Abstract：
Diatoms of the genus Pseudo-nitzschia are widespread in marine waters. Some of them can produce the toxin domoic acid (DA) which can be responsible for amnesic shellfish poisoning (ASP) when transferred into the food web. These ASP events are of major concern, due to their ecological and socio-economic repercussions, particularly on the shellfish industry. Many studies have focused on the influence of abiotic factors on DA induction, less on the role of biotic interactions. Recently, the presence of predators has been shown to increase DA production in several Pseudo-nitzschia species, in particular in Arctic areas. In order to investigate the relationship between Pseudo-nitzschia species and grazers from the French coast, exposures between one strain of three species (P. australis, P. pungens, P. fraudulenta) and the copepod Temora longicornis were conducted for 5 days. Cellular and dissolved DA content were enhanced by 1,203 % and 1,556 % respectively after the 5-days exposure of P.australis whereas no DA induction was observed in P. pungens and P. fraudulenta. T. longicornis consumed all three Pseudo-nitzschia species. The copepod survival was not related to DA content. This study is an essential first step to better understanding the interactions between planktonic species from the French coast and highlights the potential key role of copepods in the Pseudo-nitzschia bloom events in the temperate ecosystems.
摘要：
假硝化菌属的硅藻广泛分布在海水中。它们中的一些可以产生毒素软骨酸（DA），当转移到食物网中时，该毒素可能会导致失忆贝类中毒（ASP）。这些ASP事件是主要关注的问题，由于它们的生态和社会经济影响，特别是贝类产业。许多研究都集中在非生物因素对DA诱导的影响，对生物相互作用的作用较少。最近,捕食者的存在已被证明可以增加几种伪硝虫物种的DA产量，特别是在北极地区。为了调查法国海岸的伪硝虫物种与食草动物之间的关系，三种物种中的一种菌株之间的暴露(P.澳大利亚，P.pungens,P.fragulenta）和co足类Temoralongicornis进行了5天。暴露5天后，细胞和溶解的DA含量分别增加了1,203％和1,556％，而在P.pungens和P.frag.T.longicornis消耗了所有三种伪氮菌。co足类的存活与DA含量无关。这项研究是更好地了解来自法国海岸的浮游物种之间相互作用的重要第一步，并强调了co足类在温带生态系统中Pseudo-nitzschia开花事件中的潜在关键作用。
