Urban bank fishing for carp – Washington DC USA

The cypriniformes (family Cyprinidae) are traditionally grouped with the Characiformes, Siluriformes, and Gymnotiformes to create the superorder Ostariophysi, since these groups share some common features. These features include being found predominantly in fresh water and possessing Weberian ossicles, an anatomical structure derived from the first five anterior-most vertebrae, and their corresponding ribs and neural crests. The third anterior-most pair of ribs is in contact with the extension of the labyrinth and the posterior with the swim bladder. The function is poorly understood, but this structure is presumed to take part in the transmission of vibrations from the swim bladder to the labyrinth and in the perception of sound, which would explain why the Ostariophysi have such a great capacity for hearing.[2]

Most cypriniformes have scales and teeth on the inferior pharyngeal bones which may be modified in relation to the diet. Tribolodon is the only cyprinid genus which tolerates salt water. Several species move into brackish water but return to fresh water to spawn. All of the other cypriniformes live in continental waters and have a wide geographical range.[2] Some consider all cyprinid fishes carp[by whom?], and the family Cyprinidae itself is often known as the carp family. In colloquial use, carp usually refers only to several larger cyprinid species such as Cyprinus carpio (common carp), Carassius carassius (Crucian carp), Ctenopharyngodon idella (grass carp), Hypophthalmichthys molitrix (silver carp), and Hypophthalmichthys nobilis (bighead carp). Carp have long been an important food fish to humans. Several species such as the various goldfish breeds and the domesticated common carp variety known as koi have been popular ornamental fishes. As a result, carp have been introduced to various locations, though with mixed results. Several species of carp are listed as invasive species by the U.S. Department of Agriculture,[3] and, worldwide, large sums of money are spent on carp control.

Various species of carp have been domesticated and reared as food fish across Europe and Asia for thousands of years. These various species appear to have been domesticated independently, as the various domesticated carp species are native to different parts of Eurasia. Aquaculture has been pursued in China for at least 2,400 years. A tract by Fan Li in the fifth century BC details many of the ways carp were raised in ponds.[36] The common carp, Cyprinus carpio, is originally from Central Europe.[37] Several carp species (collectively known as Asian carp) were domesticated in East Asia. Carp that are originally from South Asia, for example catla (Gibelion catla), rohu (Labeo rohita) and mrigal (Cirrhinus cirrhosus), are known as Indian carp. Their hardiness and adaptability have allowed domesticated species to be propagated all around the world.

Although the carp was an important aquatic food item, as more fish species have become readily available for the table, the importance of carp culture in Western Europe has become less important. Demand has declined, partly due to the appearance of more desirable table fish such as trout and salmon through intensive farming, and environmental constraints. However, fish production in ponds is still a major form of aquaculture in Central and Eastern Europe, including the Russian Federation, where most of the production comes from low or intermediate-intensity ponds. In Asia, the farming of carp continues to surpass the total amount of farmed fish volume of intensively sea-farmed species, such as salmon and tuna