Latin name

Cyprinus carpio

Other names

European carp, French carp, Italian carp, German carp, Israeli carp, leather carp, mirror carp, king carp, koi, sewer bass, buglemouth; French: carpe, carpe commune; German: karpfen; Japanese: koi; Spanish: carpa.

Identification

The common carp has a thick, moderately elongated body. It has a short head, a rounded snout, a long dorsal fin, a forked tail and relatively large scales. The mouth is toothless and suction cup shaped, adapted to bottom feeding, with the upper jaw slightly protruding from the lower jaw. The mouth has four antennae, two of which are longer and located in the corners of the mouth and shorter on the upper lip. There is a serrated spine on the front of the dorsal and anal fins and two pairs of fleshy barbs on either side of the mouth. The intestines are 2.5-3 times the length of the body. Pigmentation varies from golden olive to brown, with a yellowish tinge to the underside and belly and a reddish tinge to the lower fins. Each scale on the upper flanks of the fish has a concentrated dark spot at the base and a prominent dark rim. Young and breeding males tend to be darker green or grey, with a darker belly rather than yellowish, while females are lighter. Males develop tiny tubercles randomly arranged on the head and pectoral fins. The carp is similar in appearance to a buffalo.

Distribution

It is found in the basins of the Mediterranean, Black, Azov, Caspian and Aral Seas, as well as Lake Issyk-Kul and the rivers of the Pacific Ocean, from the Amur to Burma. As a result of acclimatisation, the carp and its domesticated form have been spread almost all over the world. The carp has been acclimatised to the waters of North America and the Indo-Malay Archipelago. It was one of the first species to be introduced into other countries. Its original range was limited to temperate Asia and the rivers of the Black Sea and Aegean basins in Europe, especially the Danube. At some point the carp found its way to England, and in the 19th century it was introduced from Germany to the United States.

Habitat

Common carp are incredibly hardy and flexible in their habitat preferences. Predominantly bottom dwellers, common carp like quiet, shallow waters with soft bottoms and dense aquatic vegetation. Prefer large, muddy waters but will thrive in small rivers and lakes. Can live in low-oxygen environments and tolerate extremes of temperature, being able to survive in 96°F water for 24 hours. They tend to monopolise some of the waters they inhabit. Carp prefer to spend most of their time in calm, shallow areas with muddy or sandy bottoms. In some northern waters, where fish are abundant and such areas are absent or provide no food, carp will move around shallow, rocky shoals, trotting along the rubble bottom. They are often seen during the day in sheltered areas, sometimes adjacent to deep water, although they are rarely caught in deep water. Carp can live in water with low oxygen levels (around 3-4 mg/l).

Size

Fast growing and moderately large, common carp can reach 80lb, although the average fish is considerably smaller. The record weight per rod and reel for all tackle is 75lb 11oz. The maximum life expectancy is disputed, but can be half a century. The average carp rarely exceeds 15 years. Common carp mature at 3-4 years of age at a length of 35-38cm.

Life history and Behavior

Males are capable of breeding by their second year, while females are capable by the age of 3. Carp spawn in spring and summer, depending on latitude, and become active as soon as the temperature rises to 60°F. During the day or night, several males accompany one or two females to shallow, vegetated water, splashing and thrashing as the eggs are released and fertilised. A large female can carry millions of sticky eggs, but the average number is 100,000 eggs per pound of body weight. The eggs are left unattended and hatch in 3-10 days. Each fry is born with a sticky organ which it immediately uses to cling to the bottom vegetation. After the first day, the fry must come to the surface and take in air to survive. Common carp fry grow rapidly and can reach a length of about 9 inches in their first year of life if they manage to avoid the hungry jaws of their main predators. Juvenile carp make good bait, but their use is banned in some areas where trout are the main species.

Food and feeding habits

Juveniles feed on zooplankton and benthic organisms, while adults feed mainly on benthic organisms. The omnivorous carp prefers a predominantly vegetarian diet, but may feed on aquatic insects, snails, crustaceans, annelids and molluscs. Aquatic plants and filamentous algae are the most popular food groups for carp. Their feeding habits are remarkable in that they rake up sediment from the bottom with their sucking mouth, uprooting and destroying vegetation and muddying the water. They have caused severe habitat damage by killing off large amounts of vegetation. This has had a devastating effect on local fish and other animal populations. Carps spend most of their lives in small groups and tend to wander in search of food. They can grow several kilos a year in rich, fertile environments, but may remain smaller in less fertile and overcrowded environments.

Reproduction

Spawn at a water temperature of at least 15°C, usually 18-20°C (optimum temperature). Spawning occurs in batches, less often simultaneously. The first batch of eggs accounts for up to 80% of the total egg mass. Spawning takes place in the shallow waters of islands and headlands. Spawning is mainly in fresh water, sometimes in brackish water (5%). Spawning takes place on underwater vegetation at a depth of 0.4-1.2 m. Fertility ranges from 90 to 1800 thousand eggs. A fish of 35 cm in length has a fecundity of 200 thousand eggs, while a fish of 55 cm in length has a fecundity of 500 thousand eggs. It spawns in the ponds of fish farms. The eggs are sticky and 1.4-1.5 mm in diameter. The development of the eggs lasts from 3 to 8 days, depending on the water temperature. The length of the larvae at hatching is 4.2-4.4 mm. The hatching pre-larvae hang motionless on the plants. Larvae of 5.5-6.5 mm begin to swim and feed on small zooplankton organisms. At 6.5-7.0 mm the yolk sac dissolves completely. At 19-20 mm the larvae turn into juveniles.

Interesting facts

Modern fish became what they are today through millions of years of natural selection. All fish have evolved and adapted to their environment over time. The external structure of fish is usually due to the development of adaptations related to movement, camouflage, and food capture. For example, in freshwater fish that live in still water - carp, crucian carp, bream - the body is compressed from the sides. This shape facilitates their movement among aquatic plants, helps them to turn in the vertical plane and even protects them from predators who are reluctant to catch fish with a wide body.