Some investigations on incidence and infestation level in Cyprinid postodiplostomosis

Abstract

In our study, we sampled 82 fish specimens as follows: 62 rudd ( Scardinius erythrophthalmus ), 8 roach (Rutilus rutilus) and 12 silver bream (Blicca bjoerkna). The sampling was done in A¢aga Mare Lake, Cluj County. The investigations took into account the incidence and infestation levels of fish with Posthodiplostomum cuticola metacercaria. The study results show an incidence of parasitosis of 80.60% for rudd, 75.00% for roach and 25.05% for silver bream. Regarding the intensity of infestation (low, medium and high), low levels of infestation are predominant (rudd - 72%; roach 83.30%; silver bream - 66.60%). The preferred body area for metacercaria (in descending order) are as follows: for rudd - 90.00% on the body, 86.00 on the fins and caudal peduncle, and 28.80% on the head; for roach - 50.00% on the body, 66.00% on the fins and caudal peduncle, and 33.00% on the head; for silver bream - 100.00% on the body, 33.00% on the fins and caudal peduncle, and 33.00% on the head.Histopathological sections were taken from musculocutaneous tissue extracted from the dorsal area of fish which was parasitized with cystic metacercariae. The central points of metacercaria is surrounded by a connective structure in the form of a capsule, in which melanocyte-like cells are predominant. Intracytoplasmically, they show a brown-blackish granular pigment which masks the cell nucleus. Perifocally, the inflammatory cell infiltrate is discreet with few mononuclear heterophile cells. Â