Characterization of the gut microbiota in early life stages of pikeperch Sander lucioperca.

This study characterized the gastrointestinal microbiome of nine juvenile farmed pikeperch Sander lucioperca using a metagenomics approach based on bacterial 16S rRNA gene sequencing. Potential changes in the gut microbiota during 2 months of S. lucioperca juvenile life were investigated. Results revealed that gut microbiota was dominated by Proteobacteria (95-92%), while other phyla Firmicutes (1-1·5%) and Actinobacteria (0·9-1·5%) were less abundant. At the family level, fish-gut microbiota were dominated by Enterobacteriaceae, which constituted c. 83% of all DNA sequence reads. Such a situation was present in all of the examined fish except one, which showed a different proportion of particular microbial taxa than the other fish. In this fish, a higher relative abundance (%) of Fusobacteria (21·0%), Bacteroidetes (9·5%) and Firmicutes (7·5%) was observed. There were no significant differences in the gut microbiome structure at different stages of development in the examined fish. This may indicate that Proteobacteria inhabiting the gut microbiota at an early stage of life are a necessary component of the pikeperch microbiome that may support proper nutrition of the fish. The information obtained on the gut microbiome could be useful in determining juvenile S. lucioperca health and improving rearing conditions by welfare monitoring in aquaculture.