Feeding Ecology of Mixotrophic Bloom-Forming Dinoflagellates

Stoecker 9317732本研究将研究两种赤潮甲藻：血裸藻和叉尾藻的摄食生态。实验室和野外研究将检验关于混合营养甲藻的假设：(1)主要是光合作用生物，在营养和/或光环境不佳时变得吞噬；(2)利用各种纳米和微型浮游生物猎物，但可以表现出摄食偏好；(3)通过吞噬获得足够的营养益处，以促进光合作用和生长；(4)以日粮循环为食，猎物摄入量增加。混合营养的甲藻似乎具有相对较慢的摄食速率，但它们在水华条件下的绝对数量表明它们对微生物食物网的结构和功能具有潜在的重要性。如果不能更好地了解混合营养型甲藻的摄食行为，它们对微生物食物网动态和赤潮生态的意义仍将是推测的。***

Stoecker 9317732 This study will examine the feeding ecology of two red-tide dinoflagellates Gymnodinium sanguineum and Ceratium furca. Laboratory and field studies will test the hypotheses that mixotrophic dinoflagellates: (1) are primarily photosynthetic organisms that become phagothrophic when nutrient and/or light environments are suboptimal; (2) exploit a variety of nano- and microplankton prey, but can exhibit feeding preferences; (3) gain sufficient nutritional benefits through phagotrophy to promote enhanced photosynthesis and growth; and (4) feed on a diel cycle with elevated ingestion of prey during the day. Mixotrophic dinoflagellates appear to have relatively slow feeding rates, but their sheer numbers under bloom conditions indicate their potential importance to microbial food-web structure and function. Without a greater understanding of feeding behavior in mixotrophic dinoflagellates, their significance to microbial food web dynamics and red-tide ecology will remain speculation. ***