Oxidative stress in the gill tissues of goldfishes (Carassius auratus) parasitized by Dactylogyrus spp.

The aim of this study was to investigate the status of oxidative stress in the gill tissues of goldfishes (Carassius auratus) parasitized by Dactylogyrus spp. We therefore compared the concentrations of malondialdehyde (MDA) and total thiol groups in the gill tissues of parasitized and non- parasitized goldfishes. 15 goldfishes parasitized by Dactylogyrus spp. along with 15 non-parasitized goldfishes were selected for the study. A significant increase in MDA concentration (P < 0.01) and a significant decrease in total thiol groups in the parasitized group, were observed when compared to the non- parasitized group. This is the first study which evaluates the effect of Dactylogyrus spp. on the oxidative stress status of goldfish. The results of the present study revealed that parasitized goldfishes showed more severe oxidative stress and lipid peroxidation than non- parasitized fishes and enhanced lipid peroxidation may be linked to gill damage in goldfishes parasitized by Dactylogyrus spp.