Common carp  (Cyprinus carpio)

Domestic carp: common and widespread: not threatened (2). Wild carp: classified as Vulnerable (VU) on the IUCN Red List (3).

The carp that occurs in Britain today is the most commercially important freshwater fish kept in ponds, and has been selectively bred for centuries. This breeding has led to two main differences between ‘domesticated’ carp and wild carp (which do not occur in Britain); domestic carp have a much faster growth rate and a relatively short body with a high back and deep belly (4). The body is greyish to bronze in colour (2) and two fleshy barbels project downwards at either side of the mouth (4). The number of scales varies greatly, with some individuals (known as leather carp) completely lacking scales (4). The usual form found in Britain is called the king carp, another form, the mirror carp has a single row of large scales along the sides (5).

The carp now has a global distribution, after numerous introductions (2). The supposed original wild European population occurs in the River Danube (2). This original population is now under threat, and therefore currently classified as Vulnerable by the IUCN Red List of threatened species (2) (1)

This hardy fish is able to tolerate a broad range of conditions, but fares best in large bodies of fresh water with slow-flowing or still water, with soft muddy sediments (2).

This species is omnivorous, feeding on aquatic crustaceans, insects, worms, aquatic plants, algae and seeds (2). Its feeding technique, of grubbing around in the sediment and straining food from the mud, has caused problems in areas where the carp has been introduced. As well as uprooting submerged vegetation, it also increases the cloudiness of the water, which can have detrimental effects on native wildlife (2) (6).

In temperate waters, spawning take place during the summer in patches of weeds. A number of males pursue spawning females in the race to fertilise the eggs as they are shed into the water. The sticky yellowish coloured eggs attach to vegetation, and are not guarded by the parents (2). A typical female can lay over a million eggs in one breeding season (2).

By gulping air at the surface, the carp is able to tolerate periods when oxygen levels in the water fall (2). In winter, individuals go into deeper waters which tends to be somewhat warmer than shallow water (2).

This species is not threatened.

Conservation action is not required for this introduced species in Britain.

View information on this species at the UNEP World Conservation Monitoring Centre.

For more on this species see Fishbase:
http://www.fishbase.org/Summary/SpeciesSummary.php?ID=1450