Our research on phytoplankton and algae is fairly diverse in nature but currently focuses on dinoflagellates. Dinoflagellates are important primary producers, but there are also many species that are heterotrophic or mixotrophic. Many species in the family of Symbiodiniaceae are essential endosymbionts for the growth of reef-building corals. Dinoflagellates are also major contributors of harmful algal blooms or HABs (a.k.a red tides), and some of them produce toxins. Their genome is enormous, and their gene expression pattern and regulation are unusual compared to other eukaryotes. Our research spans from genomics to ecology, particularly with respect to two HABs and symbiosis.