Effect of salinity variation on intestinal microbiota of the Indian white shrimp Penaeus indicus H. Milne Edwards, 1837

The effects of salinity adaptation on gut microbiota of juvenile Indian white shrimp, Penaeus indicus H. Milne Edwards, 1837 was analysed in this experiment. Intestines of shrimps adapted to two different salinities were examined using 16S rRNA amplicon sequencing. At all salinity levels, the dominant phyla recorded were Proteobacteria followed by Bacteroidota and Fusobacteriota. However, as the salinity decreased, abundance of Proteobacteria increased while richness of Bacteroidota and Fusobacteriota decreased significantly. At genus level, salinity reduction increased the abundance of Vibrio and Photobacterium; while it decreased the abundance of Spongiimonas and Hypnocyclicus. The survival of animals in both the groups was not affected but the weight gain was less in low saline group (5 ppt). The results confirm the influence of salinity in rearing water on the intestinal microbiota of shrimp. Keywords: Aquaculture, Bacteroidota, Fusobacteriota, Hypnocyclicus, Proteobacteria, Salinity, Spongiimonas