In this study, we aimed to understand how the diversity and assembly mechanisms of microbial communities from different body habitats (gill, skin, stomach and hindgut) change with development of Siganus fuscescen. As one excellent natural marine source of nutritional lipids, S. fuscescens are truly herbivorous and concurrently omnivorous fish, and commercially important marine teleost fish, which is widespread at coastal areas. They also can bio-transform toxic arsenic to detoxify inorganic arsenic, making it safer for humans to eat.. The metacommunity of Siganus fuscescens associated microbial communities

Although mounting evidence suggested that body habitat and host development can significantly affect the diversity and composition of the microbiome in animals, the corresponding metacommunity underlying mechanism in aquatic animals are unclear. The Siganus fuscescen, which widely distributed in shallow coastal areas, is one of the most important consumers of macroalgae. To obtain an integrated view of ecology of S. fuscescens-associated microbes and how they divers in different habitats and times, we investigated bacteria from four body habitats (skin, gill, stomach and hindgut) at three sampled times (June, August and October). The 108 individuals of wild S. fuscescens with different sizes were investigated using high throughput sequencing. We found that body habitat showed stronger effects than that of sampling time on the microbial community composition. Moreover, the variation between hindgut and the other habitats (skin, gill and stomach) was significant. Further quantification of the ecological processes governing the host-associated microbiome assembly indicated that the heterogeneous selection was major process shaping the microbiome in S. fuscescens. In contrast, the stochastic process seems to be much more for the assembly of free-living water microbiome. These findings suggest that the S. fuscescens-associated microbiome alterations might arise from habitat spatial separated and limiting dispersal, which has implications for S. fuscescens special functional organ and help to development a strategy aimed to build a model for ecological healthy breeding.