Feeding Ecology of Mixotrophic Bloom-Forming Dinoflagellates

本研究旨在探讨两种赤潮甲藻Gymatinium sanguineum和Ceratium furca的摄食生态。实验室和野外研究将检验以下假设：兼养甲藻：（1）主要是光合生物，当营养和/或光照环境不佳时，它们变成食腐生物;（2）利用各种微型和微型浮游生物猎物，但可以表现出摄食偏好;（3）通过摄食获得足够的营养益处，以促进增强的光合作用和生长;和（4）在一个昼夜循环中进食，在白天增加对猎物的摄入。混合营养甲藻似乎有相对缓慢的摄食速率，但他们的绝对数量在水华条件下表明其潜在的重要性微生物食物网的结构和功能。如果没有更好地了解混合营养甲藻的摄食行为，它们对微生物食物网动力学和赤潮生态学的意义将仍然是猜测。***

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. ***