The quality of water in the aquatic ecosystem is a very sensitive issue and is controlled by many physical and chemical factors. The deterioration of water quality has variable effect on parasitic population and their rate of infestation and consequently the negative impact can impede fish viability and productivity. The current study aimed to: i) Surveying the parasitic isopod infesting some of the edible fish species inhabit the Egyptian Mediterranean Sea water ii) Assess the seasonal variations in water quality parameters of Mediterranean coastal water of Egypt. iii) Investigating the effect of water quality parameters on the rate of parasitic isopod infestation among the examined fishes. Water samples during each season were analyzed for physico-chemical parameters using standard methods. The selected parameters namely: temperature, pH, salinity, oxidizable organic matter (OOM), ammonia, nitrite, nitrate and some heavy metals (Lead, Copper, Arsenic and Mercury). A total of 400 Mediterranean Sea fish of Tilapia zilli, Solea spp, Mugil capito and Sardinella species were examined for isopod parasites. Parasites were preserved and identified. The results revealed isolation of the isopod species Livoneca redmanii, with an infestation rate of 19% among the examined fish species with the highest rate among Mugil capito (36%) and reached its total maximum value during summer (32%). Correlation analysis revealed that infestation rates were highly correlated (positively) with certain water quality parameters, such as temperature, oxidzable organic matter (OOM) and nitrite. High water temperatures during summer and spring seasons, and high nitrite concentrations were significantly associated with high infestation rates in Tilapia zilli (R2=0.91, P=0.046 and R2 = 0.97, P=0.015). The findings suggested that deterioration of water quality with varying seasons was stressful to fish, and consequently increased the incidences of the parasitic Isopod (Livoneca redmanii) so considered as a predisposing agent to parasitism. The study recommended
periodical monitoring of water quality parameters in fish water resources and the need to take all measures by the responsible authorities to prevent pollution of these resources to minimized and control the prevalence of parasite
infestations particularly of isopods.
Mahmoud N. E., Fahmy M. M., Abuowarda M. M., Zaki M. M., Ismael E. & Ismai E. M., 2019. Influence of water quality parameters on the prevalence of Livoneca redmanii (Isopoda; Cymothoidae) infestation of Mediterranean Sea fishes, Egypt. International Journal of Veterinary Science 8 (3): 174-181. Article.
