| 摘要: |
| 近年来，我国海州湾浒苔暴发呈常态化趋势发展，日益威胁到该海域生态系统的健康。浒苔每年都会由南向北漂移经过平岛海域，在平岛海洋牧场中牡蛎是其重要的经济贝类，具有数量多、分布广、生态种群稳定等特点，浒苔对海洋牧场中这种滤食性经济贝类的影响亟待了解。使用传统的显微镜检测方法并不能准确鉴定出胃含物中有机物碎片成分，而应用DNA条形码技术则可以快速有效的判断这类摄食者的食物碎片来源。在本研究中，采集了浒苔发生前后不同时间的海州湾平岛海域特定区域的牡蛎。通过高通量DNA测序技术研究了其真核食物成分。扩增18S rDNA V4区共得到53347个有效序列短片段，聚类后得到105个类别，主要属于链形植物门（包括轮藻门和有胚植物（现存的陆生植物：苔藓维管植物）两大类）、绿藻门、囊泡虫门、子囊菌门等。其中，5月（WH1）、6月（WH2）、7月（WH3）、10月（WH4）的胃含物样品中分别发现了11、12、11和14个门的生物种类。进一步对WH1—WH4样品属水平进行聚类分析发现真核生物成分表现出显著的季节性差异，但在所有组当中并未发现石莼属或浒苔属成分。WH1样品中梨属和四胞藻纲含量最多。WH2样品中的子囊菌属和稻属含量均为4个样品中的最高值。WH3中共甲藻目的含量达到最高。WH4样品中沟鞭藻属的含量达到最高值。研究表明，牡蛎并没有直接摄食浒苔或石莼属成分，因此推断浒苔并不直接影响牡蛎的摄食情况。另外本研究首次发现被子植物在牡蛎胃含物中占有很高的比重，表明牡蛎食物源除来源于海洋外还有陆源有机质。 |
| 关键词: 浒苔绿潮 胃含物 真核生物 18S rDNA 牡蛎 |
| DOI：10.11693/hyhz20170700189 |
| 分类号:Q14 |
| 基金项目:中国科学院战略性先导科技专项（A类）资助，XDA11020700号；鳌山科技创新计划项目资助，2016ASKJ02号；国家自然科学基金青年科学基金项目资助，41606171号。 |
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| IMPACT OF ENTEROMORPHA PROLIFERA GREEN TIDE ON OYSTER FEEDING USING 18S rDNA MOLECULAR METHOD |
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WANG Xian-Feng1,2, LIN Cheng-Gang2, XU Qiang3, SONG Xiao-Yue2, ZHANG Hai-Jian4, RU Shao-Guo1, YANG Hong-Sheng2
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1.Ocean University of China, Qingdao 266003, China;2.CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China;3.Hainan University, Haikou 570228, China;4.Rizhao Fishery Communication Management Station, Rizhao 276800, China
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| Abstract: |
| Incidents of green tides occurred frequently in Chinese waters in recent year. It is necessary to study its impact on suspension-feeder bivalves. However, the majority of organic debris in stomach cannot be identified reliably and accurately by microscopic examination. Advanced DNA barcoding becomes therefore an effective and rapid technique to determine dietary composition of those bivalves. We samples mussels in the Haizhou Bay, Pingshan Island before and after an Enteromorpha blooming. The eukaryotic food composition in the mussel samples was determined by high-throughput DNA sequencing, and amplified the 18S rDNA v6 loci sequences. From which 53347 reads were optimized and 105 operation taxonomic units were recognized. They were classified mainly into Streptophyta, Chlorophyta, Ascoaamycota, and Protalveolata etc. Among them, organisms belonging to 11, 12, 11, and 14 phyla were found in stomach contents of the samples collected in May (Sample No.WH1), June (WH2), July (WH3), and October (WH4), respectively. Furthermore, cluster analysis showed significant seasonal differences in various eukaryotic components in these samples, but no Ulva contents were detected. Trebouxiophyceae and Pyrus were observed the highest in WH1; Dothidea and Oryza the highest in WH2; Syndiniales in WH3; and Biecheleria in WH4. The present study indicates that the green tide did not affect the food source of mussel directly. It is the first report on that angiosperms occupies a high proportion in the stomach content of mussel, suggesting that the food source of mussel is derived from both marine and terrestrial organic sources. |
| Key words: green tide stomach content eukaryotes 18S rDNA Ostrea gigas Thunberg |
