Pseudo-nitzschia species frequently blooms in coastal waters, and some species are able to produce the toxin domoic acid (DA), hereby causing harm to the marine ecosystem and humans. Laboratory studies were conducted to investigate the influence of different levels of grazing pressure on the morphological and chemical response (in terms of cellular DA production) of Pseudo-nitzschia. Subsequently, zooplankton grazer responses to these defenses were examined. The cellular DA content of P. multiseries ranged from 0.11-0.27 pg cell⁻¹ without grazers, and increased up to 44% with the presence of grazers (Artemia nauplii) and with grazer concentration. Grazing also affected the density of P. multiseries chains and average chain length which became ~25% higher and ~8% longer, respectively, than without grazers. These effects could either be caused by size-dependent grazing or by grazer-cue-induced effects on chain formation. A negative correlation between cellular DA content in P. multiseries and clearance and/or ingestion rates of Artemia nauplii indicate that DA might have a negative effect on the grazing of Artemia nauplii. Such interaction might result in a decrease in grazing pressure on toxic blooming species, like P. multiseries, and hence potentially a prolonged bloom. This indicates that the interaction between toxic diatoms and grazers may have implications on aquatic food web structure and the progression of Pseudo-nitzschia blooms.

拟南芥属物种经常在沿海水域开花，某些物种能够产生毒素二氢酸（DA），从而对海洋生态系统和人类造成伤害。进行了实验室研究，研究了不同层次上的形态和化学反应放牧压力的影响（以细胞DA生产方面）的拟菱形藻。随后，研究了浮游动物放牧者对这些防御措施的反应。的蜂窝DA内容P. multiseries从0.11-0.27皮克细胞介于^-1而不食草动物，并上升到44％与食草动物的存在（卤虫无节幼体），并用浓度食草动物。放牧还影响了P. multiseries的密度链和平均链长分别比不使用放牧者高25％和长8％。这些影响可能是由大小相关的放牧引起的，也可能是由放牧者提示对链形成的影响引起的。蜂窝DA含量呈负相关P. multiseries和清除和/或摄食率卤虫无节幼体表明，DA可能对的放牧造成负面影响卤虫无节幼体。这种相互作用可能会导致放牧对有毒开花物种（如P. multiseries）的放牧压力降低，因此可能会延长开花时间。这表明有毒硅藻与放牧者之间的相互作用可能对水生食物网的结构和成虫的进程有影响。拟南芥开花。