The powan (''Coregonus clupeoides'') is a kind of freshwater whitefish endemic to two lochs in

Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...

Loch Lomond Loch Lomond (; gd, Loch Laomainn - 'Lake of the Elms'Richens, R. J. (1984) ''Elm'', Cambridge University Press.) is a freshwater Scottish loch which crosses the Highland Boundary Fault, often considered the boundary between the lowlands of Ce ...

and Loch Eck.Freyhof, J. & Kottelat, M. (2008
''Coregonus clupeoides''.
In:IUCN Red List of Threatened Species. Version 2010.1. (Accessed 17 April 2010) It has been successfully introduced in two other sites, Loch Sloy and the

Carron Valley Reservoir The Carron (Gaelic: ''Carrann'') is a river in central Scotland, rising in the Campsie Fells and flowing along Strathcarron into the Firth of Forth. It has given its name to several locations in Stirlingshire, as well as a type of cannon, a lin ...

.Vendace and Powan: the Coregonids
Dualchas Nàdair na h-Alba (Scottish Nature Heritage) (Accessed 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. The taxonomic status of the British whitefish populations, including powan, is a matter of debate. Currently the Scottish powan, along with the Welsh

gwyniad The gwyniad (''Coregonus pennantii'') is a freshwater whitefish native to Bala Lake ( cy, Llyn Tegid) in northern Wales. The population is threatened by deteriorating water quality and by the ruffe, a fish introduced to the lake in the 1980s and ...

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'').Winfield, I,J., Fletcher, J.M. (2008
Hydroacoustic assessment of the introduced powan populations of Carron Valley Reservoir and Loch Sloy. Final Report.
Natural Environment Research Council This accords with the close genetic similarity among these units, and the absence of clear morphological differences between them. The

FishBase FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.

and

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

continue to recognize the Scottish powan as a distinct species, ''Coregonus clupeoides''.

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 The brown trout (''Salmo trutta'') is a European species of salmonid fish that has been widely introduced into suitable environments globally. It includes purely freshwater populations, referred to as the riverine ecotype, ''Salmo trutta'' morph ...

(''Salmo trutta''), common roach (''Rutilus rutilus''), other powan and ''

Phryganea ''Phryganea'' is a genus of giant casemakers in the family Phryganeidae. There are about 13 described species in the genus. The type species In zoological nomenclature, a type species (''species typica'') is the species name with which ...

'' larvae, and the adult powan are heavily predated by the

northern pike The northern pike (''Esox lucius'') is a species of carnivorous fish of the genus '' Esox'' (the pikes). They are typical of brackish and fresh waters of the Northern Hemisphere (''i.e.'' holarctic in distribution). They are known simply as a ...

(''Esox lucius'') at breeding time.

References

External links

* {{Taxonbar, from=Q2705955 Coregonus Freshwater fish of Europe Fish described in 1803 Endemic fauna of Scotland