Benthophiloides brauneri Beling & Iljin, 1927
Conservation status: in Bulgaria: Extinct EX; International: IUCN [DD].
General distribution. A Ponto-Caspian relict species. It is found in the Caspian Sea and in some brackish and fresh water basins and mouths of rivers in the Black Sea basin. It occurs in the lower reaches of the rivers Dnieper and Bug and in the Danube Delta.
Distribution and abundance in Bulgaria. In the past, the species occurred only in Shabla Lake . It was not found in other regions of Bulgaria [2, 3]. In recent years, the species has not been recorded in the lake, and it is considered extinct .
Habitats. It inhabits coastal fresh water and brackish lagoons, as well as sea shallows (at depths of up to 6 m, including sea bays).
Biology. Brauner's goby reaches sexual maturity in the first year at a body length of about 3 cm. Females spawn repeatedly from July to August. They lay their eggs in shallow water, usually under stones or in dead mussel shells. Fecundity ranges between 20 and 50 eggs. The species feeds on worms, mollusks, crustaceans and insect larvae [2, 5, 6, 7].
Similar species. The stellate tadpole-goby (Benthophilus stellatus), from which Brauner's goby is distinguished easily by the absence of a chin barbel and wide dermal fold at angle of jaws, as well as the lack of tubercles on the head and body.
Negative factors. The main factors which caused the disappearance of the species were: loss of habitats associated with changes in the hydrological regime of the wetlands; water pollution; competition with non-indigenous fish species introduced.
Conservation measures taken. The species was listed in the Red Data Book of Bulgaria (1985) and the Red Book of the Black Sea (1999). The only habitat where the species was found is included in the Shabla Lake Protected Area.
References. 1. Gheorghiev, 1953; 2. Stojanov et al., 1963; 3. Gheorghiev, 1966; 4. Vassilev, 1998; 5. Svetovidov, 1964; 6. Banarescu, 1964; 7. Miller (Ed.), 2004.
Authors: Tihomir Stefanov, Yanaki Sivkov, Teodora Trichkova