Black-faced blenny 2007) and "T. tripteronotum" (Risso, 1810). Besides "T. delaisi", all species are endemic to the Mediterranean Sea. The species "T. delaisi" is subdivided in two subspecies: "T. delaisi delaisi" in the Mediterranean Sea and "T. delaisi xanthosoma" in the Atlantic Ocean. The subspecies can be distinguished by their courtship behaviour: "T. delaisi delaisi" court in free water and "T. delaisi xanthosoma" stay on the ground for courtship behaviour. The speciation process is still under discussion and several hypotheses have been proposed. Black-faced blenny The black-faced blenny ("Tripterygion delaisi") is a small benthic fish from the family Tripterygiidae (triplefin-blennies). It occurs
Round goby invasive nematode "Anguillicoloides crassus". In the Vistula Lagoon, the most abundant parasites of the round goby are nematodes "Hysterothylacium aduncum" and "Anguillicoloides crassus". 25 species of parasites are noted in the round goby in the Great Lakes. The trematode "D. spathaceum" is most abundant core species overall. Also the cestode "Proteocephalus" sp. and the trematode "Neochasmus umbellus" are rather abundant. The round goby may circumvent more of the metacercariae of "N. umbellus" from completing their life cycle. The parasite “load” on the invasive gobies in the Great Lakes appears relatively low in comparison with their native habitats, lending support to