HISTOPATHOLOGICAL ASPECTS CAUSED BY NEMATOD PARASITE Eustrongylides excisus OBSERVED IN SOME FISH SPECIES OF EĞIRDIR LAKE, TURKEY

Abstract

The present study was carried out between January and October 2018, in order to determine the infection of Eustrongylides excisus Jägerskiöld, 1909 in some fish species inhabiting Eğirdir Lake - the second largest freshwater lake of Turkey. Parasite infection was detected in host species belonging to Konya tooth-carp (Aphanius iconii Akşiraz, 1948), Big-scale sand smelt (Atherina boyeri Risso, 1810), Caucasian dwarf goby (Knipowitschia caucasica Berg, 1916) and pike-perch (Sander lucioperca Linnaeus, 1758). The highest prevalence of infection (21.4%) was determined in S. lucioperca. The mean intensity ranged from 1.25 nematode/fish in K. caucasica to 2.3 nematodes/fish, in S. lucioperca. The nematode E. excisus was recorded for the first time on Caucasian dwarf goby, a non-native fish species in Eğirdir Lake. In addition, this research provides useful data regarding histopathology effects of E. excisus in all studied teleost species. Hyperaemia, edema, microhaemorrhages, inflammatory reaction and necrosis were observed around the encysted parasites.