Common carp

[12] The original common carp was found in the inland delta of the Danube River about 2000 years ago and was torpedo-shaped and golden-yellow in colour.

Although this fish was initially kept as an exploited captive, it was later maintained in large, specially built ponds by the Romans in south-central Europe (verified by the discovery of common carp remains in excavated settlements in the Danube delta area).

As aquaculture became a profitable branch of agriculture, efforts were made to farm the animals, and the culture systems soon included spawning and growing ponds.

[21] The largest recorded carp, caught by British angler, Colin Smith, in 2013 at Etang La Saussaie Fishery, France, weighed 45.59 kilograms (100.5 lb).

[citation needed][22] Although tolerant of most conditions, common carp prefer large bodies of slow or standing water and soft, vegetative sediments.

[2] The ideal temperature is 23 to 30 °C (73–86 °F), with spawning beginning at 17 to 18 °C (63–64 °F); they easily survive winter in a frozen-over pond, as long as some free water remains below the ice.

[18] Carp pick up sediment by generating suction and mouth the content to identify and select food items by taste and size.

In commercial operations, spawning is often stimulated using a process called hypophysation, where lyophilized pituitary extract is injected into the fish.

The pituitary extract contains gonadotropic hormones which stimulate gonad maturation and sex steroid production, ultimately promoting reproduction.

Common carp are quite salt tolerant compared to other types of freshwater fish, research studies showed that they can withstand salinity of at least 12g/L (12ppt).

[39] A population of mirror carp in Madagascar (there an invasive species) was found to have reverted to full scale cover after being introduced from France in the early twentieth century.

[40] They believe that the phenotypic reversion was due to compensation by quantitative trait loci as a result of a selective disadvantage for partial scaling in the wild, perhaps related to an impairment in parasite resistance.

In absence of natural predators or commercial fishing, they may extensively alter their environments due to their reproductive rate and their feeding habit of grubbing through bottom sediments for food.

In feeding, they may destroy, uproot, disturb and eat submerged vegetation, causing serious damage to food sources and habitats of native duck (such as canvasbacks) and fish populations.

[41][42] In 2020, scientists demonstrated that a small proportion of fertilized common carp eggs ingested by waterfowl survive passing through the digestive tract and hatch after being retrieved from the feces.

These data indicate that despite the low proportion of eggs surviving the digestive tract of birds, endozoochory might provide a potentially overlooked dispersal mechanism of invasive cyprinid fish.

If proven under natural circumstances, endozoochorous dispersal of invasive fish could be a strong conservation concern for freshwater biodiversity.

[citation needed] Carp were introduced to Australia over 150 years ago but were not seen as a recognised pest species until the "Boolarra" strain appeared in the 1960s.

[50][51] Efforts to eradicate a small colony from Lake Crescent in Tasmania, without using chemicals, have been successful, but the long-term, expensive and intensive undertaking is an example of both the possibility and difficulty of safely removing the species once it is established.

[52] One proposal, regarded as environmentally questionable, is to control common carp numbers by deliberately exposing them to the carp-specific koi herpes virus with its high mortality rate.

[47] In 2016, the Australian Government announced plans to release this virus into the Murray–Darling basin in an attempt to reduce the number of invasive common carp in the water system.

[56] In the late 19th century, they were distributed widely throughout the country by the government as a food fish, but they are now rarely eaten in the United States, where they are generally considered pests.

This method has been shown to reduce their impact within 24 hours and greatly increase native vegetation and desirable fish species.

[citation needed] Common carp are thought to have been introduced into the Canadian province of British Columbia from the neighboring Washington state.

Carp farming is often criticized as an anthropogenic driver of eutrophication of inland freshwater bodies - especially in the Central Eastern European Region (CEER).

There has been some debate between environmentalists and carp farmers concerning eutrophication of water bodies, manifested into lobbying at ministry levels surrounding fishpond legislations.

[66] A Slovak Christmas Eve dinner is quite similar, with soup varying according to the region and fried carp as the main dish.

Painting by Ellen Edmonson
Dutch wild carp
The skeleton of a European carp
European carp x-ray
A 12 lb (5.4 kg) mirror carp
Carp in Lake Powell , Arizona
Carp in the Maribyrnong River , Australia
Carp in the duck pond in Herbert Park , Dublin, Ireland
Koi feeding. The koi are ornamental varieties of domesticated carp and are kept in garden ponds. Although the koi's parent species has been considered the common carp, recent authorities believe it originates from an East Asian carp, possibly Cyprinus rubrofuscus . [ 1 ] [ 5 ]
Global aquaculture production of Common carp ( Cyprinus carpio ) in million tonnes from 1950 to 2022, as reported by the FAO [ 60 ]
Lake Prespa carp, as served
European carp caught with an artificial fly