Abstract

A deteriorated water quality is closely associated with disease outbreaks in aquaculture, where microorganisms play indispensable roles in improving water quality and aquatic animals’ health. Mangrove is known to be a natural water quality filter and microbiological buffer of pathogen and prebiotics. However, it is unclear how and to what extent Rhizophora apiculata plantation is of benefits to the gut microbiota and growth over mud crab (Scylla paramamosain) aging. To address these concerns, we explored the bacterial communities in mud crab gut and rearing water at 45, 114, and 132 days after incubation, roughly corresponding to juvenile, pre-adult, and adult stages of mud crab. Results showed that 1-year R. apiculata plantation slightly increased the body weight of mud crab and improved water quality to a certain extent. Both bacterioplankton and gut bacterial communities were highly temporal dynamic, while the two communities were significantly distinct (ANOSIM r = 0.90, P = 0.0001). Relative abundances of dominant taxa in water and gut significantly varied between the plantation and the control conditions over mud crab aging. R. apiculata plantation promoted the stability of gut microbiota, as evidenced by more diverse core species. Furthermore, R. apiculata plantation led to the dominance of Verrucomicrobiae species in water and probiotic Bacteroidetes and Lactobacillales taxa in gut. A structural equation model revealed that water variables directly constrained gut microbiota, which in turn affected the body weight of mud crab (r = 0.52, P < 0.001). In addition, functional pathways facilitating immunity and lipid metabolism significantly increased in mud crab gut under the plantation, while those involved in infectious diseases exhibited the opposing trend. These findings greatly expand our understanding of the R. apiculata plantation effects on water quality, gut microbiota, and growth feature of mud crab. Overall, R. apiculata plantation is beneficial for mud crab growth and health.

Key Points

• A short-term R. apiculata plantation could potentially improve water quality.

• Bacterioplankton is more sensitive than mud crab gut microbiota in response to R. apiculata plantation.

• R. apiculata plantation enhances mud crab resistance against pathogen invasion.

• R. apiculata plantation alters mud crab gut microbiota, which in turn promotes their body weight.

中文翻译：

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尖峰根茎人工林改善泥蟹水质，生长和健康的效果。

摘要

水质恶化与水产养殖疾病的暴发密切相关，微生物在改善水质和水生动物健康方面起着不可或缺的作用。红树林是一种天然的水质过滤器，是病原体和益生元的微生物缓冲剂。但是，目前尚不清楚人工根瘤菌人工林如何以及在多大程度上对肠道菌群和泥蟹（Scyla paramamosain）老化的生长有利。为了解决这些问题，我们在孵化后第45、114和132天探索了蟹蟹肠和饲养水中的细菌群落，大致对应于蟹蟹的幼年，成年前和成年期。结果表明，一年的尖头鸦片人工林略有增加泥蟹的体重，并在一定程度上改善了水质。浮游细菌和肠道细菌群落都具有高度的时间动态性，而这两个群落则明显不同（ANOSIM r = 0.90，P = 0.0001）。在人工蟹和蟹蟹老化的控制条件之间，水和肠中优势类群的相对丰度差异很大。Apiculata人工林促进了肠道菌群的稳定性，这一点已由多种核心物种证明。此外，R.红树种植导致的主导地位Verrucomicrobiae种水和益生菌拟杆菌和乳杆菌肠道内的分类单元。一个结构方程模型表明，水变量直接限制了肠道菌群，进而影响了泥蟹的体重（r = 0.52，P <0.001）。此外，人工林下蟹蟹肠道中促进免疫和脂质代谢的功能途径显着增加，而那些与传染病有关的途径则呈现相反的趋势。这些发现极大地扩展了我们对R. apiculata人工林对水质，肠道菌群和泥蟹生长特征的影响的理解。总体而言，R。apiculata人工林有益于泥蟹的生长和健康。

关键点

•短期的R. apiculata种植可以潜在地改善水质。

•响应浮萍人工林，细菌浮游生物比泥蟹肠道菌群更敏感。

• Apiculata人工林可增强泥蟹抵抗病原体入侵的能力。

• Apiculata人工林改变了蟹蟹肠道菌群，进而提高了它们的体重。