Pontic Shad
Alosa pontica (Eichwald, 1838)
Clupea pontica Eichwald, 1838: Drensky, 1923: 72; Caspialosa pontica (Eichwald, 1838): Drensky, 1931: 8; Alosa kessleri pontica (Eichwald, 1838): Stojanov et al., 1963: 51.
Order Clupeiformes
Family Clupeidae
Conservation status: in Bulgaria: Vulnerable VU [A1b, c], BDA-II, IV; International: IUCN [DD], BeC-III, HD-II, V.
General distribution. The Black Sea and the Sea of Azov, entering their bigger tributaries, the rivers Dniester, Bug, Dnieper, Don, Danube, etc., for spawning. In the Danube River, in the past, it reached upstream as far as Hungary, and at present, only as far as the mouth of the Timok River.
Distribution and abundance in Bulgaria. In the past, it was a common species along the Bulgarian Black Sea coast during March and April, and in the Danube River - during May [1, 2, 3, 4]. It has been recorded in the Danube River [5, 6], Varna Lake [7] and the lower reaches of the rivers Kamchiya, Ropotamo, Karaagach and Veleka [8, 9, 10, 11]. Recently, it was found near Kaliakra [12], Varna Bay [13] and the Ropotamo River [14]. Its occurrence in the rivers Veleka and Karaagach has not been confirmed [15, 16]. The abundance of the species has declined considerably [12, 13]. In the period from 2002 to 2005, its annual catch in the Black Sea and the Danube decreased 2.5-fold [17].
Habitats. The main habitats of the species are in the open sea and in the permanent large rivers.
Biology. An anadromous fish. It winters in the sea, and enters the bigger rivers for spawning. The eggs are released from April to July at water temperature of 17-22°C [18]. The fecundity of females ranges from 20 800 to 289 400 eggs [19]. The fertilized eggs are bathypelagic and develop while floating downstream in the rivers. The larvae feed on worms and algae, and the adults feed on crustaceans and fish (sprat, anchovy, sand smelt) [20].
Similar species. The Black Sea shad (Alosa maeotica) and the Caspian shad (A. caspia). The Pontic shad differs from them by the bigger sizes and the moderate number of gill rakers (45-61).
Negative factors. The main threats are water pollution and overfishing.
Conservation measures taken. The species is listed in Annexes II and IV of the Biological Diversity Act (2002).
Conservation measures needed. Protection of the habitats of the species against pollution and strict control of observing the fishing regulations.
References. 1. Kovatcheff, 1923; 2. Drensky, 1923; 3. Drensky, 1931; 4. Drensky, 1951; 5. Marinov, 1966; 6. Kolarov, 1978; 7. Gheorghiev, 1967; 8. Karapetkova, Pechev, 1973; 9. Karapetkova, 1974; 10. Karapetkova, 1975; 11. Karapetkova, 1976; 12. Sivkov, 2000; 13. Sivkov, 2003; 14. Pehlivanov, 1999; 15. Karapetkova et al., 2003; 16. Trichkova et al., 2006; 17. Ministry of Agriculture and Forestry, 2002-2005; 18. Stojanov et al., 1963; 19. Svetovidov, 1964; 20. Hoestlandt, 1991.
Authors: Yanaki Sivkov, Teodora Trichkova
