Stellate Tadpole-Goby
Benthophilus stellatus (Sauvage, 1874)
Benthophilus macrocephalus ponticus Berg, 1916: Drensky, 1931: 17.
Order Perciformes
Family Gobiidae
Conservation status: in Bulgaria: Vulnerable VU [A1a].
General distribution. A Ponto-Caspian relict species. It is found in the basins of the Black Sea, the Sea of Azov and the Caspian Sea.
Distribution and abundance in Bulgaria. It is found only in the Danube River. In the past, it was reported as rare near Svishtov and Nikopol [1, 2, 3, 4, 5]. Later, the species was recorded in the Danube near Vidin, near the mouth of the Vidbol River, near Simeonovo and near Baikal, Svishtov, Ruse and Silistra [6, 7, 8, 9, 10]. At present, it is found rarely in the stretch between Vidin and Kozloduy, and more frequently, but only single specimens, in the stretch between Nikopol and Silistra (near Nikopol, Batin, Sandrovo, Ryahovo, between Pozharevo and Dunavets, Dolno Ryahovo and Vetren) [our data].
Habitats. Coastal lagoons, estuaries and permanent rivers.
Biology. In the rivers, it is found on a muddy substrate, and in the brackish waters, it is found on sand and shell debris. It reaches sexual maturity as early as the first year. Spawning occurs in the period April-July. The fecundity of females ranges from 500 to 2 500 eggs. The males guard the nests where the eggs are deposited. It feeds on mollusks, crustaceans, worms and small fish. The males may reach a maximum body length of 13.5 cm, and females of 11 cm. [11, 12]
Similar species. Another 5 species of the family Gobiidae inhabit the Danube River: the monkey goby (Neogobius fluviatilis), the racer goby (N. gymnotrachelus), the bighead goby (N. kessleri), the round goby (N. melanostomus) and the tubenose goby (Proterorhinus marmoratus). The stellate tadpole-goby is differentiated from them by the broad depressed head and by the body covered with large prominent tubercles with spines on top.
Negative factors. Water pollution. The species is especially sensitive to pollutants accumulated in the bottom sediments [12].
Conservation measures taken. None.
Conservation measures needed. Protection of the Danube River against pollution with oil products, heavy metals and toxic organic compounds.
References. 1. Drensky, 1924a; 2. Drensky, 1924; 3. Drensky, 1931; 4. Drensky, 1948; 5. Drensky, 1951; 6. Gheorghiev, 1966; 7. Marinov, 1966; 8. Michailova, 1967; 9. Vassilev, 1994; 10. Karapetkova, Zivkov, 1995; 11. Punchuk, Miller, 2004; 12. Ragimov et al., 2007.
Authors: Teodora Trichkova, Tihomir Stefanov
