| Microbiota dynamics of the clarium catfish during the first months of life |
| Paper ID : 1071-ICIAQUA |
| Authors |
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Evgeniya Prazdnova *1, Maksim Kulikov1, Maria Mazanko2 11- Southern Federal university; 2- Don State Technical university 21- Southern Federal university; 2- Don State Technical university |
| Abstract |
| Purpose: The need to improve disease resistance and growth performance has stimulated the development and application of probiotics in aquaculture. However, effective use of probiotics requires information on the gut microbiome of fish. The aim of this work is to create a model of the microbiota of the clarium catfish during the first months of life, since during this period the fish is most vulnerable to stress and pathogens. Method: The metagenomic model was built on the sequencing data of 16S rRNA V3-V4 regions. Data were processed via QIIME v.1.9.1, Kraken2 v2.0.8-beta, and Bracken v2.5.0 software. Results: In contrast to adult freshwater fish, where the main phylum of the microbiota is Fusobacteriota with the main representative Cetobacterium somerae, in fry the phylum Proteobacteria prevailed during the first days of active feeding, including Betaproteobacteria which is not characteriscic for adult fish, and potentially pathogenic Flavobacterium. After switching from live feed to commercial starter feed, the microbiota of the fry changed. Flavobacterium disappeared and Cetobacterium somerae decreased significantly. The relative abundance of Betaproteobacteria decreased, as well as number of vibrios. The relative number of Firmicutes and Alphaproteobacteria increased. After 2 months, the relative number of Firmicutes decreased and the number of Proteobacteria increased again, especially Betaproteobacteria. Conclusions: The structure of the intestinal contents of fry is dominated by Proteobacteria and Firmicutes, many of which are opportunistic strains. Therefore, it is important to introduce probiotics into the food of fry during the early stages of growth to shift the microbial balance towards beneficial bacterial species and reduce fry mortality during the first months of life. |
| Keywords |
| Clarias catfish, Clarias gariepinus, microbiota, metagenome, aquaculture. |
| Status: Abstract Accepted (Oral Presentation) |