The powan (''Coregonus clupeoides'') is a kind of

freshwater whitefish The freshwater whitefish are fishes of the subfamily Coregoninae, which contains whitefishes (both freshwater and anadromous) and ciscoes, and is one of three subfamilies in the salmon family Salmonidae. Apart from the subfamily Coregoninae, the ...

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 Loch Eck (Gaelic: ''Loch Eich'') is a freshwater loch located on the Cowal peninsula, north of Dunoon, Argyll and Bute, Scotland. It is long. Along with Loch Lomond, it is the only naturally occurring habitat of the Powan (fish).Freyhof, J. & ...

.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 ''Loch Sloy'' was a Scottish sailing barque that operated between Great Britain and Australia from the late 19th century until 1899. Her name was drawn from Loch Sloy, a freshwater loch which lies to the north of the Burgh of Helensburgh, ...

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 l ...

.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 The Eurasian ruffe (''Gymnocephalus cernua''), also known as ruffe or pope, is a freshwater fish found in temperate regions of Europe and northern Asia. It has been introduced into the Great Lakes of North America, reportedly with unfortuna ...

, 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 known from a single lake, and four similar populations in England known as

schelly The schelly (''Coregonus stigmaticus'') is a living fresh water fish of the salmon family, endemic to four lakes in the Lake District, England. Its taxonomy is disputed with some recognizing it as a distinct species and others as a variant of t ...

, are generally considered belonging to the widespread Eurasian

common whitefish ''Coregonus lavaretus'' is a species of freshwater whitefish, in the family Salmonidae. It is the type species of its genus ''Coregonus''. There are widely different concepts about the delimitation of the species ''Coregonus lavaretus'' and abo ...

(''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 The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of ...

, 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 for Phryganea is ''Phryganea grandis ''Phryganea'' is a genus of giant casemakers in the fami ...

'' 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