Mixoplankton are now recognized as an important functional group of plankton and include many harmful algal bloom (HAB) forming species. One promising method to identify these mixoplankton, which is not destructive and will allow enumeration, is the Imaging FlowCytobot (IFCB). IFCB combines flow cytometry and video technology to capture images of individual plankton cells. Continuous automated operation and data processing has produced a high-resolution time series of the microplankton community structure and has demonstrated the successful use of this instrument for HAB early warning. Sustained operation of this novel technology at the Texas Observatory for Algal Succession Time series (TOAST) in Port Aransas, TX since 2007 and Surfside Beach, TX since 2017 has provided observations of Dinophysis ovum and its prey, Mesodinium rubrum. In addition to detection and successful early warning of HAB events, time series data have been used in developing models to identify important factors in bloom initiation of Dinophysis ovum. Model results showed a strong effect of water temperature on Dinophysis  bloom onset; blooms occurred as waters warmed and overlapped with the optimal temperature range for Dinophysis growth (18 – 24 oC). Allowing biomass of predator and prey to vary within the model showed a notable sensitivity of Dinophysis bloom intensity and duration to prey size.