Barak Noga, Brekhman Vera, Aharonovich Dikla, Lotan Tamar, Sher Daniel
Department of Marine Biology, The Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, 3103301, Israel.
Environ Microbiome. 2025 May 9;20(1):49. doi: 10.1186/s40793-025-00714-5.
Jellyfish blooms have significant ecological and economic impacts, yet the microbial communities associated with these blooms remain poorly understood, despite their potential influence on host fitness and microbial communities in the surrounding water. In this study, we explored temporal and tissue-specific variations in the microbiota of Rhopilema nomadica, the dominant jellyfish species in the Eastern Mediterranean Sea, across winter and summer blooms. During late summer blooms, microbial richness declined, coinciding with an increase in Endozoicomonas and unclassified Rickettsiales, while Tenacibaculum predominantly characterized winter blooms. Tissue-specific analyses revealed bacterial groups that were more consistently associated with different jellyfish tissues (e.g., Bacteroides in the bell and Simkaniaceae in the gonads), suggesting different microbial niches within the host. Furthermore, some key bacteria associated with R. nomadica, including Endozoicomonas, unclassified Rickettsiales, and Bacteroides were detected in the surrounding bloom water but absent from remote seawater, suggesting potential localized transmission dynamics between jellyfish and their immediate marine environment. Finally, a comparative analysis with nine additional jellyfish species identified recurring microbial taxa, including Endozoicomonas, Mycoplasma, and Spiroplasma, though no universal core microbiota was observed. This study represents the first exploration of microbial dynamics within R. nomadica blooms and the most comprehensive analysis of jellyfish-associated microbiomes across bloom stages and tissues to date. Our findings reveal complex relationships between jellyfish species, bloom progression, their microbial communities, and the surrounding seawater.
水母大量繁殖具有重大的生态和经济影响，然而，尽管与这些水母大量繁殖相关的微生物群落可能对宿主健康以及周围水体中的微生物群落产生影响，但人们对它们的了解仍然很少。在本研究中，我们探究了东地中海占主导地位的水母物种——游水母（Rhopilema nomadica）在冬季和夏季大量繁殖期间微生物群的时间和组织特异性变化。在夏末水母大量繁殖期间，微生物丰富度下降，同时内共生单胞菌属（Endozoicomonas）和未分类的立克次氏体目（Rickettsiales）数量增加，而黄杆菌属（Tenacibaculum）在冬季水母大量繁殖中占主导地位。组织特异性分析揭示了与不同水母组织更一致相关的细菌类群（例如，伞部的拟杆菌属（Bacteroides）和性腺中的西姆卡尼亚科（Simkaniaceae）），这表明宿主体内存在不同的微生物生态位。此外，在周围水母大量繁殖的水体中检测到了一些与游水母相关的关键细菌，包括内共生单胞菌属、未分类的立克次氏体目和拟杆菌属，但在偏远海水中未检测到，这表明水母与其直接海洋环境之间可能存在局部传播动态。最后，与另外九种水母物种的比较分析确定了反复出现的微生物分类群，包括内共生单胞菌属、支原体属（Mycoplasma）和螺原体属（Spiroplasma），尽管未观察到普遍的核心微生物群。本研究首次探索了游水母大量繁殖期间的微生物动态，也是迄今为止对水母整个繁殖阶段和组织相关微生物组最全面的分析。我们的研究结果揭示了水母物种、繁殖进程、它们的微生物群落以及周围海水之间的复杂关系。
