Fujian Key Laboratory on Conservation and Sustainable Utilization of Marine Biodiversity, Fuzhou Institute of Oceanography, College of Geography and Oceanography, Minjiang University, Fuzhou, 350108, China.
Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, China.
Harmful Algae. 2024 Sep;138:102685. doi: 10.1016/j.hal.2024.102685. Epub 2024 Jul 7.
The significant threat posed by the ichthyotoxic dinoflagellate Karenia mikimotoi to coastal aquaculture, resulting in substantial economic losses, underscores the need for control and mitigation strategies. Bio-mitigation of algal blooms through grazers presents advantages in sustainability compared to methods relying on chemical or physical procedures. This study explored the inhibitory effect of nine Euplotes spp. (Alveolata, Ciliophora) isolates on simulated blooms, with E. balteatus W413 displaying removal capacity for K. mikimotoi and robust growth in co-cultivation. The unique size plasticity in W413 revealed an efficient predation strategy, as an increase in cellular size enables it to shift prey from bacteria to algal cells. The enlarged cell volume facilitates W413 to accommodate more algal cells, bestowing it with a high ingestion rate and removal capacity upon K. mikimotoi. Furthermore, W413 exhibited considerable inhibition towards co-occurring bloom species, specifically Prorocentrum shikokuense and Karenia spp., implying its potential to mitigate mixed-species blooms. The study enhances our understanding of the prey selectivity of Euplotes species and proposes E. balteatus as a potential bio-mitigation candidate for K. mikimotoi blooms, emphasizing the significance of micro-grazers in marine ecosystems.
赤潮甲藻米氏凯伦藻对沿海养殖业构成严重威胁，导致巨大经济损失，这凸显了需要采取控制和缓解策略。与依赖化学或物理方法的方法相比，通过食藻动物进行生物缓解在可持续性方面具有优势。本研究探讨了九种真游仆虫（纤毛门，缘毛目）分离物对模拟赤潮的抑制作用，其中 E. balteatus W413 对米氏凯伦藻具有去除能力，并在共培养中表现出强劲的生长。W413 的独特尺寸可塑性揭示了一种有效的捕食策略，因为细胞尺寸的增加使其能够将猎物从细菌转移到藻类细胞。增大的细胞体积使 W413 能够容纳更多的藻类细胞，从而使其对米氏凯伦藻具有高吞噬率和去除能力。此外，W413 对共存的赤潮物种，特别是 Prorocentrum shikokuense 和凯伦藻属物种，表现出相当大的抑制作用，这意味着它有可能缓解混合物种赤潮。该研究增进了我们对真游仆虫物种猎物选择性的理解，并提出 E. balteatus 作为米氏凯伦藻赤潮的潜在生物缓解候选物，强调了微型食藻动物在海洋生态系统中的重要性。
