Performance of rotifer cultured by the newly Isolated Microalgae nannochlolis SP

Abstract

Nannochlorisspis a marine microalgae that has an average size of 2 μm and 48.57 % lipid by dry weight. The objective of this study is to evaluate the nutritional value of Vietnamese Nannochlorissp when used as feed for rotifer Brachionusplicatilis.The experiment had four treatments, different regarding the feed used to culture rotifer. Treatment A used only Nanochlorissp while treatment B used both Nanochlorissp and bakery yeast. Treatment C usedNanochloropsisoculataand bakery yeast. This combination is popularly used for rotifer culture and could be considered as the control. Treatment D used both NanochlorisspandNanochloropsisoculata at a ratio of 1:1 and bakery yeast. The density of microalgae in all treatments was 13-14× 106 cells/mL. Bakery yeast was provided twice day at a rate of 0.5g/million rotifer. Results showed that feeding with the newly isolated Nanochloris sp. could help improve lipid content of cultured rotifers. However, this species alone can not produce high quality rotifers. It should be used in combination with bakery yeast or Nannochloropsisoculata.Further research is required to evaluate the use of Nanochloris sp. in larviculture of penaeid shrimps as a direct livefood. Key words: Nanochloris sp., Nannochloropsisoculata, rotifer culture, protein, lipid.