Danube Spined Loach
Bulgarian Spined Loach
Sabanejewia bulgarica (Drensky, 1928)
Cobitis bulgarica Drensky, 1928: Drensky, 1928: 171; Cobitis aurata bulgarica (Drensky, 1928): Karapetkova, 1972: 169; Marinov, 1978: 203.
Order Cypriniformes
Family Cobitidae
Conservation status: in Bulgaria: Vulnerable VU [B1a, b].
General distribution. Europe: an endemic species in the lower reaches of the Danube River. It is found in Serbia, Romania and Bulgaria.
Distribution and abundance in Bulgaria. The species was first described from the Danube River near Vidin [1]. Its occurrence was reported along the entire Bulgarian stretch of the Danube from Vidin to Silistra, entering for reproduction several kilometers upstream the mouths of its bigger tributaries: Ogosta, Iskar, Vit, Osam and Yantra [2, 3]. Later, it was again reported in the Danube [4, 5, 6] and the Yantra River, where it was recorded as far as the village of Polsko Kosovo, over 40 km from the mouth [7]. Recently, it has been found in the Danube [our data]. Its spawning migration upstream the other Danube tributaries has not been confirmed.
Habitats. Permanent large rivers with gravel bottom and fast current.
Biology. A benthic, reophilic species. It inhabits the main channel of the Danube River at depths from 9 to 15 m, sometimes reaching 20 m. In the period May-June, it migrates towards the river mouths for spawning. The eggs are released several kilometers upstream. The larvae hatch in 5-7 days. Shortly after hatching, they return to the Danube again. It feeds on benthic invertebrate animals, mainly during the night. It reaches a maximum length of 10 cm [3, 8].
Similar species. The Balkan spined loach (S. balcanica). The Danube spined loach is distinguished by the comparatively shorter body length and higher body depth, as well as by the lower number of spots, bigger in size, on the sides of the body.
Negative factors. Water pollution; changes in water velocity and silt deposition, as a result of river regulation activities.
Conservation measures taken. None.
Conservation measures needed. Restriction on the construction of dams and weirs; protection of the Danube River and its tributaries against pollution.
References. 1. Drensky, 1928; 2. Drensky, 1948; 3. Drensky, 1951; 4. Marinov, 1978; 5. Sivkov, 1991a; 6. Vassilev, 1994; 7. Karapetkova, 1972; 8. Karapetkova, Zivkov, 1995.
Authors: Tihomir Stefanov, Teodora Trichkova
