Browsing by Author "Hassan, Aziza"

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    Acclimatization, survival and growth. Rates of Pangani tilapia (oreochromis pangani) in different salinities.
    (University of Dar es Salaam, 2011) Hassan, Aziza
    Coastal communities depend on fisheries activities as their main source of income. With the fast rising coastal population and technological advancement, pressure on the wild marine resources is increasing leading to overexploitation. Aquaculture sees as a possible livelihood alternative that will provide the coastal people with an alternative source of income. Some species of tilapia are known to survive and grow in estuarine and marine environment. The aim of this study is to determine the Acclimatization survival and growth of Oreacbromis pangani in four different salinities. Pangani species was collected from Pangani River and acclimatized for 17 days by raising the salinity by 2 PPt /day. The fingerlings weighing between 1 .3g-3 1 .4g were cultured at 0, 15, 25 and 35 ppt in 1 m 3 concrete ponds. Environmental parameters in the ponds were monitored once a day. Water exchange was done at 15% per day throughout the experiment while fecal matter, feeds remains were removed weekly by flushing. The mean growth rates per week were 2.25 ± 2.0 g, 2.77 ± 1.55 g, 2.34 ±1.38 g, and 1.86 g ± 0.16 at salinity level of 0, 15, 25, 35 ppt respectively. The growth rates were not statistically different among salinity levels (1- ANOVA, F =1.129, DF = 55, P > 0.05). Also from one way ANOVA results shows that, there was no significance difference in growth rates between treatments ponds and control ponds for 0, 15 and 25 ppt. However, at 35 ppt stress had impact on growth rate (t, 8.85, P= 0.006). Nevertheless, the results of the study have shown O. pangani to grow better on salinity level of 15. The overall survival rate was 96.46% and that of the different salinities were 100,95,95 and 90 for O, 15, 25 and 35 ppt respectively.