Tadpole goby

The tadpole-gobies (Benthophilus), also called pugolovkas (which means "tadpole" in Ukrainian), are a genus of Ponto-Caspian fishes in the family Gobiidae.

They are distributed in the fresh and brackish waters of basins of the Black Sea, Caspian Sea and the Sea of Azov, up to salinities of about 20 ‰. They typically live in habitats such as the deep waters of the Caspian (salinity about 13 ‰) and in the deltas, estuaries and coastal waters of the Ponto-Caspian.

Tadpole-gobies are small fish, never larger than 15 cm, and usually smaller. Their life span is about one year. After spawning they die.