Photoperiod influence on growth performance and intestinal microbiota in Chinese grass shrimp (Palaemonetes sinensis)

Understanding the influence of photoperiod on aquatic organisms is crucial for optimizing aquaculture practices and enhancing production. This study aims to explore the effects of photoperiod on the growth and microbial aspects of Palaemonetes sinensis. Shrimp were exposed to natural conditions (10 L:14D), continuous light (24 L:0D), and continuous darkness (0 L:24D). The dark group showing the highest survival rate and the natural light group exhibiting the highest weight gain. High-throughput sequencing of the V3-V4 region of the 16S rRNA gene revealed differences in gut microbial composition among the groups. Analysis showed that the light group had the highest microbial richness and diversity. Beta diversity analysis indicated structural differences in microbial communities, with the light group showing the most distinct composition. At the phylum level, Proteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes were the predominant phyla across all groups, with Actinobacteria significantly higher in the dark group. At the genus level, Aeromonas was dominant in both the light and dark groups, while Plesiomonas was dominant in the light group. Our findings provide insights into the effects of photoperiod on shrimp growth, survival, and gut microorganisms, offering guidance for production practices.