Toxic effect of silver sulfate on heamtological indices of Nile tilapia fish (Oreochromis niloticus) fed with oyster mushroom (Pleurotus ostreatus) prebiotic

The increase of heavy metals disturbs the aquatic ecosystems by affecting the physiological, biochemical parameters and cells of the aquatic organism and causes a decrease in the immune function of fishes. The aim of this study was to determine toxic effects of silver sulfate toxicity on some blood indices of Nile tilapia fish (Oreochromis niloticus) fed with different levels of oyster mushroom (Pleurotus ostreatus) prebiotic. 120 Nile tilapia fry were fed for 6 weeks in 4 treatments with 0, 0.05, 0.1 and 0.2% of prebiotics Oyster mushrooms. At the end of feeding period, the experimental samples were exposed to silver sulfate for 14 days, and sampling was done at two times (at the end of the feeding period, at the end of the toxicity exposure) and hematological indices were measured. The results showed prebiotic alone had no significant effect on RBC, MCV, hematocrit and hemoglobin (P<0.05). However, the amount of white blood cells, MCH and MCHC significantly increased in the treatments fed with prebiotic 0.2 and exposure. In general, Oyster mushroom powder stimulated the non-specific immunity of tilapia and also reduced the destructive effects caused by silver sulfate on blood indices. In general, the amount of 0.1 and 0.2% oyster mushroom in the exposed treatments was able to improve the normal blood indices of Nile tilapia.