Abstract:Investigations were conducted on the microalgae community in high-level prawn ponds of Litopenaeus annamei. A total of 26 microalgae species were identified during the period of investigation. Of these, 10 species were Chlorophyta, 7 were Pyrrophyta, 4 were Euglenophyta, 2 each were Bacillariophyta and Cyanophyta, and 1 was Chrysophyceae. In high-level prawn ponds, Chlorella pyrenoidosa and Oscillatoria chlorine were the dominant species in the later phases of the culture period, contributing more than 90% of the total microalgae. The number of microalgae was in the range of 5.13×108~4.01×109 ind/L, biomass 42.92~181.73 mg/L. The averages of Shannon-Wiener index and biomass diversity index were 1.01~1.30 and 1.83~2.27, respectively. The three dominant groups of phytoplankton (Cyanophyta, Chlorophyta and Bacillariophyta) consisted of phytoplankton community structure in the final culture phases.
