Sidón-Ceseña Karla, Martínez-Mercado Miguel Angel, Chong-Robles Jennyfers, Ortega-Saad Yamne, Camacho-Ibar Victor Froylán, Linacre Lorena, Lago-Lestón Asunción
Posgrado de Ciencias de la Vida, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, 22860, México.
Departamento de Biotecnología Marina, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, 22860, México.
FEMS Microbiol Ecol. 2025 Jan 28;101(2). doi: 10.1093/femsec/fiaf009.
Marine protists are key components of biogeochemical cycles and microbial food webs, which respond quickly to environmental factors. In the Gulf of Mexico (GoM), the Loop Current intensifies in summer and supplies the gulf with warm and oligotrophic waters. However, the cyclonic eddies within the GoM create favorable conditions for biological productivity by bringing nutrient-rich water to the subsurface layer. In this study, we investigated the response of the protist community to the regional physicochemical conditions, its spatial and temporal variability, the influence of mesoscale structures, and its ecological roles in the mixed layer (ML) and deep chlorophyll maximum (DCM). This is the first study to conduct a V9-18S rRNA gene survey for this community in the Mexican Exclusive Economic Zone of the GoM. The regional distribution, temporal changes, and mesoscale structures significantly affected the structure of the protist community in the ML. In contrast, only mesoscale structures significantly affected the protist community in the DCM. Different protist assemblages were also present between the ML and DCM, with the Alveolata representing ∼60% of the community in both layers, followed by haptophytes and MAST (Marine Stramenopiles) in the ML; pelagophytes and radiolarians were the more prevalent taxa in the DCM. Finally, co-occurrence analyses revealed that competition, parasitism, and predation were the potential interactions shaping these communities at both depths.
海洋原生生物是生物地球化学循环和微生物食物网的关键组成部分，它们对环境因素反应迅速。在墨西哥湾，环流在夏季增强，为海湾提供温暖且贫营养的海水。然而，墨西哥湾内的气旋涡通过将富含营养的水带到次表层，为生物生产力创造了有利条件。在本研究中，我们调查了原生生物群落对区域物理化学条件的响应、其时空变异性、中尺度结构的影响以及它在混合层（ML）和深层叶绿素最大值层（DCM）中的生态作用。这是首次在墨西哥湾墨西哥专属经济区内对该群落进行V9 - 18S rRNA基因调查。区域分布、时间变化和中尺度结构显著影响了混合层中原生生物群落的结构。相比之下，只有中尺度结构显著影响了深层叶绿素最大值层中的原生生物群落。混合层和深层叶绿素最大值层之间也存在不同的原生生物组合，在这两层中，囊泡虫约占群落的60%，其次是混合层中的定鞭藻和海洋不等鞭毛藻；硅藻和放射虫是深层叶绿素最大值层中更普遍的类群。最后，共现分析表明，竞争、寄生和捕食是在两个深度塑造这些群落的潜在相互作用。
