Pathogenicity of Atractolytocestus huronensis (Cestoda) for cultured common carp (Cyprinus carpio L.).

This study presents data on pathogenic effect of a non-native cestode, Atractolytocestus huronensis (Caryophyllidea), on common carp cultured at a fish farm in Croatia. Histopathological examination revealed that A. huronensis causes only local damage within the infected part of the intestine. No differences were observed in pathological effect of the tapeworm on fish of different age classes. In the farm studied, no mortalities or increased losses during wintertime were observed. The cestode was found in all examined age classes (i.e. carp fry, one-year old and two-year old carp), and the intensity of infection ranged from 1 to 183 parasites per fish (mostly 4 to 9). The highest prevalence was observed during August in both one- and two-year old carp, with an absence of parasites in April and during the winter period (end of December).