Effects of aging on the skin and gill microbiota of farmed seabass and seabream

Abstract

Background: Important changes in microbial composition related to sexual maturation have been already reported in the gut of several vertebrates including mammals, amphibians and fish. Such changes in fish are linked to reproduction and growth during developmental stages, diet transitions and critical life events. We used amplicon (16S rRNA) high-throughput sequencing to characterize the skin and gill bacterial microbiota of farmed seabass and seabream belonging to three different developmental age groups: early and late juveniles and mature adults. We also assessed the impact of the surrounding estuarine water microbiota in shaping the fish skin and gill microbiota. Results: Microbial diversity, composition and predicted metabolic functions varied across fish maturity stages. Alpha-diversity in the seabass microbiota varied significantly between age groups and was higher in older fish. Conversely, in the seabream, no significant differences were found in alpha-diversity between age groups. Microbial structure varied significantly across age groups; moreover, high structural variation was also observed within groups. Different bacterial metabolic pathways were predicted to be enriched in the microbiota of both species. Finally, we found that the water microbiota was significantly distinct from the fish microbiota across all the studied age groups, although a high percentage of ASVs was shared with the skin and gill microbiotas.Conclusions: We report important microbial differences in composition and potential functionality across different ages of farmed seabass and seabream. These differences may be related to somatic growth and the onset of sexual maturation. Importantly, some of the inferred metabolic pathways could enhance the fish coping mechanisms during stressful conditions. Our results provide new evidence suggesting that growth and sexual maturation have an important role in shaping the microbiota of the fish external mucosae and highlight the importance of considering different life stages in microbiota studies.

Relationships between pond water and tilapia skin microbiomes in aquaculture ponds in Malawi

“…Host genetics is further known to contribute to the inter-individual variation of fish skin communities (Boutin et al, 2014). Additionally, fish age has been seen to influence individual taxa abundances but offers a limited explanation of inter-individual variation at the microbial community level (Rosado et al, 2021). To account for the observed inter-individual variation of fish skin microbiomes we recommend increased fish numbers (6 or more) per treatment/location during sampling campaigns.…”

Impact of early-life rearing history on gut microbiome succession and performance of Nile tilapia

“…The developmental stage of the host was claimed to influence fish microbiota succession during ontogenesis in zebrafish [ 21 – 23 ], Gibel carp [ 24 ], Southern catfish [ 25 ], Atlantic salmon [ 26 ], seabass and seabream [ 27 ]. Temporal shifts in fish gut microbiome were evidenced irrespective of whether diet and environmental conditions were constant [ 25 ] or not [ 22 , 24 ].…”

Fish disease prevention via microbial dysbiosis‐associated biomarkers in aquaculture

“…as part of the core microbiota in the mucosal surfaces of European seabass and seabream. 68,69 The beneficial effects of Rubritalea spp. are most likely associated with the production of carotenoids and squalene production (i.e.…”

“…Other studies have similarly identified Rubritalea spp. as part of the core microbiota in the mucosal surfaces of European seabass and seabream 68,69 . The beneficial effects of Rubritalea spp.…”