Silica-scaled chrysophytes from Hainan, Guangdong Provinces and Hong Kong Special Administrative Region, China

Twenty five phytoplankton samples containing chrysophytes were collected in Hainan and Guangdong Provinces and in Hong Kong Special Administrative Region in January 2010 and October to November 2011. Forty nine taxa of silica-scaled chrysophytes were identified by means of transmission electron microscopy, twelve of them belonging to Paraphysomonadaceae and thirty seven to Synurales. Spiniferomonas cornuta, Paraphysomonas sp., Mallomonas hexareticulata, M. ceylanica, M. plumosa, M. ocellata, M. elevata and M. spinosa are reported for the first time from China. A new species, Paraphysomonas hainanensis Wei & Kristiansen, was found in a pond in Haikou City, Hainan Province. An amended description of Mallomonas spinosa Gusev is proposed. The sampled localities are situated in the tropical and subtropical region of southern China. There is great similarity in the geographical distribution of the observed silica-scaled chrysophytes with that of east Asia, southeast Asia and south Asia, and their ecological characteristics are discussed.