Abstract:
Tilapia is one of the most important aquaculture fish species and it is popularly cultured in all over Bangladesh. The fish is widely consumed by the people for their rich protein content and higher fatty acids. The objective of the present study was to estimate the growth performance, survival rate, fatty acids profiles and fecundity of Nile tilapia. To estimate the effects of different phytoplankton on growth performance and fatty acids composition of Nile tilapia (Oreochromis niloticus) an experiment was conducted for twenty four weeks in concrete small pond located in BCSIR (Bangladesh Council of Scientific and Industrial Research), Dhaka. This study was conducted during the month of May to November, 2015. The fatty acids profile was done in Biological Research Division, Zoology section, BCSIR, Dhaka. The growth performance of Nile tilapia was found to be maximum with Chlorella and lowest with commercial feed that is used as control among four treatments. It can be stated that the growth performance of Nile tilapia could be improved by Chlorella and Spirulina with supplementary feed wheat bran on the basis of Condition factor (k), ADG, SGR (%) and FCR. The findings of the investigation showed thatCondition factor found in treatment T3 with chlorella (1.73±0.02) was significantly higher than that of T1-control (1.56±0.02) at 24 weeksculture period. Specific growth rate of treatment T3 with Chlorella (11.93±0.28) was significantly differ than treatment T4 with mixed feed (0.77±0.14) at 24 weeks of rearing. Spirulina has the best proximate composition for human nutritional interest and thus it was found to be better option to produce healthy fish for human consumption. Use of different phytoplankton such as Spirulina, Chlorella and Azolla influence the fatty acid profiles of Nile tilapia. Findings also showed that the amount of Eicosapentaenoic acid in treatment T3 with Chlorella (1.83±0.22) is highly significant than other treatments. The highest amount of Docosapentaenoic acid is found in treatment T3 with Chlorella (2.30±0.07) and lowest in treatment T1 with control (0.88±0.46). The findings of this research suggest that raising Nile tilapia with Chlorella and Spirulina in ponds could help in better growth performance and improve fatty acid composition of Nile tilapia.
