日本虎斑猛水蚤在抑食金球藻中存活、发育和繁殖的实验研究

Experimental study on survival,growth,and reproduction of Tigriopus japonicus in Aureococcus anophagefferens-rich environments

抑食金球藻(Aureococus anophagefferens)可以形成褐潮,并对贝类、浮游动物等多种生物均能造成不利影响。为进一步探究抑食金球藻对浮游动物的影响,本文以日本虎斑猛水蚤(Tigriopus japonicus)为实验生物,研究抑食金球藻对日本虎斑猛水蚤摄食、存活、生长发育以及繁殖的影响。日本虎斑猛水蚤具有易于在实验室培养、生长周期短、雌雄异体等优点,是海洋毒性污染物检测的模式生物。实验利用高效液相色谱分析方法,在日本虎斑猛水蚤体内色素中检测到了抑食金球藻的特征色素19’-丁酰氧基岩藻黄素(But-fuco),表明日本虎斑猛水蚤能够摄食抑食金球藻。当微藻生物量(相对碳含量)分别同为0.7μg/mL和7.2μg/mL时,在抑食金球藻中无节幼体发育至桡足幼体及成体的存活率均高于以青岛大扁藻为饵料的对照组,但无显著差异,并且在前者中无节幼体的发育时间显著低于后者,12 d内雌体的产卵次数与产卵量显著高于后者。结果表明,日本虎斑猛水蚤在抑食金球藻中能进行正常的生命活动,并且是首次报导的一种能够在抑食金球藻中正常摄食、生存、生长发育和繁殖的浮游动物。因此,当褐潮发生时,由于贝类幼体等生物会受到显著的不利影响,日本虎斑猛水蚤等抗性较强的生物可能会成为优势种,从而会影响浮游动物群落结构的组成,进而可能会使整个海洋生态系统发生变化。本研究有助于全面了解褐潮对海洋生态系统的影响。

Aureococcus anophagefferens can cause brown tides and adversely affect numerous organisms,such as shellfish and zooplankton.To elucidate the influence of A.anophagefferens on zooplankton,this study used Ti-griopus japonicus to evaluate the effects of A.anophagefferens on T.japonicus feeding,survival,growth,and re-production.T.japonicus has several advantages,such as being easy to cultivate in the laboratory,short growth cycle,and sexual dimorphism;moreover,it is a marine model organism widely used to detect toxic pollutants.Herein,T.japonicus was used as the experimental organism,and Platymonas helgolandica was used as the control.The ex-periment used high-efficiency liquid chromatographic analysis methods and detected 19’-butyroxyfucoxanthin(But-fuco),a characteristic pigment of A.anophagefferens,in the internal pigment of T.japonicus,indicating that T.japonicus could ingest A.anophagefferens.When the algal biomass was 0.7μg/mL and 7.2μg/mL,the survival rate of nauplii to copepod and adults in A.anophagefferens-rich environmentswas higher than that in P.helgo-landica-rich environments;however,no significant difference was observed.Moreover,the development time of nauplii in A.anophagefferens-rich environments was lower than that in P.helgolandica-rich environments,and the number of eggs laid by females within 12 days was significantly higher in the former than those in the latter.Results revealed that T.japonicus could perform normal activities in A.anophagefferens-rich environments,reporting for the first time that zooplankton can normally feed,survive,develop,and reproduce in A.anophagefferens-rich envi-ronments.Therefore,when brown tides occur,more resistant organisms such as T.japonicus may become the dominant species considering the substantially adverse effects on other organisms such as shellfish larvae,which may affect the composition of the zooplankton community,ultimately affecting the entire marine ecosystem.Thus,this study contributes to a comprehensive understanding of the impact of brown tide on ecosystems.