The tench or doctor fish (Tinca tinca) is a fresh- and brackish-water fish of the order Cypriniformes found throughout Eurasia from Western Europe including the British Isles east into Asia as far as the Ob and Yenisei Rivers.[3] It is also found in Lake Baikal.[4] It normally inhabits slow-moving freshwater habitats, particularly lakes and lowland rivers.[5][6]

Tench
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cypriniformes
Family: Cyprinidae
Subfamily: Tincinae
Jordan, 1878
Genus: Tinca
Garsault, 1764[2]
Species:
T. tinca
Binomial name
Tinca tinca
Synonyms

Taxonomy

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The tench was first formally described in as Cyprinus tinca by Carl Linnaeus in 1758 in the 10th edition of Systema Naturae with its type locality given as "European lakes".[7] In 1764 François Alexandre Pierre de Garsault proposed the new monospecific genus Tinca, with Cyprinus tinca as the type species by absolute tautonymy.[2] The 5th edition of Fishes of the World classified Tinca in the subfamily Tincinae, alongside the genus Tanichthys,[8] while other authorities classified both these genera in the subfamily Leuciscinae with other Eurasian minnows, but more recent phylogenetic studies have supported it belonging to its own family Tincidae.[9][10] The Tincidae was first proposed as a name in 1878 by David Starr Jordan.[11]

Ecology

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The tench is most often found in still waters with a clay or muddy substrate and abundant vegetation.[12] This species is rare in clear waters across stony substrate, and is absent altogether from fast-flowing streams. It tolerates water with a low oxygen concentration,[3] being found in waters where even the carp cannot survive.[12]

 
On Exhibition "Subaqueous Vltava", Prague

Tench feed mostly at night with a preference for animals, such as chironomids, on the bottom of eutrophic waters[13] and snails and pea clams in well-vegetated waters.[12][14]

Breeding takes place in shallow water usually among aquatic plants where the sticky green eggs can be deposited.[3] Spawning usually occurs in summer,[5] and as many as 300,000 eggs may be produced.[15] Growth is rapid, and fish may reach a weight of 0.11 kg (0.25 lb) within the first year.

Morphology

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Tench have a stocky, carp-like shape and olive-green skin, darker above and almost golden below. The tail fin is square in shape. The other fins are distinctly rounded in shape.[12] The mouth is rather narrow and provided at each corner with a very small barbel.[16]

Maximum size is 70 cm (28 in), though most specimens are much smaller.[17] A record fish caught in 2001 in England had a weight of 15 lb 3.4 oz (6.899 kg).[18] The eyes are small and red-orange in colour.[3] Females can reach weights of around 7 kg (15 lb), although 4 kg (8.8 lb) is considered large. Males rarely reach over 3 kg (6.5 lb).[3] Sexual dimorphism is strong, males can be recognised by having larger, more curved pelvic fins extending beyond the anus[19] and noticeable muscles around the base of these fins generally absent in females. Males also possess a very thick and flattened outer ray to the ventral fins.[16] Adult females may have a more convex ventral profile when compared with males.[17]

The tench has very small scales, which are deeply embedded in a thick skin, making it as slippery as an eel.[16] Folklore has it that this slime cured any sick fish that rubbed against it, and from this belief arose the name doctor fish.[15]

 
Fossil Tinca

Golden tench

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An artificially bred variety of tench called the golden tench is a popular ornamental fish for ponds. This form varies in colour from pale gold through to dark red, and some fish have black or red spots on the flanks and fins. Though somewhat similar to the goldfish, because these fish have such small scales, their quality is rather different.[15]

Economic significance

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Tench are edible, working well in recipes that would otherwise call for carp, but are not commonly consumed.[12] They are shoaling fish that are popular quarries for coarse angling in rivers, lakes and canals.[3] Tench, particularly golden tench, are also kept as ornamental fish in ponds as they are bottom feeders that help to keep the waterways clean and healthy.[20]

Angling

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Large tench may be found in gravel pits or deep, slow-moving waters with a clayey or silty bottom and copious aquatic vegetation. The best methods and bait to catch tench are float fishing and ledgering with a swim feeder using maggots, sweetcorn, pellets, bread, and worms. Fish over 1 kg (2 lb) in weight are very strong fighters when caught on a rod.[15]

References

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  1. ^ Freyhof, J. & Kottelat, M. (2008). "Tinca tinca". IUCN Red List of Threatened Species. 2008: e.T21912A9339248. doi:10.2305/IUCN.UK.2008.RLTS.T21912A9339248.en. Retrieved 19 November 2021.
  2. ^ a b Eschmeyer, William N.; Fricke, Ron & van der Laan, Richard (eds.). "Genera in the family Tinca". Catalog of Fishes. California Academy of Sciences. Retrieved 27 November 2020.
  3. ^ a b c d e f Froese, Rainer; Pauly, Daniel (eds.). "Tinca tinca". FishBase. May 2007 version.
  4. ^ Maxim Anikin, ed. (2020). "Baikal lake fish, fish species of lake". Baikal Royal Safari. Archived from the original on 22 January 2024.{{cite web}}: CS1 maint: unfit URL (link)
  5. ^ a b B. Whitton (1982). Rivers, Lakes and Marshes p 163. Hodder & Staughton, London.
  6. ^ "Tench". BadAngling. Retrieved 2018-07-06.
  7. ^ Eschmeyer, William N.; Fricke, Ron & van der Laan, Richard (eds.). "Species in the genus Tinca". Catalog of Fishes. California Academy of Sciences. Retrieved 23 September 2024.
  8. ^ Nelson, Joseph S.; Grande, Terry C.; Wilson, Mark V. H. (2016). Fishes of the World (5th ed.). Hoboken: John Wiley and Sons. doi:10.1002/9781119174844. ISBN 978-1-118-34233-6.
  9. ^ Schönhuth, Susana; Vukić, Jasna; Šanda, Radek; Yang, Lei; Mayden, Richard L. (2018-10-01). "Phylogenetic relationships and classification of the Holarctic family Leuciscidae (Cypriniformes: Cyprinoidei)". Molecular Phylogenetics and Evolution. 127: 781–799. Bibcode:2018MolPE.127..781S. doi:10.1016/j.ympev.2018.06.026. ISSN 1055-7903. PMID 29913311. S2CID 49292104.
  10. ^ "Family TINCIDAE Jordan 1878 (Tench)". The ETYFish Project. 31 May 2023. Retrieved 23 January 2024.
  11. ^ Richard van der Laan; William N. Eschmeyer & Ronald Fricke (2014). "Family-group names of recent fishes". Zootaxa. 3882 (2): 1–230. doi:10.11646/zootaxa.3882.1.1. PMID 25543675.
  12. ^ a b c d e A. F. Magri MacMahon (1946). Fishlore, pp 156–158. Pelican Books.
  13. ^ Perrow, M. R. (1996). "Factors affecting the habitat selection of tench in a shallow eutrophic lake". Journal of Fish Biology. 48 (5): 859–870. Bibcode:1996JFBio..48..859P. doi:10.1111/j.1095-8649.1996.tb01481.x.
  14. ^ Bronmark, C. (1994). "Effects of Tench and Perch on Interactions in a Freshwater, Benthic Food Chain". Ecology. 75 (6): 1818–1828. Bibcode:1994Ecol...75.1818B. doi:10.2307/1939640. JSTOR 1939640.
  15. ^ a b c d A. Lawrence Wells (date unknown). Observer Book of Freshwater Fishes, pp 101–105. Frederick Warne & Co.
  16. ^ a b c   One or more of the preceding sentences incorporates text from a publication now in the public domainChisholm, Hugh, ed. (1911). "Tench". Encyclopædia Britannica. Vol. 26 (11th ed.). Cambridge University Press. p. 61.
  17. ^ a b G. Sterba (1962). Freshwater Fishes of the World pp 249–250. Vista Books, London.
  18. ^ "Coarse Fish Records as at July 2021" (PDF). British Record Fish Committee. Angling Trust. 19 July 2021. Retrieved 22 January 2024.
  19. ^ Ignacio Fernández; Francisco Javier Toledo-Solís; Cristina Tomás-Almenar; Ana M. Larrán; Pedro Cárdaba; Luis Miguel Laguna; María Sanz Galán; and José Antonio Mateo (Mar 2021). "Skeletal Development and Deformities in Tench (Tinca tinca): From Basic knowledge to Regular Monitoring Procedure". Animals. 11 (3). Basel: 621. doi:10.3390/ani11030621. PMC 7996733. PMID 33652872.
  20. ^ Dick Mills (2000). Understanding Coldwater Fish, p 106. Interpet Publishing. ISBN 1-903098-10-6