Common carp (Cyprinus carpio)
photo by Reaperman
The Common carp or European carp (Cyprinus carpio) is a widespread freshwater fish most closely related to the common goldfish (Carassius auratus), with which it is capable of interbreeding. It gives its name to the carp family Cyprinidae. Common carp are native to Asia and Eastern Europe. It has been introduced into environments worldwide, and is often considered an invasive species.
Koi (nishikigoi) is a domesticated ornamental variety that originated in China but became known to the Western world through Japan.
Variants include the mirror carp, with large mirror like scales (linear mirror - scaleless except for a row of large scales that run along the lateral line; originating in Germany), the leather carp (virtually unscaled except near dorsal fin), and the fully scaled carp.
Common carp can grow to a maximum length of 5 feet (1.5 meters), a maximum weight of over 80 lb (37.3 kg), and an oldest recorded age of at least 65 years. The largest recorded carp, caught by an angler in 2007 at Rainbow lake near Bordeaux, France, weighed 88.6 pounds (40.1 kilograms). The wild, non-domesticated forms tend to be much less stocky at around 20% - 33% the maximum size.
Although they are very tolerant of most conditions, common carp prefer large bodies of slow or standing water and soft, vegetative sediments. A schooling fish, they prefer to be in groups of 5 or more. They natively live in a temperate climate in fresh or brackish water with a 7.0 - 9.0 pH, and an a temperature range of 35.0 - 85.0°F. Common Carp will readily survive winter in a frozen over pond, as long as there remains some free water. Carp can with stand summer water temperatures in the low 90's degrees Fahrenheit for short periods. Ideal temperature is 68 to 75 degrees F.
Common carp are omnivorous. The common carp can eat a vegetarian diet of water plants, but prefers to scavenge the bottom for insects, crustaceans (including zooplankton), benthic worms. They also eat fungi.
An egg-layer, a typical adult fish can lay 300,000 eggs in a single spawning. Although carp typically spawn in the Spring, in response to rising water temperatures and rain fall, carp can spawn multiple times in a season. In commercial opperations spawning is often stimulated by injection. Carp lay eggs by the hundreds of thousands, yet their population remains the same, so the eggs and young must perish in similar vast numbers. Eggs and fry often fall victim to bacteria, fungi, and the vast array of tiny predators in the pond environment. Those fortunate enough to survive to juvenile are preyed upon by other fish such as the northern pike and largemouth bass.
Introduction into other habitats
Common carp have been introduced, sometimes illegally, into many countries. Due to their fecundity and their feeding habit of grubbing through bottom sediments for food they are notorious for altering their environment. In feeding, they may destroy, uproot and disturb submerged vegetation causing serious damage to native duck and fish populations.
Efforts to non-chemically eradicate a small colony from Tasmania's Lake Crescent have been successful, however the long-term, expensive and intensive undertaking is an example of the both the possibility and difficulty of safely removing the species once it is established. It has been proposed, but is regarded as environmentally questionable, to control common carp by deliberate exposure to the common carp specific Koi Herpes Virus with its high mortality rate.
In Australia there is enormous anecdotal and mounting scientific evidence that introduced carp are the cause of permanent turbidity and loss of submergent vegetation in the Murray-Darling river system, with severe consequences for river ecosystems, water quality and native fish species. In Victoria, Australia, Common carp has been declared as noxious fish species therefore there is no restriction on the quantity that a fisher can take. In South Australia, it is an offence for this species to be released back to the wild. An Australian company churns common carp into plant fertilizer.
Common carp were brought to the United States in 1831. In the late 1800s they were distributed widely throughout the country by the government as a foodfish. However, common carp are no longer prized as a foodfish in the United States. As in Australia, their introduction has been shown to have negative environmental consequences and they are usually considered to be invasive species. Millions of dollars are spent annually by natural resource agencies to control common carp populations in the United States.
Common carp are believed to have been introduced into the Canadian province of British Columbia from Washington State. They were first noted in the Okanagan Valley in 1912 as was their rapid growth in population. Carp are currently distributed in the lower Columbia (Arrow Lakes), lower Kootenay, Kettle (Christina Lake), and throughout the Okanagan system.
As food and sport
Cyprinus carpio is the number one fish of aquaculture. The annual tonnage of common carp, not to mention the other cyprinids, produced in China alone exceeds the weight of all other fish, such as trout and salmon, produced by aquaculture world wide.
Common carp are extremely popular with anglers in many parts of Europe, and their popularity as quarry is slowly increasing among anglers in the United States (though destroyed as pests in many areas).Carp are also popular with spear and bow fisherman.
Carp is also eaten in many parts of the world both when caught from the wild and raised in aquaculture. In Germany, Austria, the Czech Republic, Slovakia, Croatia and Poland, carp is a traditional part of a Christmas Eve dinner.
Carp are mixed with other common fish to make gefilte fish, popular in Jewish cuisine.
The Romans farmed carp and this pond culture continued through the monasteries of Europe and to this day. In China and soon after in Japan carp farming took place as early as the Yayoi Period (ca. 300 B.C - 300 A.D.).