Cyprinus carpio Linnaeus, 1758
Conservation status: in Bulgaria: Critically endangered CR [B1ab(i, ii, v); E]; International: IUCN [DD].
General distribution. The drainage basins of the Black Sea, the Caspian Sea and the Aral Sea, the rivers of the Pacific Ocean and Eastern Asia from the Amur River to Burma in the south. It has been artificially introduced to Poland, Germany, Denmark, Sweden, England, Scotland and other countries.
Distribution and abundance in Bulgaria. In the past, it was common in all fresh and brackish water: rivers, marshes and lakes belonging to the basins of the Danube River, the Aegean Sea and the Black Sea [1, 2, 3, 4]. In the middle of the last decade, races of cultivated carp from Romania, the former Yugoslavia, Hungary and other countries were introduced to Bulgaria. Gradually, the cultivated carp was spread all over the Bulgarian water bodies. At present, the wild common carp can be found in Durankulak Lake – in the zone of Orlovo Blato marsh, which in the 1960s was separated by a dike from the rest of the lake, and where cultivated carp has not been introduced [our data]. The wild form is probably also found in some isolated water bodies, such as the Dyavolsko Blato marsh, some river arms, etc.
Habitats. It inhabits lower reaches of rivers, permanent fresh water marshes and lakes and coastal fresh water lagoons.
Biology. The species reaches sexual maturity at the age of 3-4 years . Spawning occurs in the second half of May and June at water temperature of 18°C . Eggs are deposited repeatedly on submerged vegetation. The fecundity varies from 200 000 to 1 200 000 eggs. It feeds on insect larvae, crustaceans, mollusks, worms and aquatic plants [1, 5].
Similar species. The crucian carp (Carassius carassius) and the giebel carp (C. gibelio). The wild common carp can be distinguished by the presence of two pairs of barbels at the corners of the mouth.
Negative factors. Destruction of the spawning grounds as a result of regulation of downstream river courses and draining of marshlands, hybridization with cultivated carp, water pollution, poaching.
Conservation measures taken. The species was listed in the Red Data Book of Bulgaria (1985). Its only confirmed habitat is included within the Durankulak Lake Protected Area.
Conservation measures needed. Imposing a ban on the introduction of the cultivated forms of the species to the natural habitats of the wild common carp.
References. 1. Kovatcheff, 1923; 2. Morov, 1931; 3. Drensky, 1951; 4. Marinov, 1966; 5. Berg, 1949.
Authors: Yanaki Sivkov, Tihomir Stefanov, Teodora Trichkova