%A Chen Zuoyi, Xu Xiaojing, Zhu Suying, Zhai Mengyi, Li Yang %T Species diversity and geographical distribution of the Chaetoceros lorenzianus complex along the coast of China %0 Journal Article %D 2019 %J Biodiv Sci %R 10.17520/biods.2018261 %P 149-158 %V 27 %N 2 %U {https://www.biodiversity-science.net/CN/abstract/article_59817.shtml} %8 2019-02-20 %X

The Chaetoceros lorenzianus complex is composed of several planktonic diatom species that share a similar morphology with C. lorenzianus Grunow. The complex has been recorded frequently in coastal waters across the world. Recently, new taxonomic information has enriched the known species diversity of the complex from 3 to 7 taxa. However, the identities of many species comprising the complex in China is still unclear. To clarify the species diversity and provide solid identification criteria for further studies, 332 monoclonal strains belonging to the C. lorenzianus complex were collected from the coast of China. With light microscopy and scanning and transmission electron microscopy, the morphologies of vegetative cells and resting spores were observed. Hypervariable D1-D3 regions of nuclear large subunit ribosomal encoded genes were amplified to construct the phylogenetic relationship. Morphological clustering was consistent with molecular systematics, which indicated that a total of 5 species are present within the C. lorenzianus complex along the coast of China; C. decipiens, C. elegans, C. laevisporus, C. mannaii and C. pauciramosus. The ultrastructure on setae, such as the shape, size and density of the setae pores, can be used as distinguishing features among allied taxa. The morphology of the resting spores also aid in accurate identification. The previous reports identifying the taxa within the C. lorenzianus complex in China need to be reexamined. Chaetoceros decipiens and C. laevisporus are the most widespread taxa along the coast of China, whereas C. pauciramosus has the narrowest distribution, having only been recorded in Taishan and Zhuhai of the Guangdong Province.