الفهرس 
Acknowledgements
Particular significance of tilapia in aquacultureOnly 14 pages are availabe for public view
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Abstract
Tilapia zilli is widely distributed and support important commercial fisheries in Egypt. Taking into account the wide spectrum of its economic benefits, it paid greater attention over the time in the aquacultured fish systems.
Triazole fungicides, as PEN, get access into the aquaculture in spray drift or surface run-off after rainfall. The advances in the researches of nanotechnology led to commercialization of nano-formulated fungicides. Most recently, Cu-NP have received much focus owing to its fungicidal properties. Several lines of evidences had been emerged from the previous researches indicating the impacts of different members of triazole family and nanobased fungicides on the physiological parameters of fish. However up to the knowledge of the researcher, this study is considered to be the first one in examining the effect of PEN and Cu-NP on the physiology of Tilapia zilli.
The findings of this study may be valuable in suggesting the alteration in hematological markers, testicular steroid hormones, hepato-renal markers and antioxidant systems as potential risk indicators for fungicide exposure in the aquatic system.
This study aimed to shed light on the effects of PEN and Cu-NP on the hematological indices, reproductive and hepato-renal functions, and oxidant/antioxidant balance in male Tilapia zilli.
To achieve this objective, hematological parameters including RBCs, WBCs and platelet and differential leucocytic count, MN and ENA percentage were investigated. In addition, T, TP, Alb, Glob, TC, TG in serum and AST, ALT, ALP, and LDH in the liver and urea and Cr in the serum were measured. O2- and LPO levels and SOD and CAT activities were analyzed in the liver in addition to NO level in the testis and kidney. Furthermore, histological examinations of testis and liver were carried out.
After 21 days of acclimatization, 180 normal adult Tiapia zilli of both sexes were divided into five groups. Each group consists of three aquaria and each aquarium contains 12 fish. The control group received no treatment; PEN (I) group was exposed to PEN at a dose of 0.8 µg/L; PEN (II) group was exposed to PEN at a dose of 1.6 µg/L; Cu-NP (I) group was exposed to Cu-NP at a dose of 7.5 mg/L; Cu-NP (II) group was exposed to Cu-NP at a dose of 15 mg/L.
At the end of three months exposure, blood samples from 9 male fish per group were taken for measurement of hematological and biochemical parameters. Body weight and length, and testis, liver and kidney weight were recorded for calculation of CF, GSI, HSI and RSI. Testis and liver were dissected out and preserved for the later histological examination.
This study showed the following results:
1. No significant differences in CF and HSI could be found between the different experimental groups. GSI of PEN (I) and PEN (II) groups were significantly higher than that of control group. However, there was no significant change in GSI of Cu-NP (I) and Cu-NP (II) groups as compared to the control group. GSI of Cu-NP (I) and Cu-NP (II) groups were significantly lower than that of PEN (I) group, while GSI of PEN (II) group was significantly higher than that of Cu-NP (I) group. The comparisons between GSI of PEN (I) group and that of PEN (II) group, GSI of PEN (II) group and that of Cu-NP (II) group, and GSI of Cu-NP (I) group and that of Cu-NP (II) group revealed absence of any significant differences.
Regarding HSI, no significant changes could be observed between experimental groups.
In comparison with the control group, RSI of Cu-NP (II) group was significantly decreased and that of PEN (I), Cu-NP (I), and PEN (II) groups showed no significant difference. RSI of Cu-NP (II) group was significantly lower than that of PEN (II) group. There were no significant differences between RSI of each of PEN (I) and Cu-NP (I) groups and that PEN (II) group.
2. Regarding the RBC count, PEN (I), PEN (II), Cu-NP (I) and Cu-NP (II) groups showed a significant reduction when comparing with the control group. The RBC count in the PEN (I) and Cu-NP (I) groups was significantly lower than that in the Cu-NP (II) group. There was no significant difference between the RBC count of PEN (I) group and that of Cu-NP (I) group.
As compared with the control group, the WBC count was significantly increased in the PEN (I), Cu-NP (I), and Cu-NP (II) groups and non significantly changed in the PEN (II) group. PEN (I) and Cu-NP (II) groups showed a greater increase in the WBC count than that observed in Cu-NP (I) group.
Platelet count was significantly increased in the PEN (I), PEN (II) and Cu-NP (II) groups when comparing with that of the control group. No significant difference was found when comparing the platelet count of the control group with that of Cu-NP (I) group.
3. The percentage of neutrophils in the PEN (I), PEN (II) and Cu-NP (II) groups was significantly lower than that in the control group. However, there was no significant difference between the percentage of neutrophils in the Cu-NP (I) group and that in the control group. The percentage of neutrophils in the Cu-NP (I) group was significantly higher than those in PEN (I), PEN (II) and Cu-NP (II) groups. Greater reduction in the percentage of neutrophils was observed in PEN (II) group than that found in Cu-NP (I) and (II) groups. Greater reduction in the percentage of neutrophils was found in PEN (I) group than that noted in Cu-NP (II) group.
On the other hand, comparison of the percentage of eosinophils, basophils and monocytes in the different studied groups revealed absence of significant differences.
As compared with the control group, the percentage of lymphocytes was significantly higher in PEN (I), PEN (II) and Cu-NP (II) groups and non significantly changed in Cu-NP (I) group. The highest increase in the percentage of lymphocytes was observed in PEN (II) group followed in the order by PEN (I) and Cu-NP (II) groups.
4. A significant increase in the percentage of MN in RBCs was observed in PEN (I), PEN (II) and Cu-NP (II) groups when compared with the control group and non significant difference was observed in Cu-NP (I) group. Greater increase in percentage of MN was observed in PEN (II) group than that found in PEN (I), Cu-NP (I) and (II) groups.
The percentage of binucleated cells was significantly higher in PEN (I) and (II) groups in comparison with the control group, while that of Cu-NP (I) and Cu-NP (II) groups showed non significant difference. The percentage of kidney shaped nuclei was significantly increased in PEN (I) and PEN (II) groups, while that of Cu-NP (1) and Cu-NP (II) groups showed non significant change. The highest increase in the percentage of kidney shaped nuclei was observed in PEN (II) group followed in the order by PEN (I) group. No significant difference was observed in the percentage of heart shaped, notched and irregular nuclei in the different experimental groups except PEN (II) group which showed a significant increase in comparison with the control group.
5. There were significant increases in serum T levels in PEN (I), PEN (II) and Cu-NP (I) groups and non significant change in Cu-NP (II) group as compared with that of control group. Serum T levels of PEN (I) and Cu-NP (I) groups were significantly lower than that of PEN (II) group.
6. Regarding the changes in the oxidant/antioxidant parameters of the testes, O2- levels of PEN (I) and PEN (II) groups were significantly lower than that of control group. However, no significant difference was detected between O2- levels of Cu-NP (I) and Cu-NP (II) groups and that of control group. In comparison with PEN (II) group, O2- level of Cu-NP (I) and Cu-NP (II) groups significantly higher but without significant difference with PEN (I) group. The comparison between O2- levels of PEN (I), Cu-NP (I) and Cu-NP (II) groups revealed absence of significant difference.
In comparison with the control group, NO level of Cu-NP (II) group significantly increased while, the other experimental groups showed non significant difference. A significant lower NO level was found in PEN (II) group as compared with PEN (I) and Cu-NP (II) groups. The comparison between NO levels of PEN (I), Cu-NP (I) and Cu-NP (II) groups, and between Cu-NP (I) and PEN (II) groups revealed absence of significant difference.
There were no significant changes in LPO levels and SOD activities among the all experimental groups.
As compared with the control group, CAT activity of PEN (I) and PEN (II) groups significantly decreased, while that of Cu-NP (I) and Cu-NP (II) groups showed non significant difference. A significant lower CAT activity was observed in PEN (I) and PEN (II) groups as compared with Cu-NP (I) and Cu-NP (II) groups. No significant differences were found when comparing CAT activity of PEN (I) group with that of PEN (II) group and Cu-NP (I) group with that of Cu-NP (II) group.
7. Gross degenerative changes in the seminiferous tubules, a decrease in the number of spermatozoa, and haemorrhage were found in the testes of PEN (I) group. Signs of inflammatory reactions appeared obvious in the testes of PEN (II) group in the form of congestion in the seminiferous tubules, haemorrhage, and leucocytic infiltration. The testes of Cu-NP (I) group displayed normal spermatozoa, spermatogonia and spermatocytes, while there was a marked decrease in the number of spermatozoa relative to spermatocytes and spermatogonia. Slight histopathological changes were observed in the testes of Cu-NP (II) group including leucocytic infiltration at the margins while spermatozoa, spermatogonia and spermatocytes still keep their normal appearance
8. There were no significant differences between the serum TP levels of the different experimental groups. Serum Alb levels of PEN (I), Cu-NP (I), and Cu-NP (II) groups were significantly higher as compared to the control group, however PEN (II) showed non significant difference. Regarding serum Glob levels, the comparison between the different experimental groups revealed absence of significant difference.
In comparison with the control group, serum TC levels of PEN (I), PEN (II), and Cu-NP (II) groups significantly decreased and that of Cu-NP (I) group showed non significant difference. No significant change could be observed between the serum TC levels of fungicide exposed groups.
A significant increase in serum TG level was observed in PEN (II), Cu-NP (I) and Cu-NP (II) groups as compared to the control group. While, there were no significant differences between serum TG level of PEN (I) and that of the control group, and between serum TG level of Cu-NP (II) and those of Cu-NP (I) and PEN (II) groups.
9. No significant differences could be found when comparing the hepatic ALT activity of the exposed groups with that of control group. Hepatic ALT activity was significantly lower in PEN (II) than PEN (I), Cu-NP (I) and Cu-NP (II) groups.
Regarding hepatic AST activity, the Cu-NP (I) group was significantly higher while, PEN (II) group was significantly lower than the control group. However, the hepatic AST activity in PEN (I) and Cu-NP (II) groups were not significantly different from those in the control and Cu-NP (I) groups.
There were no significant differences between hepatic ALP activity in the fungicide exposed groups except PEN (II) group and that of the control group. The hepatic ALP activity in PEN (II) group was significantly higher than those in the all other experimental groups.
The hepatic LDH activity of Cu-NP (II) group was significantly higher than that of the control and Cu-NP (I) groups. Hepatic LDH activity of the PEN (I) group was significantly higher than that of Cu-NP (I) group. Comparison of each of PEN (I), PEN (II) and Cu-NP (I) groups with the control group revealed absence of significant differences.
10. Concerning the liver oxidant and antioxidant parameters. O2- level of PEN (I) group was significantly higher in comparison with that of the control group. While, PEN (II), Cu-NP (I), and Cu-NP (II) groups showed non significant difference with that of the control group. In addition, there were no significant differences between the O2- levels of PEN (I) and PEN (II) groups and between each of PEN (I), Cu-NP (I) and Cu-NP (II) groups.
With respect to NO levels, PEN (I) was significantly higher than the control, PEN (II), Cu-NP (I) and Cu-NP (II) groups. The comparison between NO levels of each of PEN (II), Cu-NP (I) and Cu-NP (II) groups and that of the control group revealed absence of significant difference.
As compared to the control group, LPO levels of PEN (I), PEN (II), and Cu-NP (II) groups were significantly decreased but there was no significant difference between that of Cu-NP (I) group and the control group. The LPO level of Cu-NP (I) was significantly higher than those of PEN (I), PEN (II), and Cu-NP (II) groups. LPO levels of PEN (II) and Cu-NP (II) groups were significantly higher than that of PEN (I) group.
CAT activity of PEN (I) and PEN (II) groups was significantly higher than that of the control group. On the other hand, no significant difference was found between the CAT activity of Cu-NP (I) and Cu-NP (II) groups in comparison with that of the control group. CAT activity of Cu-NP (II) group was significantly lower than that of PEN (II) and Cu-NP (I) groups. There was no significant difference between CAT activity of PEN (I) group and that of Cu-NP (I) group.
A significant increase in SOD activity was found in PEN (I) group as compared to the other experimental groups. Relative to the control group, the SOD activity of Cu-NP (I) was significantly decreased while, that of of PEN (II) and Cu-NP (II) groups showed non significant difference. The comparison between the SOD activity of PEN (II), Cu-NP (I) and Cu-NP (II) showed absence of significant difference.
11. Increased vacuolation of hepatocytes, degeneration of nuclei, and congestion in the blood vessels were observed in the liver of PEN (I) group. The liver of PEN (II) group showed necrosis in hepatocytes, batches of haemorrhage, and dilatation of blood vessels. The liver of Cu-NP (I) group showed few vacuolation in hepatocytes, dilatation of blood vessels, and appearance of haemorrhage in the wall of the blood vessels. The liver of Cu-NP (II) group showed increased vacuolation in hepatocytes, degeneration in nuclei, and congestion in blood vessels.
12. The serum urea level of PEN (I) group was significantly higher than the other experimental groups. However, comparison between serum urea levels of PEN (II), Cu-NP (I) and Cu-NP (II) groups and that of the control group revealed absence of significant difference.
Regarding serum Cr level, no significant difference could be found when comparing the different experimental groups.
13. Concerning the changes in the oxidant/antioxidant parameters of kidney, O2- level of PEN (I) group was significantly higher than that of the control group. On the other hand, there were no significant differences when comparing O2- level of PEN (II), Cu-NP (I) and Cu-NP (II) groups with that of the control group. As compared with PEN (I) group, O2- level of Cu-NP (II) group was significantly decreased while that of Cu-NP (I) and PEN (II) groups showed non significant difference.
Concerning LPO level, no any significant difference could be observed between the different experimental groups.
In comparison with the control group, CAT activity was significantly increased in PEN (I), PEN (II) and Cu-NP (I) groups and showed non significant change in Cu-NP (II) group. CAT activity of PEN (I) was significantly higher than that of Cu-NP (II) group. As compared to each of PEN (II) and Cu-NP (I) groups, CAT activities of PEN (I) and Cu-NP (II) groups showed no significant differences.
Relative to the control group, SOD activity of PEN (I) and PEN (II) groups were significantly increased while that of Cu-NP (I) and Cu-NP (II) groups showed non significant difference. SOD activity of PEN (I) group was significantly higher than that of PEN (II), Cu-NP (I) and Cu-NP (II) groups. SOD activity of PEN (II) group was significantly higher than that of Cu-NP (I) and Cu-NP (II) groups. The comparison between SOD activity of Cu-NP (I) and that of Cu-NP (II) revealed absence of significant difference.