Investigating the gut microbiomes of aquatic benthic macroinverterbrates in the Saint John river (New Brunswick, Canada)

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University of New Brunswick


Aquatic invertebrates are key members of aquatic food webs; however, little is known about their gut microbiomes. Understanding how environment, taxonomy, dietary habits, and time alter gut bacteria is important in addressing current gaps in microbiome research. The objectives of this study were to characterize the gut microbiomes of aquatic invertebrates and to assess whether the composition of gut bacteria differs temporally and across taxa with different habitats and feeding habits. Invertebrates from 16 orders were collected from 8 sites within a 20 km reach of the Saint John River (New Brunswick, Canada) in fall 2016 and 2017, with these individuals containing nearly 20,000 operational taxonomic units. Gut microbiomes of invertebrates differed significantly among invertebrate taxa and temporally; however, few significant within-taxa differences were found among habitat types and no significant differences were observed among functional feeding groups. This study is the first to describe the gut microbiomes of aquatic invertebrates in the Saint John River. This information establishes a baseline of natural variability and diversity of aquatic invertebrate gut microbiomes, providing a foundation for future work.