Histopathological studies on the hematopoietic organs of Clarias gariepinus in relation to water quality criteria at different localities in the River Nile.

Abstract

The physico-chemical parameters (water temperature, electrical conductivity, transparency, pH value, oxygen studies and nutrient salts) were carried out at El Kanater El-Khayria and discharge point of El-Rahawy drain at Rosetta branch of the River Nile seasonally from spring 2011 to winter 2012. In addition, liver, spleen and kidney samples of Clarias gariepinus fish were examined histopathologicaly. The results showed decrease in transparency and nitrite as well as depletion of dissolved oxygen at discharge point of El Rahawy drain. On the other hand, the increase in BOD, COD, ammonia and nitrate at discharge point of El-Rahawy drain was observed. The liver was characterized by vacuolar degeneration, necrosis, hemorrhage, hemolysis, hemosidrin and parasite cysts. The kidney alterations were necrosis, degeneration, dilation of capillaries in the glomerulus and reduction of Bowman´s space. Hemorrhage, hemosidrinosis, degeneration, hemolysis, parasitic forms and necrosis were the most changes in spleen tissue. The collected samples of fish from discharge point of El-Rahawy area were suffered from more pathological changes than those collected from El-Kanater El-Khayria. It was concluded that the discharge of different types of wastes deteriorates the water quality in the River Nile and consequently effect on fauna and fish production. It is recommended to treat the different wastes before discharging to the River Nile stream.