The genus Thalassiosira off the Guangdong coast, South China Sea

We describe the taxonomy and species diversity of 35 taxa of the diatom genus Thalassiosira from a series of net plankton collected quarterly or monthly from eight locations off the Guangdong coastal waters in the South China Sea. Field samples and 14 cultured Thalassiosira clonal strains were studied by light and electron microscopy. A total of 35 Thalassiosira species were recorded, including nine new records for China, namely T. cedarkeyensis, T. densannula, T. duostra, T. hendeyi, T. nanolineata, T. nodulolineata, T. punctigera, T. tubifera and T. visurgis, and eight new records for Asia (taxa as above, except for T. punctigera). The morphological features of these Thalassiosira species are described and compared with previous illustrations. Some morphological variations are reported and discussed. This study was the first attempt to describe Thalassiosira species diversity in the South China Sea and Asian tropical waters. The results highlight a higher species diversity of Thalassiosira in the Guangdong coastal waters than in other studied regions.