Tri-spine horseshoe crabs (HSCs) Tachypleus tridentatus have been facing the threat of population depletion for decades, and the physiology and microbiology of their early life stages are lacking. To explore what directs the change of juvenile T. tridentatus gut microbiota and how gut microbiota change, by using 16S rRNA sequencing of gut samples we detected the intestinal microbiome of juvenile HSCs and compared the impact of initial molting and initial feeding, as well as the effect of environment. Results showed that the predominant phyla in the gut microbial community of juvenile HSCs are Proteobacteria and Bacteroidetes. The richness and diversity of intestinal microbes greatly decreased after initial molting. Microbial-mediated functions predicted by PICRUSt showed that “Signal Transduction”, “Cellular Processes and Signaling”, “Infective Diseases” and “Digestive System” pathways significantly increased in 2nd instars. As for the effect of environment, the connection between living environment and the intestinal microbiome started to manifest after initial molting. Unexpectedly, initial feeding treatment slightly affected the intestinal microbiome of T. tridentatus in the early life stage, whereas the effect of initial molting was significant. The present study provided the first insight into the gut microbiota of T. tridentatus, and the findings led a new sight to explain what guide the change of gut microbiota.

中文翻译：

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初始饲养和蜕皮对 Tachypleus tridentatus 肠道微生物群的影响

三齿鲎 (HSCs) Tachypleus tridentatus 几十年来一直面临种群枯竭的威胁，缺乏其早期生命阶段的生理学和微生物学。为了探索是什么引导了幼鱼 T. tridentatus 肠道微生物群的变化以及肠道微生物群如何变化，通过使用肠道样本的 16S rRNA 测序，我们检测了幼年 HSC 的肠道微生物群，并比较了初始蜕皮和初始喂养的影响，以及环境的影响。结果表明，幼年 HSC 肠道微生物群落中的主要门是 Proteobacteria 和 Bacteroidetes。初次蜕皮后肠道微生物的丰富度和多样性大大降低。PICRUSt 预测的微生物介导的功能表明，“信号转导”、“细胞过程和信号”、“传染病”和“消化系统”通路在二龄显着增加。至于环境的影响，生活环境与肠道微生物组之间的联系在初始蜕皮后开始显现。出乎意料的是，初始饲喂处理对 T. tridentatus 在生命早期阶段的肠道微生物群有轻微影响，而初始蜕皮的影响显着。本研究首次提供了对 T. tridentatus 肠道微生物群的见解，这些发现为解释肠道微生物群变化的指导因素提供了新的视角。初始喂养处理对 T. tridentatus 在生命早期阶段的肠道微生物群有轻微影响，而初始蜕皮的影响显着。本研究首次提供了对 T. tridentatus 肠道微生物群的见解，这些发现为解释肠道微生物群变化的指导因素提供了新的视角。初始喂养处理对 T. tridentatus 在生命早期阶段的肠道微生物群有轻微影响，而初始蜕皮的影响显着。本研究首次提供了对 T. tridentatus 肠道微生物群的见解，这些发现为解释肠道微生物群变化的指导因素提供了新的视角。