中国科学院海洋研究所机构知识库

  牡蛎是营固着生活的软体动物，贝壳形态变化极大，容易随环境变化而变化，传统的贝壳形态及解剖结构等鉴定方法对牡蛎进行分类容易导致分类的混乱。小蛎属（Saccostrea）牡蛎只分布在热带及亚热带水域，在我国南方沿海潮间带最为常见、数量最大，大多数种类附着于裸露的岩石上或附着在珊瑚礁上，其壳形特征在各种间有相似性，因此小蛎属牡蛎的分类更为混乱。本次研究在传统形态分类的基础上，利用线粒体基因细胞色素氧化酶Ⅰ（COI）、16SrRNA和核基因28SrRNA对中国沿海的小蛎属牡蛎的分类演化以及地理分布进行了系统分析。

  从中国浙江以南沿海潮间带共采集到1773个小蛎属牡蛎样品，鉴定出7种小蛎属牡蛎，其中包括2个新种，2个新纪录种，分别为小蛎属新种拟咬齿牡蛎（S. mordoidea sp. nov.）、拟多刺牡蛎（S. kegakioidea sp. nov.），小蛎属中国沿海新纪录种马拉邦牡蛎（S. malabonensis）和旋形牡蛎（S. circumsuta），以及3种中国沿海小蛎属常见种，即咬齿牡蛎（S. mordax）、棘刺牡蛎（S. echinata）和多刺牡蛎（S. kegaki）。拟咬齿牡蛎数量较少，仅在海南海棠湾有分布，拟多刺牡蛎仅在浙江南麂岛和嵊泗列岛有发现。马拉邦牡蛎样品数量较多，主要分布在广东和海南沿海潮间带。旋形牡蛎样品数量较少，主要分布在广东、香港、广西以及海南沿海潮间带。咬齿牡蛎在广东阳江市和海南沿海潮间带都有分布。多刺牡蛎在浙江沿海，嵊泗列岛，南麂岛以及东冲半岛潮间带岩石上有发现。棘刺牡蛎样品数量最多，在浙江、福建、广东、广西以及海南沿海潮间带都有分布。

  本次研究确定了中国沿海小蛎属牡蛎的种类及分布，根据线粒体基因（16SrRNA、COI）和核基因（28SrRNA）构建了小蛎属的系统进化树，确定了小蛎属牡蛎的种间关系。为生物多样性调查保护、生态研究以及水产养殖等提供依据。

  Oysters have high morphological plasticity and are easy to change their shell characteristics with the environment. The traditional classification mainly based on shell morphology and anatomical structure, which can lead to the confusions on oyster classification. Saccostrea oysters restrictly distribut to tropical and subtropical waters. Saccostrea is the most common and most abundant oyster in the southern coastal zone of China, most species are attached to exposed rocks or coral reefs. The shell morphology of Saccostrea species are similarity, so the classification on Saccostrea oyster is more controversial. Based on traditional morphological classification, this study analysed the classification of genus Saccostrea using mitochondrial genes of cytochrome oxidase I (COI) and 16SrRNA and nuclear gene 28SrRNA calrified the distribution of Saccostrea from coastal intertidal zone of China.

  In present study, we collected 1773 oysters of Saccostrea, and identified seven species including two new species and two new records of Chinese waters. S. mordoidea sp. nov. and S. kegakioidea sp. nov. are two new species. The two new records include S. malabonensis and S. circumsuta. The remaining three oysters are common oysters on China's coastal intertidal. They are S. mordax, S. kegaki and S. echinata. Currently, S. mordoidea sp. nov. is distributed in Haitang bay in Hainan Province. S. kegakioidea sp. nov. is found only in Nanji Islands and Shengsi Islands of Zhejiang Province. S. malabonensis is abundant, and mainly distributes in Guangdong and Hainan coastal intertidal. There are a few individuals of S. circumsuta, distributed in Guangdong, Hong Kong, Guangxi and Hainan coastal intertidal. S. mordax is distributed in Yangjiang Guangdong Province and Hainan coastal intertidal, where S. kegaki is found on exposed rocks in Nanji Islands, Shengsi Islands, Zhejiang coastal intertidal and Dongchong Peninsula. S. echinata is the largest and most widely spread oysters, distributed in Zhejiang, Fujian, Guangdong, Guangxi and Hainan coastal intertidal.

  This research clarified the classification confusion of genus Saccostrea along China's coastal intertidal, and determined their distribution. According the phylogenetic tree of the genus Saccostrea established using the mitochondrial gene (16SrRNA and COI) and nuclear gene (28SrRNA), the interspecies relationship of genus Saccostrea oyster was determined. This study provides the basic information for biodiversity investigation conservation, ecological research and aquaculture.

摘 要.... I

ABSTRACT.. II

第一章 绪论.... 1

1.1 引言... 1

1.1.1 分子系统学... 1

1.1.2 小蛎属（Saccostrea）分类地位... 2

1.1.3 小蛎属牡蛎分类学特征... 2

1.2 牡蛎总科（Ostreoidea）研究简史... 2

1.3 小蛎属研究简史... 4

第二章 小蛎属牡蛎的系统分类.... 9

2.1 材料与方法... 9

2.1.1 样品的采集... 9

2.1.2 样品形态学分析... 9

2.1.3 基因组DNA的提取、目的片段扩增和序列测定... 11

2.1.4 遗传距离和系统发育分析... 12

2.2 结果分析... 13

2.2.1 中国沿海小蛎属牡蛎地理分布及形态学分析... 13

2.2.1.1 小蛎属新种拟咬齿牡蛎S. mordoidea sp. nov. 13

2.2.1.2 小蛎属新种拟多刺牡蛎S. kegakioidea sp. nov. 16

2.2.1.3 马拉邦牡蛎Saccostrea malabonensis (Faustino, 1932) 18

2.2.1.4 旋形牡蛎Saccostrea circumsuta (Gould, 1850) 19

2.2.1.5 咬齿牡蛎Saccostrea mordax (Gould, 1850) 21

2.2.1.6 棘刺牡蛎Saccostrea echinata (Quoy & Gaimard, 1835) 23

2.2.1.7 多刺牡蛎Saccostrea kegaki Torigoe & Inaba, 1981. 25

2.2.2 小蛎属牡蛎的分子系统学分析... 26

2.2.2.1 基于16S rRNA基因构建小蛎属系统进化树... 26

2.2.2.2 基于16S rRNA基因的小蛎属牡蛎种间遗传距离... 30

2.2.2.3 基于COI基因构建小蛎属系统进化树... 34

2.2.2.4 基于COI基因的小蛎属牡蛎种间遗传距离... 36

2.2.2.5 基于28S rRNA基因构建小蛎属系统进化... 40

2.2.2.6 基于28S rRNA基因的小蛎属牡蛎种内和种间遗传距离... 41

2.2.3 讨论... 41

2.2.3.1 小蛎属新种拟咬齿牡蛎S. mordoidea sp. nov. 41

2.2.3.2 小蛎属新种拟多刺牡蛎S. kegakioidea sp. nov. 43

2.2.3.3 马拉邦牡蛎S. malabonensis. 43

2.2.3.4 旋形牡蛎 S. circumsuta. 44

2.2.3.5 咬齿牡蛎S. mordax. 44

2.2.3.6 棘刺牡蛎S. echinata. 45

2.2.3.7 多刺牡蛎S. kegaki 46

2.2.3.8 小蛎属未定种Saccostrea sp.1和Saccostrea sp.2. 46

2.2.3.9 僧帽牡蛎S. cucullata (Born, 1778) 46

第三章 小蛎属牡蛎的地理分布.... 49

第四章 总结.... 51

参考文献.... 53

附录.... 59

致 谢.... 63

作者简历及攻读学位期间发表的学术论文与研究成果.... 65