Fish gut-associated bacterial communities in a tropical lagoon (Aghien lagoon, Ivory Coast)

Abstract

Aghien lagoon (Ivory Coast) is a eutrophic freshwater lagoon that harbors high biomasses of phytoplankton. Despite Increasing interest in fish gut microbiomes diversity and functions, little data is currently available regarding wild species from tropical west African lakes. Here, gut-associated bacterial communities are investigated in four fish species that are consumed by locale populations, namely the Cichlidae Hemichromis fasciatus, Tilapia guineensis and Sarotherodon melanotheron, and the Claroteidae Chrysichthys nigrodigitatus. Species-related differences are identified, that can be attributed to host phylogeny and diet. Important variations throughout the year are observed in T. guineensis and C. nigrodigitatus. This result emphasized the importance of time-series sampling and comparison with environmental variables even in tropical regions, that are not often conducted in wild populations. Effects of environmental factors (anthropogenic or not) on the microbiota and potential outcomes for fish health and populations sustainability need to be further explored. Interestingly, fish appear as major reservoirs of bacterial diversity, suggesting that they could contribute to the overall stability and resilience of bacterial communities present in the Aghien lagoon.

The effect of dietary fish oil replacement by microalgae on the gilthead sea bream midgut bacterial microbiota

“…It includes some species of pathogenic micro-organisms for humans ( Mycobacterium tuberculosis, Mycobacterium leprae ) but also several species that inhabit a diverse range of environments including water bodies, soil, and metalworking fluids (Gupta, Lo & Son 2018). Mycobacterium genus has also been found in the gut of freshwater species (Gallet et al 2022). The closest relative, M. aurum has never been reported as a pathogen, but its possible functions in the gut remain unknown.…”