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Capelin

From Wikipedia, the free encyclopedia
This article is about the fish. For the plant genus, seeMallotus (plant).

Capelin
Scientific classificationEdit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Osmeriformes
Family: Osmeridae
Genus: Mallotus
G. Cuvier,1829
Species:
M. villosus
Binomial name
Mallotus villosus

Thecapelinorcaplin(Mallotus villosus) is a smallforage fishof thesmeltfamily found in theNorth Atlantic,North PacificandArcticoceans.[1]In summer, it grazes on dense swarms ofplanktonat the edge of the ice shelf. Larger capelin also eat a great deal ofkrilland othercrustaceans.Among others,whales,seals,Atlantic cod,Atlantic mackerel,squidandseabirdsprey on capelin, in particular during the spawning season while the capelin migrate south. Capelin spawn on sand and gravel bottoms or sandy beaches at the age of two to six years. When spawning on beaches, capelin have an extremely high post-spawning mortality rate which, for males, is close to 100%. Males reach 20 cm (8 in) in length, while females are up to 25.2 cm (10 in) long.[1]They are olive-coloured dorsally, shading to silver on sides. Males have a translucent ridge on both sides of their bodies. The ventral aspects of the males iridesce reddish at the time of spawn.

Capelin migration

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Migration of Icelandic capelin
Green shade:Feeding area of adults
Blue shade:Distribution of juveniles
Green arrows:Feeding migrations
Blue arrows:Return migrations
Red shade and Red arrows:Spawning migrations, mainspawning groundsandlarvaldrift routes
Atlantic puffinwith capelin in its mouth

Capelin populations in theBarents Seaand aroundIcelandperform extensive seasonalmigrations.Barents Sea capelin migrate during winter and early spring to the coast of northern Norway (Finnmark) and theKola Peninsula(Russia) for spawning. During summer and autumn, capelin migrate north- and north-eastward for feeding.[2]

Icelandic capelin move inshore in largeschoolstospawnand migrate in spring and summer to feed in theplankton-rich oceanic area between Iceland,Greenland,andJan Mayen.Capelin distribution and migration is linked withocean currentsand water masses. Around Iceland, maturing capelin usually undertake extensive northward feeding migrations in spring and summer, and the return migration takes place in September to November. The spawning migration starts from north of Iceland in December to January. In 2009, researchers from Iceland made an interacting particle model of the capelin stock around Iceland, successfully predicting the spawning migration route for the previous year.[3]

Reproduction

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As anr-selectedspecies, capelin have a high reproductive potential and an intrinsic population growth rate.[4]They reproduce byspawningand their main spawning season occurs in spring but can extend into the summer. The majority of capelin are three or four years old when they spawn.[2]The males migrate directly to the shallow water of fjords, where spawning will take place, while the females remain in deeper water until they are completely mature. Once the females are mature, they migrate to the spawning grounds and spawn.[5]This process usually takes place at night.[2]In the North European Atlantic spawning typically occurs over sand or gravel at depths of 2 to 100 m (7–328 ft),[6]but in the North Pacific and waters offNewfoundlandmost spawn on beaches, jumping as far up land as possible, with some managing to strand themselves in the process.[4][7]Although some other fish species leave their eggs in locations that dry out (a few, such asplainfin midshipman,may even remain on land with the eggs during low tide) or on plants above the water (splash tetras), jumping onto landen masseto spawn is unique to the capelin,grunions,andgrass puffer.[8][9]In beach-spawning capelin populations, after the female capelins have spawned, they immediately leave the spawning grounds and can spawn again in the following years if they survive. The males do not leave the spawning grounds and potentially spawn more than once throughout the season.[5]Beach-spawning male capelin are considered to besemelparousbecause they die soon after the spawning season is over.[2]In ocean spawning capelin populations, it has been observed that both male and female capelin are semelparous and die after spawning.[10]This difference observed between capelin populations shows that capelin are physiologically capable of an iteroparous or semelparous reproductive mode depending on spawning habitat.[10]

Studies on two populations of Newfoundland capelin which spawn in two distinct habitats found a lack of evidence of genetic variability between beach and deep-water spawners.[11]This provides support for the species being facultative spawners. Capelin may select optimal spawning location based on abiotic factors such as temperature range and sediment.[12]The optimal temperature range for capelin eggs that leads to greatest hatching success and offspring quality appears when eggs are incubated between 5 and 10 °C (41 and 50 °F).[12]This optimal temperature range provides support that individual capelin are able to select spawning location based on temperature, as temperature is one of the most variable factors between beach and deep-water spawning habitats for capelin.[12]There is also evidence that shows that temperature is not the only factor at play when it comes to selection of spawning habitat. When both habitats are simultaneously experiencing temperatures in the optimal range, capelin are found to spawn in both habitats.[11]This may be an advantageous strategy that leads to increased fitness.[11]Capelin have been observed to spawn at beaches when deep-water or subtidal habitat is lower than 2 °C (36 °F) and spawn in deep-water habitats when beach habitats temperature is consistently above 12 °C (54 °F).[12]

Diet

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Capelin are planktivorous fishes that forage in the pelagic zone.[13]Studies analyzing diet in populations of capelin in both the arctic marine environment as well as in west Greenland waters show that their diet consists upon primarily euphausiids, amphipods, and copepods.[14][13]As capelin individuals grow, the composition of their diet changes.[14]Smaller capelin primarily consume smaller prey (copepods) and shift their diet towards feeding on primarily larger euphausiids and amphipods as body and gape size increases.[14][13]The sufficient distribution and abundance of these zooplankton is necessary for capelin to meet energy requirements for progressing through many stages of their life cycle.[13]Capelin occupy a similar dietary niche as polar cod, which leads to a potential for interspecific competition between the two species.[13]

Fisheries

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Global capture of capelin in tonnes reported by theFAO,1950–2010[15]

Capelin is an importantforage fish,and is essential as the key food of theAtlantic cod.The northeast Atlantic cod and capelin fisheries, therefore, are managed by a multispecies approach developed by the main resource owners Norway and Russia.

In some years with large quantities ofAtlantic herringin theBarents Sea,capelin seem to be heavily affected. Probably both food competition and herring feeding on capelin larvae lead to collapses in the capelin stock. In some years, though good recruitment of capelin despite a high herring biomass suggests that herring are only one factor influencing capelin dynamics.

In the provinces ofQuebec(particularly in theGaspé peninsula) andNewfoundland and Labradorin Canada, it is a regular summertime practice for locals to go to thebeachand scoop the capelin up in nets or whatever is available, as the capelin "roll in" in the millions each year at the end of May or in early June.[16]

Commercially, capelin is used forfish mealandoilindustry products, but is also appreciated as food. The flesh is agreeable in flavour, resembling herring. Capelinroe(masago) is considered a high-value product in Japan. It is also sometimes mixed withwasabior green food colouring and wasabi flavour and sold as "wasabi caviar". Often,masagois commercialised asebikoand used as a substitute fortobiko,flying fish roe,[17]owing to its similar appearance and taste, although themouthfeelis different due to the individual eggs being smaller and less crunchy than tobiko.

Citations

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  1. ^abFroese, Rainer; Pauly, Daniel (eds.) (2016)."Mallotus villosus"inFishBase.August 2016 version.
  2. ^abcdGjøsæter, H. (1998). "The population biology and exploitation of capelin (Mallotus villosus) in the Barents Sea ".Sarsia.83(6): 453–496.doi:10.1080/00364827.1998.10420445.
  3. ^Barbaro, A.; Einarsson, B.; Birnir, B.; Sigurthsson, S.; Valdimarsson, H.; Palsson, O. K.; Sveinbjornsson, S.; Sigurthsson, T. (2009)."Modelling and simulations of the migration of pelagic fish".ICES Journal of Marine Science.66(5): 826.doi:10.1093/icesjms/fsp067.
  4. ^abRose, G.A. (2005)."Capelin (Mallotus villosus) distribution and climate: a sea 'canary' for marine ecosystem change".ICES Journal of Marine Science.62(7): 1524–1530.doi:10.1016/j.icesjms.2005.05.008.
  5. ^abFriis-Rødel, E. (2002)."A review of capelin (Mallotus villosus) in Greenland waters ".ICES Journal of Marine Science.59(5): 890–896.doi:10.1006/jmsc.2002.1242.
  6. ^Muus, B., J. G. Nielsen, P. Dahlstrom and B. Nystrom (1999).Sea Fish.pp. 98–99.ISBN8790787005
  7. ^Polar Life Canada:Capelin, Mallotus villosus.Retrieved 20 August 2016.
  8. ^Roland, T. (9 April 2010).Running with the Grunion.The Independent. Retrieved 20 August 2016.
  9. ^Martin, K.L.M. (2014).Beach-Spawning Fishes: Reproduction in an Endangered Ecosystem.CRC Press.ISBN978-1482207972.
  10. ^abChristiansen, Jørgen S.; Præbel, Kim; Siikavuopio, Sten I.; Carscadden, James E. (28 May 2008)."Facultative semelparity in capelin Mallotus villosus (Osmeridae)-an experimental test of a life history phenomenon in a sub-arctic fish".Journal of Experimental Marine Biology and Ecology.360(1): 47–55.doi:10.1016/j.jembe.2008.04.003.
  11. ^abcPenton, Paulette M.; McFarlane, Craig T.; Spice, Erin K.; Docker, Margaret F.; Davoren, Gail K. (5 November 2014)."Lack of genetic divergence in capelin ( Mallotus villosus ) spawning at beach versus subtidal habitats in coastal embayments of Newfoundland".Canadian Journal of Zoology.92(5): 377–382.doi:10.1139/cjz-2013-0261.ISSN0008-4301.
  12. ^abcdCrook, Kevin A.; Maxner, Emily; Davoren, Gail K. (1 July 2017). Robert, Dominique (ed.)."Temperature-based spawning habitat selection by capelin (Mallotus villosus) in Newfoundland".ICES Journal of Marine Science.74(6): 1622–1629.doi:10.1093/icesjms/fsx023.ISSN1054-3139.
  13. ^abcdeMcNicholl, D. G.; Walkusz, W.; Davoren, G. K.; Majewski, A. R.; Reist, J. D. (27 November 2015)."Dietary characteristics of co-occurring polar cod (Boreogadus saida) and capelin (Mallotus villosus) in the Canadian Arctic, Darnley Bay".Polar Biology.39(6): 1099–1108.doi:10.1007/s00300-015-1834-5.hdl:1993/31778.ISSN0722-4060.
  14. ^abcHedeholm, R.; Grønkjær, P.; Rysgaard, S. (24 June 2012)."Feeding ecology of capelin (Mallotus villosus Müller) in West Greenland waters".Polar Biology.35(10): 1533–1543.doi:10.1007/s00300-012-1193-4.ISSN0722-4060.
  15. ^Mallotus villosus(Müller, 1776)FAO, Species Fact Sheet. Retrieved April 2012.
  16. ^"They're Back: Capelin are Rolling at Middle Cove Beach".Canadian Broadcasting Corporation.Retrieved9 July2015.
  17. ^"'Tobiko' & 'Ebiko'".Archived fromthe originalon 5 February 2017.Retrieved5 February2017.

General and cited references

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