球形棕囊藻囊体形成对摄食化学信息的响应

球形棕囊藻生活史中包含单细胞和囊体2种形态，囊体的形成有助于棕囊藻抵制摄食．通过添加海洋弯曲甲藻和中华哲水蚤的过滤液，研究球形棕囊藻囊体形态对可溶性摄食信息的响应．研究结果表明：海洋弯曲甲藻提高了球形棕囊藻的囊体数量和囊体体积，而中华哲水蚤的摄食压力促使囊体直径继续提高，近80％的球形棕囊藻细胞更多的以囊体形式存在，但是囊体结构并未有显著的改变；囊体形成和体积提高赋予球形棕囊藻优越的竞争策略，有效降低了摄食死亡率，有利于球形棕囊藻频繁形成大规模藻华．

Response of Colony Formation in Phaeocystis globosa to Grazing Chemical Cue

The genus Phaeocystis （Prymnesiophyceae） has a complex polymorphic life cycle that involves both colo- nial and solitary forms. Colony formation provides the protection to colonial cells against grazers. The response of P globosa colony formation to resolved chemical cues associated with grazing was examined after the addition of the filtrates derived from Oxyrrhis marina and Calanus sinicus. Results demonstrate that chemical cues from grazing 0. marina and copepod increased colony size in P. globosa, and that grazing information released by micro-grazing also enhances the colony amount. The percentage ofP globosa cells in colonial form increased when chemical cue released by grazer was present. However, the structure of colonies remained unchanged. Colony formation and increased size induced by grazing significantly suppress grazing military, and contribute to the development of bloom dominated by Phaeocystis.