Round goby includes mollusks, crustaceans, worms, fish eggs, zebra mussels, small fish, and insect larvae. Adult round gobies feed mainly on mollusks and other small invertebrates (insects and amphipods) living on the bottom of lakes and streams. At spring, the main items in its diet in the Sasyk Lagoon are "Hydrobia", "Cerastoderma", "Abra". In the same season near the Romanian coasts of the Black Sea the round goby feeds on polychaetes, crustaceans ("Idotea balthica", "Pachygrapsus marmoratus", "Xantho poressa", etc.) and juvenile gobies. Near Sevastopol the round goby feeds on molluscs ("Mytilaster lineatus", "Abra" spp.), but near Karadag except molluscs ("Cerastoderma", "Brachiodontes") were
Grass goby Grass goby The grass goby ("Zosterisessor ophiocephalus") is a species of goby native to the Mediterranean Sea, the Sea of Azov and the Black Sea. It is currently the only known member of its genus. Grass gobies can grow up to long. The head crown, nape, throat, belly, and bases of the pectoral fins are covered by cycloid scales and the gill covers are naked. The abdominal sucker has no blades and does not reach the anus. The mandibulae are protrusive, and the skin soft, with mucus. Their coloration is green-brown, patterned with merging brown spots. The cheeks have round