Common carp (Cyprinus)
Despite their widespread population, common carp (carp) are not native to North American waters. They were introduced in the United States in the late 1870s after being imported from Asia by way of Europe, particularly from Germany and England. They are an abundant and important food source in Europe, Asia and other parts of the world and have been farmed for as long as 2,400 years. However, in a relatively short span of time, their numbers and distribution have grown dramatically in North America, in many instances dominating their local habitat.
Carp are one of the largest members of the minnow family and a close relative of the goldfish. There are a number of physical characteristics that distinguish them from other fish. Most will have a bronze-gold to gold-yellow color on the side, though some are more olive to brown. Their belly is generally a faded yellow tone. Lower fins often have a reddish tint. Juvenile and breeding males will often have a darker green or gray color with a dark belly. Females tend to be somewhat lighter in color than their male counterparts.
Carp have a short head with a rounded snout. They have no teeth and their sucker-like mouth, which points almost downward, is well adapted to their bottom feeding habits. In addition, they have two barbels, or whiskers, on each side of the mouth.
The front of the dorsal and anal fins have a single jagged spine. The one long dorsal fin has between 17 and 21 rays. Carp have fairly large scales marked by a distinct dark spot at the base and a noticeable dark rim. A forked tail completes the body.
Adult carp are bottom feeders that will consume both plant and animal material but more often select a vegetarian diet of aquatic plants and algae. A preference for vegetation does not prevent common carp from feeding on insect larvae, snails, mollusks, crustaceans and other fish, especially those that are dead and decaying. Their favored feeding areas are quiet, shallow waters with a soft bottom and dense aquatic vegetation, though they will travel widely for food. In the process of feeding, they often uproot and destroy bottom vegetation, causing the water to become murky.
Common carp, although introduced to North America just 125 years ago, are found in large, even excessive, numbers nearly everywhere from central Canada to central Mexico and from the Atlantic to Pacific coasts. They are now one of the most widely distributed fish species in North America and can be found in nearly any type of water throughout the United States.
Carp have thrived in North America due to their ability to tolerate poor water quality and a variety of environmental conditions, including low oxygen levels and high temperatures. They are resilient and adaptable nearly anywhere they are located. Although they prefer warm, muddy waters, they can survive in cool, clear water but do not multiply as quickly. One common factor in their habitat, regardless of temperature, is ready access to organic matter.
As bottom feeders that often root for food, they disturb the sentiment at the bottom of the body of water, which in turn makes it muddy. This is an important protection device as well, since it limits visibility for species that prey on carp. Unfortunately, stirring up sediment can limit the penetration of light needed for plant growth. These factors all contribute to the carps ability to quickly dominate a body of water and crowd out other fish species.
- In North America, carp have been criticized for economic and biological damage because their rapid reproduction and feeding habits are blamed for damaging populations of other game fish, as well as entire habitats.
- Many fishermen consider the carp a pest rather than a sport fish. In Europe and Asia, however, they are the most popular game and food fish.
- Carp have been the target of numerous attempts at eradication, including poisoning programs.
- Carp are often cited as an example of what can happen when introducing a species into a new habitat without careful consideration.