Navicula is a genus of boat-shaped algae — primarily aquatic, eukaryotic, photosynthetic organisms, ranging in size from a single cell.
Navicula is a diatom. The Navicula genus of diatoms comprises more than 10,000 species. Navicula is Latin for "small ship", and also a term in English for a boat-shaped incense-holder.
Navicula play an important role in global ecology, producing about a quarter of all the oxygen within Earth's biosphere and serving as keystone species in the food chain of many environments where they provide a staple for the diets of many aquatic species.