Common carp

Description:

Body compressed laterally, moderately elongate, covered with large cycloid scales. Snout blunt, mouth large, inferior. Two pairs of short barbels. Color: dark on back, golden on sides. Belly, pectorals and pelvics - light-yellow, ventral fin orange, caudal fin gray with orange shade. Coloration changes dependent on habitat. Pharyngeal teeth arranged in three rows 1•1•3-3•1•1. Lateral line scales 34-40.

Habitat:

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 naturally live in a temperate climate in fresh or slightly brackish water with a pH of 6.5–9.0 and salinity up to about 5‰, and temperatures of 3 to 35 °C. The ideal temperature is 23 to 30 °C, with spawning beginning at 17–18 °C; they will readily survive winter in a frozen over pond, as long as some free water remains below the ice. Carp are able to tolerate water with very low oxygen levels, by gulping air at the surface.

Notes:

Common carp has been introduced, sometimes illegally, to most continents and some 59 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, disturb and eat submerged vegetation causing serious damage to native duck and fish populations, like canvasbacks.[20] Similar to the Grass Carp, the vegetation they consume is not completly digested and rots, raising the nutritional level of the water and causing excessive algae growth. They destroy nests of other fish and eat their eggs, reducing their numbers significantly. 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.