Leuciscus leuciscus ([English title not available]). Magdeburg, Germany: Westarp Wissenschaften, 195 pp.

Ünlü E; Balci K, 1993. Observation on the reproduction of Leuciscus cephalus orientalis (Cyprinidae) in Savur stream (Turkey). Cybium, 17(3):241-250.

Ünver B, 1998. An Investigation on the Reproduction Properties of Chub Leuciscus cephalus (L.,1758) in Lake Tödürge (Zara/Sivas). Turkish Journal of Zoology, 22:141-147.

Links to Websites

Organizations

Italy: FAO (Food and Agriculture Organization of the United Nations), Viale delle Terme di Caracalla, 00100 Rome, http://www.fao.org/

Contributors

04/01/12 Original text by: 

Mònica Utjés Mascó, Department of Animal Biology & Research Institute of Biodiversity (IrBio), Faculty of Biology, University of Barcelona, Avda Diagonal, 643. E-08028 Barcelona, Spain

Alberto Maceda Veiga, Department of Animal Biology & Research Institute of Biodiversity (IrBio), Faculty of Biology, University of Barcelona, Avda Diagonal, 643. E-08028 Barcelona, Spain

The names of reviewers are available from CABI on request.

Distribution Maps