Tentacled blenny deposit their eggs, the males fertilizes the eggs and guards them until they hatch. Tentacled blenny The tentacled blenny ("Parablennius tentacularis") is a species of combtooth blenny most commonly found in all parts of the Mediterranean Sea (except the eastern part), in the Sea of Marmara and the Black Sea, and the east Atlantic near the coast of Portugal, Spain, Canary Islands, and Morocco south to Guinea. This species reaches a length of TL. Found in brackish waters, in estuaries or deltas, this demersal fish can be found in the sand at the bottom of the water in light vegetation.
Round goby Nord-Ostsee (Kiel) Canal. As of 2010, the westernmost site of round goby occurrence in Europe was the Lower River Scheldt, the tidal zone in the river mouth, and Albert Canal, Belgium. In 2011, the round goby began invading the fresh waters of France: the species appeared in the Rhine River (on the border between France and Germany), and in the French part of the Moselle River. In total, 52 parasite species are registered in the round goby in the native area. Most abundant parasites of the Black-Sea round goby are metacercariae of trematodes of Heterophyidae family, such as "Cryptocotyle concavum",