Asp
Aspius aspius (Linnaeus, 1758)
Aspius rapax Agassiz, 1835: Kovatcheff, 1921: 93; Drensky, 1930: 679.
Order Cypriniformes
Family Cyprinidae
Conservation status: in Bulgaria: Vulnerable VU [A1a, c, d], BDA-II; International: IUCN [DD], BeC-III, HD-II.
General distribution. Europe, except for Denmark, France, Great Britain, Switzerland and the southernmost parts of the continent.
Distribution and abundance in Bulgaria. In the past, the species was recorded in the Danube River, the adjacent marshes, and the lower reaches of some of its tributaries: Iskar, Vit and Osam Rivers [1, 2, 3]. It was also recorded in the rivers of the Aegean Sea basin: Struma, Maritsa, Tundzha and Vacha, as well as in the Kamchiya River [1, 3, 4]. Later, it was reported in the Danube River [5, 6], Srebarna Lake [7], the rivers Lom, Ogosta, Iskar, Vit, Osam and Yantra [8, 9, 10, 11, 12, 13], as rare in the Kamchiya River [14], and in the Ovcharitsa Reservoir [15]. In the last 10 years, it has been found in the Danube and its tributaries Ogosta, Iskar and Vit [our data], and in the Aegean Sea drainage basin: the Struma River (one specimen caught near the town of Kresna), the Maritsa River (very rarely near Parvomay) [our data] and the Studen Kladenets Reservoir [16]. Its occurrence in Srebarna Lake has not been confirmed [17].
Habitats. It inhabits the lower reaches of permanent rivers but is also found in estuaries.
Biology. The species reaches sexual maturity at the age of 2-4 years. It migrates upstream of rivers for spawning in the period from April to May. Eggs are layed over stony substrate with strong current and at water temperature of 9-10oC. A piscivorous species. It feeds on fish, insects that fell into the water, and even on small aquatic birds. It reaches a maximum body length of 100 cm and a maximum weight of 9 kg. It has a life span of 11 years. [12, 18].
Similar species. None.
Negative factors. River regulation by dams, barrages and weirs; river silting; water pollution; poaching.
Conservation measures taken. The species was listed in Annex II of the Biological Diversity Act (2002).
Conservation measures needed. Restriction on the construction of dams, barrages and weirs in the rivers Struma and Maritsa, as well as in the Danube tributaries.
References. 1. Kovatcheff, 1923; 2. Drensky, 1930; 3. Drensky, 1951; 4. Kovatcheff, 1921; 5. Marinov, 1966; 6. Vassilev, 1994; 7. Bulgurkov, 1958a; 8. Paspalev, Peshev 1955; 9. Michailova, 1970; 10. Karapetkova, 1972; 11. Karapetkova, 1994; 12. Karapetkova, Zivkov, 1995; 13. Trichkova et al., 2004; 14. Karapetkova, 1974; 15. Zivkov, Grupcheva, 1987; 16. Stefanov, Trichkova, 2005; 17. Pehlivanov, 2000a; 18. Froese, Pauly, 2006.
Authors: Teodora Trichkova, Tihomir Stefanov
