Consistent host bacterial colonization pattern over shrimp life stage. shrimp gut metagenome

Intestinal microbes and water bodies play a key role in maintaining the health of Penaeus Monodon. Thereby, the quality and stability of rearing environment are highly desirable during intensive shrimp cultivation. we understand that water bodies and intestinal microbes are constantly changing at different stages of shrimp development. To date, however, we just pay attention to the changes in a certain pond, and we don't know if it is universal or representative. Consequently, we collected water samples and shrimp samples from different ponds in XiangShan and Zhan Qi for comparison. We found that there are many factors that affect the intestinal microbes of Penaeus at different stages of development. For instance , water temperature, PH and Dissolved oxygen.In fact, there is increasing evidence that shrimp intestinal bacterial compositions are substantially distinct in different growth stages. It has been reported that the community of the larval intestine is more similar to the surrounding environment than the intestinal community of an adult shrimp;this difference suggests that the empty niches of the larval intestine are subject to stochastic colonization by dispersed microorganisms from ambient water.Consequently, there are substantial variations in the composition of the microbiota among cohabiting larvae.This pattern may partially explain the different susceptibilities to gut infections or probiotic therapies in larvae populations.Therefore, it appears that stochastic processes determine the intestinal assemblages of larvae. Consistently, studies have shown that the relative importance of deterministic processes increases over development stages,suggesting that the colonization of allochthonous probiotics tends to be hampered as hosts mature.

肠道微生物与水体在维持斑节对虾（Penaeus Monodon）的健康过程中发挥关键作用。因此，在斑节对虾集约化养殖过程中，养殖环境的质量与稳定性至关重要。我们已知，在斑节对虾的不同发育阶段，其肠道微生物与养殖水体均处于动态变化之中。然而迄今为止，相关研究多仅关注单一养殖池塘内的微生物变化，尚不清楚该变化是否具有普适性与代表性。为此，本研究采集了象山与湛岐地区多个养殖池塘的水体与虾体样本开展对比分析。研究发现，在斑节对虾的不同发育阶段，诸多因素会对其肠道微生物群落构成影响，例如水温、pH值与溶解氧。事实上，越来越多的研究证据表明，斑节对虾肠道细菌群落组成在不同生长阶段存在显著差异。已有研究显示，斑节对虾幼虾肠道微生物群落与周边养殖水体的相似度，远高于成虾肠道微生物群落与水体的相似度；这一差异表明，幼虾肠道的空白生态位易受外界水体中弥散传播的微生物随机定殖。因此，同池饲养的幼虾之间，其肠道微生物群落组成存在显著差异。该现象可在一定程度上解释幼虾种群对肠道感染或益生菌疗法的易感程度存在差异的原因。由此可见，随机过程决定了幼虾肠道的微生物群落组成。与此一致的是，已有研究表明，确定性过程的相对重要性会随着斑节对虾的发育阶段推进而提升，这意味着随着宿主成熟，外源益生菌的定殖往往会受到阻碍。