Species-specific productivity of Cryptomonas ovata (Cryptophyceae) in the Pal'tang Reservoir, Korea

Population dynamics and primary productivity of Cryptomonas ovata were investigated in a riverine zone of Pal'tang Reservoir from April through November in 1997. Standing crops of C. ovata ranged from 0.4 to 52% of total phytoplankton cell number. Its productivity varied from 2.8 to 137.9 mug Cl-1 hr(-1) (ca. 1 to 74 % of total productivity) and contributed ca. 28 % of total phytoplankton productivity on an annual basis. Species-specific productivity (SSP) of C ovata fluctuated between 14.6 and 81.5 pg C cell(-1) hr(-1) and its seasonal trend was not clear. Volume-specific SSP (SSP/cell volume) of C ovata was significantly higher in summer, which suggests high growth rate potential at higher temperatures (23-27 degreesC). However, the C. ovata population reached its maximam density in spring.