Mena Catalina, Long Marc, Lorand Ophélie, Malestroit Pascale, Rabiller Emilie, Maguer Jean-François, L'helguen Stéphane, Regaudie De Gioux Aurore
Écologie Pélagique (DYNECO/PELAGOS), Institut Français de Recherche pour l'Exploitation de la Mer, IFREMER, 29280 Plouzané, France.
Centre Oceanogràfic de Balears, Instituto Español de Oceanografía, COB-IEO, CSIC, Moll de Ponent s/n, 07015 Palma (Illes Balears), Spain.
J Plankton Res. 2024 Jul 17;47(1):fbae038. doi: 10.1093/plankt/fbae038. eCollection 2025 Jan-Feb.
Phagotrophy is a key nutritional mode for many bloom-forming dinoflagellates that can supplement their carbon and nutrient requirements. However, the environmental drivers and ecological relevance of phagotrophy in algal blooms are still poorly understood. This study evaluates the effect of light and nutrient availability on the phagotrophic activity of three common bloom-forming dinoflagellates (, and ) using three fluorescently labeled preys: bacteria, and the haptophyte . The three dinoflagellates exhibited distinct responses to light and nutrient availability in terms of growth, cell size, prey ingestion and preference. and showed higher cell-specific ingestion rates on bacteria (0.53 ± 0.13 and 1.64 ± 0.39 prey dinoflagellate h, respectively) under co-limited nutrient and light availability, whereas showed higher ingestion on (0.93 ± 0.22 prey dinoflagellate h) under low-light availability alone. However, the three dinoflagellates exhibited the highest carbon and nitrogen-specific ingestion rates when feeding on the larger prey . Our findings indicate that phagotrophy could be of advantage in short periods of light or nutrient limitation and may play different roles during the development of blooms, likely influencing the energy transfer through the food web.
吞噬营养是许多形成水华的甲藻的一种关键营养模式，这些甲藻可以补充自身的碳和营养需求。然而，水华中吞噬营养的环境驱动因素和生态相关性仍知之甚少。本研究使用三种荧光标记的猎物（细菌、 和金藻 ）评估了光照和营养可利用性对三种常见的形成水华的甲藻（ 、 和 ）吞噬营养活性的影响。这三种甲藻在生长、细胞大小、猎物摄取和偏好方面对光照和营养可利用性表现出不同的反应。在营养和光照共同受限的情况下， 和 对细菌表现出更高的细胞特异性摄取率（分别为0.53±0.13和1.64±0.39个猎物甲藻/小时），而 在仅低光照条件下对 表现出更高的摄取率（0.93±0.22个猎物甲藻/小时）。然而，这三种甲藻在以较大的猎物 为食时表现出最高的碳和氮特异性摄取率。我们的研究结果表明，吞噬营养在短期光照或营养限制期间可能具有优势，并且在水华发展过程中可能发挥不同作用，可能影响通过食物网的能量传递。
