Collaborative Research: Reproductive Periodicity in Planktonic Sarcodines: Implications for Temporal Variability in Abundance and Flux

[9314533] Caron共生浮游生物梭鱼（棘虫、放射虫和有孔虫）是海洋群落表层水中最显著的微型/大型浮游动物类群之一。由于它们在这些环境中的能量流动、营养循环和垂直通量中的重要性，它们也是研究最少的物种之一。浮游沙丁鱼在海洋浮游生物群落（通过其胞内共生藻类）的有机物生产中起着重要作用。此外，由于它们的大尺寸（因此它们潜在的快速下沉速度），它们在从混合层流出的物质通量中也发挥着比它们对浮游生物生物量的总体贡献所预测的更大的作用。以前的研究表明，表面生产力和从混合层流出的沙丁鱼碱物质的通量具有很大的可变性，这可能与某些共生浮游沙丁鱼物种的繁殖周期或导致种群快速增长的偶发性事件有关。该项目将检验这一假设，并确定这些周期性在多大程度上控制了浮游沙丁鱼对百慕大附近少营养化大西洋表层初级生产的重要性的时间变化，以及它们在该地点从表层水体流出的通量。* * *

9314533 Caron The symbiont-bearing planktonic sarcodines (Acantharia, Radiolaria and Foraminifera) are one of the most conspicuous groups of micro- /macrozooplankton in the surface waters of oceanic communities. They are also one of the least studied for their importance in energy flow, nutrient cycles and vertical fluxes in these environments. Planktonic sarcodines play an important role in the production of organic material by organisms 70 um in oceanic plankton communities (via their intracellular symbiotic algae). Moreover, by virtue of their large size (and consequently their potentially rapid sinking rates) they also play a greater role in the flux of material out of the mixed layer than would be predicted by their overall contribution to planktonic biomass. Previous studies indicate great variability in the surface productivity and flux of sarcodine material out of the mixed layer that may be related to the reproductive periodicities of some species of symbiont-bearing planktonic sarcodines or to episodic events leading to rapid population growth. This project will test this hypothesis, and determine the extent to which these periodicities control the temporal changes in the importance of planktonic sarcodines to primary production in the surface waters of the oligotrophic Atlantic Ocean near Bermuda, and to their flux out of the surface waters at this site. ***