论文部分内容阅读
An unarmored dinoflagellate bloom of Cochlodinium geminatum (Schutt) Schutt has been identified in the Pearl River Estuary, South China Sea during the severe dry season, from late October to early November, 2009, when temperature and salinity ranged between 20.0~27. 2℃ and 10. 6～33.4, respectively. Light and scanning electron microscopy were used to identify the characteristics of C. geminatum and provided the clear morphological structure for this species. The organism was primarily found in chains of two cells or single cell, and no longer chains were observed. Cells were irregularly spherical or slightly dorso-ventrally, with size ranged between 28-36 μm and longer than wide. A large nucleus in the center with numerous golden chloroplasts was present, and the cingulum made 1. 5 turns around the cell. The concentration of C. geminatum ranged from 102 to greater than 107 cells 1-1 during the bloom period. Nutrient concentration ranges during the bloom were 1. 29-81. 00 μM N03, 0. 14-12.14 μ M N02, 0. 21-6. 29 μ M NH4, 0.23-6.26 μM PO4 and 3.29-171.43 uM SiO3, respectively.