The Gymnodiniales are an order of dinoflagellates, of the classDinophyceae.[2] Members of the order are known as gymnodinioid or gymnodinoid (terms that can also refer to any organism of similar morphology). They are athecate, or lacking an armored exterior, and as a result are relatively difficult to study because specimens are easily damaged. Many species are part of the marine plankton and are of interest primarily due to being found in algal blooms. As a group the gymnodinioids have been described as "likely one of the least known groups of the open ocean phytoplankton."[3]
^Landsberg, J.H.; Flewelling, L.J.; Naar, J. (March 2009). "Karenia brevis red tides, brevetoxins in the food web, and impacts on natural resources: Decadal advancements". Harmful Algae. 8 (4): 598–607. doi:10.1016/j.hal.2008.11.010.