Does the Composition of the Gut Bacteriome Change during the Growth of Tuna?

Abstract

In recent years, a growing number of studies sought to examine the composition and the determinants of the gut microflora in marine animals, including fish. For tropical tuna, which are among the most consumed fish worldwide, there is scarce information on their enteric bacterial communities and how they evolve during fish growth. In this study, we used metabarcoding of the 16S rDNA gene to (1) describe the diversity and composition of the gut bacteriome in the three most fished tuna species (skipjack, yellowfin and bigeye), and (2) to examine its intra-specific variability from juveniles to larger adults. Although there was a remarkable convergence of taxonomic richness and bacterial composition between yellowfin and bigeyes tuna, the gut bacteriome of skipjack tuna was distinct from the other two species. Throughout fish growth, the enteric bacteriome of yellowfin and bigeyes also showed significant modifications, while that of skipjack tuna remained relatively homogeneous. Finally, our results suggest that the gut bacteriome of marine fish may not always be subject to structural modifications during their growth, especially in species that maintain a steady feeding behavior during their lifetime.

Comparative Study of Intestinal Microbiota Composition of Six Edible Fish Species

“…When making pairwise comparisons of big and small fish of the same species, only two out of the four sampled small species (common carp and hybrid tilapia) showed significant differences between the microbiota composition. Gadoin et al (2021) found that only two of three species of tuna fish (yellowfin and bigeye) from the eastern Atlantic Ocean had significant differences between the microbiota composition of small and big fish within the species, while the third species (skipjack) did not. They explained that the reason for this pattern was likely steady feeding behavior of the third species during its lifetime as opposed to differential, age-related feeding habit in the other two species ( Gadoin et al, 2021 ).…”

“…The fish gut microbial community changes with the host’s developmental stage ( Giatsis et al, 2014 ). Fish size may be related to gut microbiota composition within the same species ( Gadoin et al, 2021 ). The fish’s intestine is able to harbor 10 7 to 10 11 bacteria for each gram of intestinal content ( Navarrete et al, 2012 ).…”

Preliminary study of shark microbiota at a unique mix-species shark aggregation site, in the Eastern Mediterranean Sea

“…Moreover, this individual factor is affected by the gender of the organism (Cabal et al, 2018) and its genetic material (Opstal and Bordenstein, 2015). In addition, the physiological condition of the organism, such as disease (Cho and Blaser, 2012), pregnancy (Neuman and Koren, 2017), metabolic state (Bang et al, 2018) and developmental phase (Gadoin et al, 2021) may affect and shape the composition of the microbiota. Interestingly, differences in the cohort's behavior have been reported in previous studies to affect the microbiome (Archie and Tung, 2015;Vuong et al, 2017).…”

“…The host offers favorable niches for microbes which, in turn, provide services to its hosts. These microbial niches change in their conditions, function and availability as the host organism develops and switches from one life-phase to the next (Williams et al, 2018;Gadoin et al, 2021). The diverse microbial communities can provide the host with optimal functionality and flexibility to changing environmental conditions (Zilber-Rosenberg and Rosenberg, 2008).…”

“…On the other hand, a change in microbiota composition (due to physiological or environmental changes) can manifest as dysbiosis and may negatively affect the host (Rosenfeld, 2017). Many studies on marine organisms have examined the variation in microbiota in relation to its host species (Lima et al, 2012;Chiarello et al, 2017) life stage (Gadoin et al, 2021), health (Sweet and Bulling, 2017;West et al, 2019), ecology and environmental monitoring (Buck-Wiese et al, 2016;Glasl et al, 2019;Leray et al, 2021). These studies emphasize the importance of the microbiome, which can provide essential information on both the host and its environment.…”