(tadpole goby), a genus of fishes of the family Cottidae (bullheads). The body length reaches 12 cm. In females and young males the body is covered with bony scutes or granules; adult males are naked. The head is slightly flattened and very large. There are nine species, distributed mostly in the basin of the Caspian Sea. Two species are found in the estuary of the Sea of Azov and the Black Sea. The stellate tadpole goby (B. stellatus) ascends far up the Danube, Dnestr, Iuzhnyi Bug, Dnieper, and Don rivers. The Caspian tadpole goby (B. macrocephalus) ascends the Volga up to Astrakhan. The Volga delta is also the habitat of B. granulosus.
The Russian name for the genus—pygolovki—is often used to designate other members of the family Cottidae..