First record of genera Rutilaria and Trigonium (Bacillariophyta) and 11 diatom taxa (species and varieties) in South China Sea

Diatom taxa in samples collected from the uppermost 1-cm sediment of the South China Sea (SCS) during cruises in 2000, 2001, and 2007 were investigated. Among them, two genera, Rutilaria and Trigonium, and 11 marine taxa (species and varieties) were described for the first time in China. The 11 taxa, Rutilaria radiata, Asterolampra grevillei, Biddulphia turrigera, Cocconeis cyclophora var. decora, Cocconeis ocellata, Dictyoneis marginata, Entogonia davyana, Tryblionella campechiana, Plagiogramma kinkeri, Plagiogramma nankoorense and Trigonium cf. contumax, were mainly extant species, although Rutilaria radiata and Entogonia davyana are fossils. Available data show that these species are mainly present in the eastern and western Pacific Ocean and the Indian Ocean. A large number of taxa newly recorded in this study were previously reported in the Philippines. The presence of these taxa in both locations is likely a result of seawater exchange in the SCS through the Bashi Channel. Taxonomic descriptions, habitats, and distributions of each diatom taxon are provided herein.