powan
{{Short description|Species of fish}}
{{Speciesbox
| image = FMIB 49705 Powan.jpeg
| status = VU
| status_system = IUCN3.1
| taxon = Coregonus clupeoides
| authority = Lacépède, 1803
| synonyms = *Coregonus cepedii Valenciennes, 1848
- Coregonus lacepedei Parnell, 1838
- Coregonus microcephalus Parnell, 1838
| synonyms_ref = {{GBIF|taxon=Coregonus clupeoides Lacepède, 1803|id=2351049|access-date=1 March 2024}}
}}
The powan (Coregonus clupeoides) is a kind of freshwater whitefish endemic to two lochs in Scotland, Loch Lomond and Loch Eck. It has been successfully introduced in two other sites, Loch Sloy and the Carron Valley Reservoir.{{cite web|url=http://www.snh.gov.uk/about-scotlands-nature/species/fish/freshwater-fish/vendace-powan/ |title=Vendace and Powan: the Coregonids|website=Dualchas Nàdair na h-Alba (Scottish Nature Heritage)|access-date= 17 April 2010}}
Powan populations are relatively healthy, but may have been negatively impacted by the introduced ruffe, which eats powan eggs and fry. As a conservation action, an attempt to establish populations in four additional lochs has been undertaken.{{cite news|url=http://www.fishnewseu.com/latest-news/scottish/2800.html |title=Powan project to ensure survival of rare UK fish species|website=fishnewseu.com |date=9 February 2010}}{{cite news|url=http://news.scotsman.com/nature/Hundreds-of-rare-powan-fish.6172052.jp |title=Hundreds of rare powan fish to be released into Loch Lomond in conservation effort |work=news.scotsman.com |date=23 March 2010}}
The taxonomic status of the British whitefish populations, including powan, is a matter of debate. Currently the Scottish powan, along with the Welsh gwyniad known from a single lake, and four similar populations in England known as schelly, are generally considered belonging to the widespread Eurasian common whitefish (Coregonus lavaretus).{{cite tech report|author=Winfield, I,J. |author2=Fletcher, J.M. |year=2008|url=http://nora.nerc.ac.uk/2189/ |title=Hydroacoustic assessment of the introduced powan populations of Carron Valley Reservoir and Loch Sloy. Final Report|institution=NERC/Centre for Ecology and Hydrology|number=LA/C03407/2}} This accords with the close genetic similarity among these units,{{cite thesis |author=Etheridge E.C |year=2009|url=http://theses.gla.ac.uk/1598/01/2009EtheridgePhD.pdf |title=Aspects of the conservation biology of Coregonus lavaretus in Britain |degree=PhD |publisher=University of Glasgow}} and the absence of clear morphological differences between them.{{cite journal|author=Etheridge, E.C.|author2= C. E. Adams|author3= C. W. Bean|author4= N. C. Durie|author5= A. R. D. Gowans|author6= C. Harrod|author7= A. A. Lyle|author8= P. S. Maitland|author9= I. J. Winfield|year=2012|title=Are phenotypic traits useful for differentiating among a priori Coregonus taxa? |journal=Journal of Fish Biology|volume=80|pages=387–407|doi=10.1111/j.1095-8649.2011.03189.x}} FishBase and the IUCN continue to recognize the Scottish powan as a distinct species, Coregonus clupeoides.{{FishBase|genus=Coregonus|species=clupeoides|year=2010|month=March}}
Ecology
This fish is benthopelagic, feeding on the lakebed on insect larvae and crustaceans. In Loch Lomond, this fish exhibits a pattern of daily migration to feeding sites and of seasonal migration to breeding grounds. Before the breeding season, the mature males begin to congregate in deep water near the spawning beds; these are shallow areas of gravel and pebbles washed by waves. In late December and January they move into the shallows where they are joined by the ripe females, and spawning is completed by early February, after which the fish disperse to other parts of the loch. The eggs are eaten by brown trout (Salmo trutta), common roach (Rutilus rutilus), other powan and Phryganea larvae, and the adult powan are heavily predated by the northern pike (Esox lucius) at breeding time.{{cite journal |author=Maitland, Peter S.|title=The Reproduction and Fecundity of the Powan Coregonus clupeoides Lacepède in Loch Lomond, Scotland |url=https://books.google.com/books?id=a2f83FDCXzUC&pg=PA374 |year=1969 |journal=Proc. Roy. Soc. Edinb. B |volume=70 |issue=3 |pages=233–264}}
References
External links
- {{Commons category-inline}}
{{Whitefish}}
{{Endemic biota of Scotland}}
{{Portal bar|Fish|Animals|Biology}}
{{Taxonbar|from=Q2705955}}
Category:Freshwater fish of Europe
Category:Fish described in 1803