Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaysia, Bachok, 16310, Kelantan, Malaysia.
Faculty of Applied Sciences, Tunku Abdul Rahman University College, Johor Branch Campus, 85000, Segamat, Johor, Malaysia.
Harmful Algae. 2019 Nov;89:101671. doi: 10.1016/j.hal.2019.101671. Epub 2019 Oct 5.
Species of the benthic dinoflagellate Gambierdiscus produce polyether neurotoxins that caused ciguatera fish/shellfish poisoning in human. The toxins enter marine food webs by foraging of herbivores on the biotic substrates like macroalgae that host the toxic dinoflagellates. Interaction of Gambierdiscus and their macroalgal substrate hosts is believed to shape the tendency of substrate preferences and habitat specialization. This was supported by studies that manifested epiphytic preferences and behaviors in Gambierdiscus species toward different macroalgal hosts. To further examine the supposition, a laboratory-based experimental study was conducted to examine the growth, epiphytic behaviors and host preferences of three Gambierdiscus species towards four macroalgal hosts over a culture period of 40 days. The dinoflagellates Gambierdiscus balechii, G. caribaeus, and a new ribotype, herein designated as Gambierdiscus type 7 were initially identified based on the thecal morphology and molecular characterization. Our results showed that Gambierdiscus species tested in this study exhibited higher growth rates in the presence of macroalgal hosts. Growth responses and attachment behaviors, however, differed among different species and strains of Gambierdiscus over different macroalgal substrate hosts. Cells of Gambierdiscus mostly attached to substrate hosts at the beginning of the experiments but detached at the later time. Localized Gambierdiscus-host interactions, as demonstrated in this study, could help to better inform efforts of sampling and monitoring of this benthic toxic dinoflagellate.
底栖腰鞭毛虫中的物种产生聚醚神经毒素，这些毒素会导致雪卡鱼/贝类中毒。毒素通过草食动物摄食含有毒性腰鞭毛虫的生物基质（如大型藻类）进入海洋食物网。腰鞭毛虫与其大型藻类基质宿主的相互作用被认为会影响基质偏好和栖息地特化的趋势。这一点得到了研究的支持，这些研究表明了不同的大型藻类宿主对 Gambierdiscus 物种的附生偏好和行为。为了进一步检验这一假设，进行了一项基于实验室的实验研究，以检查三种 Gambierdiscus 物种在 40 天的培养期内对四种大型藻类宿主的生长、附生行为和宿主偏好。最初根据外壳形态和分子特征鉴定了 Gambierdiscus balechii、G. caribaeus 和一种新的核糖体型，称为 Gambierdiscus 型 7。我们的结果表明，在有大型藻类宿主存在的情况下，本研究中测试的 Gambierdiscus 物种表现出更高的生长速率。然而，不同的 Gambierdiscus 物种和菌株对不同的大型藻类基质宿主的生长反应和附着行为存在差异。 Gambierdiscus 细胞在实验开始时主要附着在基质宿主上，但后来又脱落。本研究中显示的局部 Gambierdiscus-宿主相互作用有助于更好地指导对这种底栖有毒腰鞭毛虫的采样和监测工作。
