Sedimentary chrysophycean stomatocysts from an alpine lake in the Three Gorge Reservoir region, central China

The mountainous terrain and warm-humid climates have fostered rich biodiversity in central China. Several national nature reserves have been listed on the World Network of UNESCO Biosphere Reserves. In this study, morphological characteristics of chrysophycean stomatocysts were analyzed in a 33-cm-long sediment core from Mulong Lake, a small alpine lake in the Three Gorges Reservoir region, central China. Thirty-two morphotypes of stomatocysts were identified in the sediment core according to the International Statospore Working Group guidelines, and illustrated by SEM micrographs. Of thirty-two cyst types, four cyst types were described as new to science. These stomatocysts generally prefer oligotrophic, electrolyte-poor and cold environments. This study highlights rich morphotypes of chrysophycean stomatocysts in alpine lakes of the subtropical monsoonal region, meanwhile, our results can create a taxonomical basis for further palaeoecological study in this lake, as well as similar alpine lakes.