Effects of Some Different Water Resources and Their Characteristics on the Body Weight Composition and Meat Values of Nile Tilapia in Sudan

Abstract

The main aim of the present study is to investigate the effect of using the three major different water sources (Jebel Aulia, Sennar and Merowe reservoirs dams) upstream and downstream .Three fish collection sites were designated: as the first site included two collection stations along the White Nile River. The second site included two collection stations that had their water supply along the Blue Nile River. The third site included two collection stations along the River Nile main stream. Water samples were taken randomly from each station regularly every month for one-year (2015) sampling period and testing using water kids aqua zol. Samples of fish were taken also for measuring body weight composition, proximate analysis of fish muscles and carcass, amino acids, fatty acids profiles and heavy metals of water samples and fish meat samples. Statistical analysis were performed using One – way of variance (ANOVA) and Duncan’s multiple Range Test, to determine the differences between treatments means at significance rate of P < 0.05. The standard deviation of treatment means will be also estimated. All statistics were carried out using Statistical Analysis program (SPSS, 19).The results showed in tables 1.2 and 3 indicate that, there was significant difference at p ≤0.5 level for pH in all conditions both upstream and downstream, while there were a significant different in the three localities between Dissolved Oxygen, ammonia, nitrate, alkalinity and phosphorus both upstream and downstream between the three season. D.O is higher in Sennar dam and lower in Jebel Aullia, while alkalinity is higher in Merowe and lower in Jebel Aullia, on the other hand hardness is higher in Merowe and lower in Sennar dam, phosphorus is higher in Jebel Aullia and lower in Merowe downstream in all seasons.. There were a significant difference between moisture in Jebel Aulia downstream (77.00±0.89) is higher than others areas, Sennar and Merowe both upstream and downstream. v Furthermore, dry matter and Crude protein in upstream Merowe dam is very higher (28.66±1.96 and 32.77±0.37) than others areas meant there were significance difference within groups. While, no significant differences were found between ash and Esther extract in all localities areas and within groups. The mean score for Nitrogen free extract were higher Jebel Aulia upstream (36.81±2.81), downstream for Sennar dam and Merowe dam (36.88±2.07 and 36.40±1.63) respectively. The results, as shown in Tables 10,11 and 12 indicate that, there no significant differences were found between Arginine in upstream for all localities, while there were significant difference between Arginine in downstream. There were significant differences between Isoleucine, Leucine, Lysine and Methionine in Jebel Aulia both upstream and downstream. There were significance difference found between, Phenylalnine, Tyrosine and Valine in Jebel Aulia while, no significance difference for others localities.The results, as shown in Tables 16,17 and 18 and figures 16,17 and 18 indicate that, there were a significant difference between Pb of O.niloticus, in Jebel Aulia dam, Sennar dam and Merowe dam, and also within groups upstream and downstream, this mean the result is significant at the p = 0.05 level. Furthermore, no significant differences were found between Cd, Cu and Zn in all localities dams and within groups. The results, as shown in Tables 19, 20 and 21 and figures 19, 20 and 21 indicate that, there were a significant difference between Pb, Cd and Zn in water samples, in Jebel Aulia dam Sennar dam and Merowe dam, but there were no significance difference in Zn upstream and downstream during all seasons. Furthermore, no significant differences were found between Cd, Cu and Zn in all localities dams and within groups.