Cytogenetic effect of industrial and agricultural wastes on Tilapia zilli fish

Document Type : Original Article

Authors

1 Zoology Department, Faculty of Science, Benha University, Benha, Egypt

2 Zoology Department, Faculty of Science, Menuifiya University, Menuifiya, Egypt

Abstract

The River Nile and its branches are exposed to many kinds of chemicals and biological pollutants as a result of increasing industrial and biological pollutants and other urbanization activates where effluents are discharged directly into the water without prior treatment.
This study aimed to clarify the effect of environmental pollution (Industrial and agricultural pollutions) on some genetic processes of Tilapiane fish. The study included three groups. The first group was collected from unpolluted locality, the second group collected from downstream to the mouth of agricultural discharge, and the third group was collected from downstream. Chromosomal aberrations were used as an index to evaluate the relationship between the genetic processes and the effect of water pollution. Water analysis was done to water samples from seven localities to determine the following metals iron, lead, cadmium, copper, zinc, mercury and nickel. The results showed that the mean of all metals in the unpolluted water were within the acceptable permissible limit of WHO. In the agricultural polluted water, 100% of water samples exceeding the permissible limit for iron, lead, cadmium, nickel and mercury. Whereas zinc and copper were within the permissible limit. Both industrial and agricultural water, pollutions caused an increase in the frequency of chromosomal aberrations but the frequency in industrial pollution was higher than in agricultural pollution. The types of aberrations observed in this study were structural and numerical aberrations. The predominant types of aberrations by exposure to agricultural pollution were deletion, gap and end to end association and the predominant types of aberrations by exposure to industrial pollution were centromeric attenuation, break and ring. Both industrial and agricultural water pollutions caused a significant increase in the frequency of fragmentation, polyploidy, stickiness and monosomy

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