不同摄食压力下球形棕囊藻的防御策略  

Defense Strategy of Phaeocystis globosa (Prymnesiophyceae) in Response to Different Grazing Pressure

作　　者：丁立 王小冬[1] 王艳[1] 

机构地区：[1]暨南大学赤潮与海洋生物学研究中心,广东广州510632

出　　处：《海洋科学进展》2018年第1期139-145,共7页Advances in Marine Science

基　　金：国家自然科学基金项目--异养甲藻的营养优化功能研究(41676144);国家重点基础研究发展计划项目--我国近海致灾赤潮形成机理;监测预测及评估防治研究(2017YFC1404301);中央高校基本科研业务费专项--新型溴代阻燃剂和有机磷阻燃及塑化剂在华南沿海浮游植物中生物富集(21615458)

摘　　要：球形棕囊藻是我国沿海常见有害藻华物种,生活史中包括囊体和单细胞两种形态,藻华爆发时的优势形态是囊体,游离单细胞很少被发现,但是球形棕囊藻囊体形成的机制目前还不清楚。本研究通过分析桡足类、纤毛虫和异养甲藻及其化学信号对囊体形成的影响,以探究摄食压力对球形棕囊藻生活史转变的影响。实验结果表明:3种摄食者的直接摄食均引发了球形棕囊藻囊体直径的扩大,摄食者的粒径越大,球形棕囊藻的囊体直径增大越显著,安氏伪镖水蚤的化学信号也能引发球形棕囊藻囊体显著增大,但是游仆虫和海洋尖尾藻的化学信号并未引发类似响应。囊体形成和直径的扩大保护了囊体内细胞免受摄食,有助于球形棕囊藻藻华的发生。Phaeocystis,a harmful algal species,has a unique polymorphic life cycle that involves the transformation between solitary cells and colonies.The colonial form is often the dominant morphotype during Phaeocystis blooms,but the transformation mechanism during the life cycle remains unclear.We conducted experiments in which cultures of P.globosa were exposed to copepods,ciliates and heterotrophic dinoflagellates as well as their chemical cues to study the effects of grazing on the life cycle in P.globosa.Our results demonstrated that colony diameters of P.globosaincreased significantly in the presence of three grazers and the chemical cues of Pseudodiaptomus annandaleis.The increase in diameter was dependent on the size of grazers.However,chemical cues released by Eupoltes sp.and Oxyrrhis marina did not cause increase in colony size.Therefore,colony formation and diameter enlargement could be considered as an induced defensing strategy which protecte the from being prey and may contribute to the bloom of Phaeocystis in marine ecosystems.

关 键 词：球形棕囊藻 有害藻华 摄食 囊体形成 生活史 

分 类 号：P76[天文地球—海洋科学]