Figuerola Blanca, Linares Cristina, Aparicio-Estalella Claudia, López-Sendino Paula, Garrabou Joaquim, Del Campo Javier
Departament de Biologia Marina i Oceanografia, Institut de Ciències del Mar (ICM-CSIC), Barcelona, Spain.
Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Facultat de Biologia, Universitat de Barcelona (UB), Barcelona, Spain.
Environ Microbiol Rep. 2025 Oct;17(5):e70185. doi: 10.1111/1758-2229.70185.
Marine heatwaves are intensifying due to global warming and increasingly drive mass mortality events in shallow benthic ecosystems. Marine invertebrates host diverse microbial communities that contribute to their health and resilience, yet microbiome responses under thermal stress remain poorly characterised across most taxa. Here, we characterise the microbiome composition in colonies of the common Mediterranean bryozoan Myriapora truncata at two depths (13 and 17 m) following the extreme 2022 marine heatwave. Despite no visible necrosis, microbial communities at both depths exhibited shifts indicative of thermal stress, including the reduced presence of potential core microbial members. Colonies from the shallower, warmer depth showed higher alpha diversity and reduced abundance of key functional genera compared to deeper colonies, suggesting early dysbiosis. These results highlight that M. truncata-though visually unaffected-undergoes sublethal microbiome alterations under thermal stress. This study provides the first characterisation of a bryozoan microbiome after a marine heatwave and highlights the potential of host-associated microbial communities as early bioindicators of invertebrate stress in a warming ocean.
由于全球变暖，海洋热浪正在加剧，并越来越多地导致浅海海底生态系统中的大规模死亡事件。海洋无脊椎动物拥有多样的微生物群落，这些群落有助于它们的健康和恢复力，然而，在热应激下，大多数分类群的微生物组反应仍知之甚少。在这里，我们描述了在经历了2022年极端海洋热浪后，常见的地中海苔藓虫截形多孔苔藓虫在两个深度（13米和17米）的菌落中的微生物组组成。尽管没有明显的坏死现象，但两个深度的微生物群落都表现出表明热应激的变化，包括潜在核心微生物成员的减少。与较深的菌落相比，来自较浅、较温暖深度的菌落显示出更高的α多样性和关键功能属的丰度降低，表明早期生态失调。这些结果突出表明，截形多孔苔藓虫虽然在视觉上未受影响，但在热应激下会发生亚致死性微生物组改变。这项研究首次描述了海洋热浪后苔藓虫微生物组的特征，并强调了宿主相关微生物群落作为变暖海洋中无脊椎动物应激早期生物指标的潜力。
