Effect of propolis extract on the parasite load of Nile tilapias reared in cages

Due to increase in demand for healthy and chemical residue-free products, natural therapeutic substances are being enhanced in fish cultivation. Current study evaluates in an unprecedented way (he effect of propolis on the parasite charge of the Nile tilapia (Oreochromis niloticus) reared in fish cages. Six hundred male Nile tilapia (200g) conditioned in ten 1 m3 cages were used. Two treatments with five replications each were provided: TCON: control (extruded meal without propolis) and TPRO: extruded meal with 4% propolis extract. Parasite collection occurred on 0, 35, 70 and 105 days. At the same time, fillet was weighed and fish standard length measured. Temperature was kept within the comfort range for the species during the experimental period ( > 25ºC). Trichodinids and Monogenoids (Dactylogyridae) were detected in the two treatments. There was no statistical difference (p > 0.05) in mean parasite intensity (total parasites/specimens with parasites) and abundance (total parasites/examined specimens) among treatments in the four evaluation periods. Lowest parasite prevalence occurred after 70 days in TPRO (26.66%). There was no statistical difference (p > 0.05) among treatments with regard to fillet weight and standard length of fish. Results show that propolis extract 4% did not significantly affect parasite load, fillet weight and standard length of Nile tilapia.