Unarmoured dinoflagellates with a small hyposome:TorodiniumandLebouridiniumgen. nov. forKatodinium glaucum(Gymnodiniales, Dinophyceae)

We investigated the morphology and evolutionary relationships of Torodinium spp. and Katodinium glaucum, unarmoured dinoflagellates characterized by a small hyposome. An emended generic description of Torodinium was proposed based on light and scanning electron microscopy. Torodinium exhibited a unique combination of morphological features including a minute hyposome, a long episome with longitudinal ribs and a canal of unknown function on the...