Inducible Mixotrophy in the Dinoflagellate Prorocentrum minimum
Inducible Mixotrophy in the Dinoflagellate Prorocentrum minimum
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DOI：
10.1111/jeu.12198
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发表时间：
2015-07-01
影响因子：
2.2
通讯作者：
Johnson, Matthew D.
中科院分区：
文献类型：
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作者：
Johnson, Matthew D.
微小原甲藻是一种浅海甲藻，在河口生态系统中形成季节性水华和赤潮。虽然已知是混合营养的，但以前记录以藻类猎物为食的尝试都产生了较低的放牧率。在这项研究中，测量了氮(-N)和磷(-P)饥饿对磷的生长和摄食率的影响。切萨皮克湾的一株最小原甲藻在静止阶段摄食隐藻猎物，在N或P饥饿时摄食两株文昌鱼，其摄食率高于其他6种隐藻。在所有情况下，-P处理导致最高的放牧量。-P细胞在文昌鱼上的摄食率接近于每个捕食者每天5个猎物的摄食率，而-N细胞的摄食率在每个捕食者每天1个猎物时饱和。在捕食物存在的情况下，-P处理细胞的最大混合营养生长速率(Max)为0.5d(-1)，而-N细胞的最大混合营养生长速率(Max)为0.18d(-1)。对文昌鱼摄食的C、N和P的计算表明，吞噬作用可能是这三种元素的重要来源。虽然P.minum是一种熟练的光生生物，但可诱导的吞噬是这种甲藻的重要营养来源。
Prorocentrum minimum is a neritic dinoflagellate that forms seasonal blooms and red tides in estuarine ecosystems. While known to be mixotrophic, previous attempts to document feeding on algal prey have yielded low grazing rates. In this study, growth and ingestion rates of P. minimum were measured as a function of nitrogen (-N) and phosphorous (-P) starvation. A P. minimum isolate from Chesapeake Bay was found to ingest cryptophyte prey when in stationary phase and when starved of N or P. Prorocentrum minimum ingested two strains of Teleaulax amphioxeia at higher rates than six other cryptophyte species. In all cases -P treatments resulted in the highest grazing. Ingestion rates of -P cells on T. amphioxeia saturated at similar to 5 prey per predator per day, while ingestion by -N cells saturated at 1 prey per predator per day. In the presence of prey, -P treated cells reached a maximum mixotrophic growth rate ((max)) of 0.5d(-1), while -N cells had a (max) of 0.18d(-1). Calculations of ingested C, N, and P due to feeding on T. amphioxeia revealed that phagotrophy can be an important source of all three elements. While P. minimum is a proficient phototroph, inducible phagotrophy is an important nutritional source for this dinoflagellate.