First record of Dactylogyrus Vastator (Nybelin 1924) (Monogenea: Dactylogyridae) in common carp (Cyprinus Carpio Linnaeus, 1758) from aquaculture facilities in Macedonia

The representatives of the class Monogenea are of great importance in fish pathology. Dactylogyrus vastator (Nybelin 1924) (Monogenea: Dactylogyridae) is a common pathogenic monogenean parasite in common carp (Cyprinus carpio Linnaeus, 1758) from freshwater lakes and cyprinid ponds, worldwide. In our study, a total of 133 specimens of common carp from the cage culture system on Mladost Reservoir (N. Macedonia) were subjected to a parasitological investigation, by seasons. Only fresh fish were subjected to routine identification, dissection, and observation methods. Parasite identification was performed morphologically, based on the character of significant organs, using referent keys for determination. Dactylogyrus vastator was found in winter, on gills of 27 specimens of common carp, with a prevalence of 2.818%, and mean intensity of 6.850. During our research, the presence of Dactylogyrus vastator was found in an aquaculture facility with a very high fish stock density. This parasite species would lead to fish mortality and it depends primarily on the mean intensity, the fish condition, and size, as well as the water temperature and oxygen content. The records of Dactylogyrus vastator in common carp in the present study are considered as the first records in N. Macedonia. The common carp is regarded as a new host for these parasite species in Macedonian aquaculture