Fish helminths in Lithuanian inner waters

During the present investigation, 23 species of fish in Lithuanian inner waters were examined for helminth parasites. Of these, 63 taxa of helminths – 56 taxa of Plathyhelminthes, five of Nematoda, and two of Acanthocephales – were found. Monogenea Gyrodactylus truttae was registered in Lithuania for the first time. Metacercariae of flukes Diplostomum sp., Posthodiplostomum cuticula, and Tylodelphys clavata were found in the highest number of host species: 16, 11, and 12, respectively. A generalized linear mixed model (GLMM) shows that six cyprinid species – Rutilus rutilus, Scardinius erythrophthalmus, Leuciscus leuciscus, Squalius cephalus, Blicca bjoerkna, and Abramis brama – have greater probability of infection with Diplostomum sp. metacercariae. The GLMM also shows that the random effect (the type of Lithuanian inner water body) was statistically significant. Differences in the prevalence of infection with Diplostomum sp., P. cuticula, and T. clavata metacercariae in different water body types were established for some fish species.