Little did I know that the bio-luminescent phytoplankton known as Dinoflaggellates are actually predators and eat other phytoplankton. While the rest are busy sequestering carbon and producing oxygen, these ones are hunting their own.
http://www.mnh.si.edu/highlight/sem/dinoflagellates.html
http://oceandatacenter.ucsc.edu/PhytoGallery/Dinoflagellates/lingulodinium.html