What are Dinoflagellates?
Dinoflagellates are microscopic, (usually) unicellular, flagellated, often photosynthetic protists, commonly regarded as “algae” (Division Dinoflagellata). They are characterized by a transverse flagellum that encircles the body (often in a groove known as the cingulum) and a longitudinal flagellum oriented perpendicular to the transverse flagellum. This imparts a distinctive spiral to their swimming motion. Both flagella are inserted at the same point in the cell wall, by convention defining the ventral surface. This point is usually slightly depressed, and is termed the sulcus. In heterotrophic dinoflagellates (ones that eat other organisms), this is the point where a conical feeding structure, the peduncle, is projected in order to consume food. Dinoflagellates possess a unique nuclear structure at some stage of their life cycle – a dinokaryotic nucleus (as opposed to eukaryotic or prokaryotic), in which the chromosomes are perminently condensed. The cell wall of many dinoflagellate
