Effect of Probiotic Used on Phytoplankton Community Structure in White Shrimp (Litopenaeus vannamei) Pond

Abstract

Probiotic use is one major approach to eliminating waste accumulation in shrimp farming. This study investigated the effects of probiotic use on the abundance and diversity of phytoplankton at the farm level. The results revealed 4 divisions for 12 genera of phytoplankton, consisting of Cyanophyta (Oscillatoria sp., Pseudanabaena sp., Planktolyngbya sp. and Merismopedia sp.), Chlorophyta (Scenedesmus sp. and Monorapidium sp.), Bacillariophyceae (Nitzschia sp., Pleurosigma/Gyrosigma sp. and Navicula sp.) and Pyrrophyta (Protoperidinium sp., Ceratium sp. and Prorocentrum sp.). Pyrrophyta exhibited the highest density, followed by Cyanophyta, Bacillariophyta and Chlorophyta. The cell density of 4 divisions was high at the start rearing e.g., Pyrrophyta 47,991 cells/L (85%), Cyanophyta 3,141 cells/L (5%), Bacillariophyta 3,530 cells/L (6%), and Chlorophyta 1,965 cells/L (3%). However, the density drastically changed at the end of the study in 19 days, especially in Pyrrophyta, for which cell density dropped to 4,705 cells/L (48%). The density of Cyanophyta increased towards day 7 and decreased at the end of the study (2,126 cells/L, 22%). The density of Bacillariophyceae and Chlorophyta were reduced in the initial cultivation from day 1 to day 10 but increased again before the end of the study for 1,176 cells/L (12%) and 1,698 cells/L (18%). The research indicates that adding probiotics to shrimp ponds can affect the abundance of the phytoplankton community. Probiotics can reduce an abundance of Pyrrophyta and Cyanophyta (biotoxin producing group.), while they show a trend to increase an abundance of Chlorophyta and Bacillariophyta.