Ectoparasites Dactylogyrus spp. mainly infest fsh gills and severely damage the host’s
gill tissues. Correspondingly, the explanation of the interaction of fsh with Dactylogyrus
spp. infection is still insufcient. The present study describes the changes in hemato-biochemical, immune, antioxidant, genotoxic, and pathological indices response of Nile tilapia (Oreochromis niloticus) severely (n>50), mildly infected (n=1–50), and uninfected
with Dactylogyrus spp. Data showed the adverse efect of hemato-biochemical indices in
infected fsh compared to uninfected, notably in severely infected O. niloticus. Compared
to uninfected fsh, there is a signifcantly decreased serum lysozyme and complement C3
and increased IgM and phagocytic activity along with signifcant upregulation of (COX-
2), (IL-1β), (TNF-α), and (IL-10) genes in infected fsh partially, in severely infected fsh.
Concisely, indices of antioxidants in the liver and gills marked an increased level of MDA
in the infected fsh compared to the uninfected fsh. Conversely, levels of SOD, CAT, and
GSH were decreased signifcantly with damaged DNA in the gills and liver of infected
groups, particularly in severely infected (P |
