While the fish gut microbiome composition is important to fish health, studies of the gut microbiome of fish lag behind those of terrestrial vertebrates. Whether the microbial communities in an aquatic habitat affect the gut microbiomes of resident fish is unclear. This study investigates and compares the composition of bacterial communities in the gut of crucian carp and humpback and in the water of their habitat using high-throughput sequencing of two hypervariable regions (V3 and V4) of the 16S rRNA gene. We identified 2058 operational taxonomic units (OTUs) in the humpback, 2551 OTUs in crucian carp, and 1760 OTUs in their habitat water. 218 OTUs were common to all three bacterial communities. Linear discriminant analysis revealed multiple species that differed significantly in abundance between the communities. This study aims to improve our understanding of the influence of the aquatic habitat on fish–microbe relationships.

虽然鱼肠道微生物组的组成对鱼类健康很重要，但对鱼肠道微生物组的研究却落后于陆生脊椎动物。目前尚不清楚水生生境中的微生物群落是否影响常驻鱼类的肠道微生物组。这项研究使用16S rRNA基因的两个高变区（V3和V4）进行高通量测序，研究并比较了the鱼和座头鲸肠道内以及其栖息地水中的细菌群落组成。我们在座头鲸中确定了2058个操作生物分类单位（OTU），在carp鱼中确定了2551个OTU，在栖息地水中确定了1760个OTU。这三个细菌群落共有218个OTU。线性判别分析揭示了多个物种，其群落之间的丰度差异很大。