The change of established fish parasite communities by invasive species such as the goby Blackmouth.
This paper explores the role and prevalence of invasive species introduction on the balance in biodiversity and natural habitats. Different theories are analysed and correlated. These include the dilution effect and spill-back theories. The example used to further study this topic is the goby blackmouth in the Caspian Sea and Danube river and the following species Acanthocephala, Pomphorhynchus laevis, P. tereticollis and Anguillicola crassus [Anguillicoloides crassus].