Misgurnus fossilis (Linnaeus, 1758)
Conservation status: in Bulgaria: Endangered EN [A1a; B1b], BDA-II; International: IUCN [LR/nt], BeC-III, HD-II.
General distribution. Central and Northern Europe – from France to Russia.
Distribution and abundance in Bulgaria. It was found in the Danube River and adjacent marshes, as well as in the lower reaches of some of its tributaries: the rivers Voynishka, Iskar, Vit, Ogosta, Osam, Yantra, Rusenski Lom [1, 2, 3, 4, 5, 6]. There are data that in the past, it ran far upstream the rivers: in the Iskar River it was caught near Roman  and in the Yantra River near Byala . It was also recorded in Srebarna Lake , Shabla Lake [8, 9] and in the Struma River basin . A rare species with declining abundance. At present, it is found only in the Danube River and the adjacent wetlands – the Orsoya fish ponds, Belene, Kalimok and probably elsewhere [our data]. It is extinct in the Struma River basin [our data] and in Srebarna Lake ; its occurrence in Shabla Lake needs confirmation.
Habitats. Permanent rivers and permanent fresh water lakes and marshes. In the past, it was also found in coastal fresh water lagoons.
Biology. It inhabits standing and slow-flowing waters, with sandy or muddy bottom, where it stays buried during the day and when the conditions are unfavouarble (drought). It is sensitive to changes in the atmospheric pressure. It feeds on insect larvae and mollusks [12, 13].
Similar species. None.
Negative factors. The species is sensitive to pollutants which accumulate in the sediment . Another threat is the loss of habitats as a result of draining of marshlands.
Conservation measures taken. The species was included in Annex II of the Biological Diversity Act (2002).
Conservation measures needed. Development and implementation of an Action Plan for the protection of the species in Bulgaria. Restoration and preservation of the wetlands along the Danube River.
References. 1. Kovatcheff, 1923; 2. Drensky, 1928; 3. Drensky, 1951; 4. Marinov, 1978; 5. Karapetkova, 1972; 6. Karapetkova, 1994; 7. Bulgurkov, 1958; 8. Gheorghiev, 1967; 9. Vassilev, 1998; 10. Yankov, 1971; 11. Pehlivanov, 2000; 12. Karapetkova, Zivkov, 1995; 13. Froese, Pauly, 2006.
Authors: Tihomir Stefanov, Teodora Trichkova