Mitochondrial DNA and morphological identification of Crassostrea zhanjiangensis sp. nov. (Bivalvia: Ostreidae): a new species in Zhanjiang, China
Mitochondrial DNA and morphological identification of Crassostrea zhanjiangensis sp. nov. (Bivalvia: Ostreidae): a new species in Zhanjiang, China
复制标题
DOI：
10.1051/alr/2013065
复制
发表时间：
2013-10
影响因子：
1.1
通讯作者：
Xiangyun Wu;Shu Xiao;Ziniu Yu
中科院分区：
文献类型：
--
作者：
Xiangyun Wu;Shu Xiao;Ziniu Yu
杯形牡蛎（Ostreidae， Crassostrea属）在世界范围内占据近岸海洋和河口栖息地，提供许多生态系统产品和服务，同时也是一种重要的商业双壳类动物。本研究首次利用分子标记（部分线粒体cox1和rrnL基因）、系统发育分析和形态计量学方法，确定了一种常被误认为是其他同域物种（包括C. sikamea和C. hongkongensis）“年轻个体”的小体“假”牡蛎的物种鉴定。广东湛江市官渡湾牡蛎养殖区内的新物种C. zhanjiangensis，俗称“猫耳牡蛎”，由于在牡蛎采集设备上的生态位竞争，可能会影响C. hongkonggensis的贝采集效率。系统发育分析证实它是印度-太平洋长牡蛎纲中最基础的分类群。通过对湛江蛤壳特征的比较研究，我们发现了湛江蛤壳与其他蛤壳类的一些独特的形态特征，包括一般较小的体型，深杯状的左瓣，成虫的右瓣是凸的，而幼虫的右瓣是平的。该新种的其他显著特征还包括与同域的香港C. hongkongensis和sikamea物种相比所特有的生命周期特征，例如在定居后的快速生长期有较高的生长速度，随后在随后的生命阶段有明显较慢的生长速度和大量死亡。本研究为进一步对该新种进行生态学和种群遗传学研究提供了必要的基础资料。
Cupped oysters (Ostreidae, genus Crassostrea) occupy nearshore marine and estuarine habitats worldwide, providing many ecosystem goods and services as well as being a commercially important group of bivalves. In this study, the species identification of an "adulterant" oyster with small body size, which is often misidentified as a "young individual" of other sympatric species, including C. sikamea and C. hongkongensis, was determined for the first time, based on molecular markers (partial mitochondrial cox1 and rrnL genes), phylogenetic analysis, and morphometric approaches. This novel species, C. zhanjiangensis, commonly known as the "cat ear oyster" in Guandu (a famous estuarine oyster farming region of Zhanjiang, Guangdong Province, China), appears to potentially influence the efficiency of C. hongkongensis spat collection due to niche competition on spat collection devices. Phylogenetic analyses confirm its status as the most basal taxon of the Indo-Pacific Crassostrea. A comparative study of the shell characteristics of C. zhanjiangensis, and other Crassostrea species revealed several distinctive morphological traits, including a generally smaller body size, a deeply cupped left valve, and a right valve that is convex in adults but flat in young individuals. Other distinctive features of the new species include life cycle traits that are unique compared with the sympatric C. hongkongensis and C. sikamea species, such as a higher growth rate in the fast growth phase after settlement, followed by a significantly slower growth rate and mass mortality during subsequent life stages. This study provides the basic information necessary for further ecological and population genetic studies on this new species.