Crucian Carp
Carassius carassius (Linnaeus, 1758)
Carassius vulgaris Nilss.: Kovatcheff, 1923: 61.
Order Cypriniformes
Family Cyprinidae
Conservation status: in Bulgaria: Endangered EN [B1b (ii, iv)]; International: IUCN [LR/lc].
General distribution. Eastern and Central Europe, Northern Italy, Finland, Middle and Central Asia. It is absent in Western and Southern France, Portugal and Switzerland. It has been introduced to Spain.
Distribution and abundance in Bulgaria. In the past, it was found in the Danube River and adjacent marshes, in the rivers Maritsa and Tundzha, as well as in some rivers and lakes of the Black Sea coast: the Kamchiya River, Durankulak Lake and Beloslav Lake [1, 2, 3, 4]. In recent years, it has been recorded in the lower reaches of the rivers Iskar, Vit, Osam and Yantra [5], in the Kamchiya River near Staro Oryahovo, the Mandra Reservoir [6], Srebarna Lake [7] and the reservoirs Ivaylovgrad, Studen Kladenets and Kardzhali [8]. It has also been recorded in some of the Danube marshes, such as: Kalimok, Belene, Orsoya fish ponds, etc. (our data).
Habitats. It is found in permanent rivers, permanent fresh water lakes and marshes, and in coastal fresh water lagoons.
Biology. The crucian carp reaches sexual maturity at the age of 3-4 years, depending on environmental conditions [9]. It spawns repeatedly from June to August. Eggs are deposited on submerged vegetation. Fecundity ranges from 100 000 to 300 000 eggs [1]. It feeds on different benthic invertebrates: crustaceans, insect larvae, mollusks, worms, as well as algae [9].
Similar species. The giebel carp (Carassius gibelio). The crucian carp is distinguished by the shorter and deeper head, the deeper body and the shorter dorsal fin.
Negative factors. The main threats to the species are draining of riverside and coastal marshes and lakes, water pollution, and its gradual displacement by the giebel carp, which ecologically is a much more plastic species.
Conservation measures taken. None.
Conservation measures needed. Development and implementation of an Action Plan for the protection of the species in Bulgaria. Captive breeding and reintroduction of the species into some of its natural habitats, such as Srebarna Lake, Durankulak Lake, etc.
References. 1. Kovatcheff, 1923; 2. Morov, 1931; 3. Stojanov et al., 1963; 4. Drensky, 1951; 5. Karapetkova, 1994; 6. Sivkov, 2003a; 7. Pehlivanov, 2000a; 8. Pehlivanov, 2000b; 9. Zukov, 1965.
Authors: Tihomir Stefanov, Yanaki Sivkov, Teodora Trichkova
