Nanophytoplankton Nanophytoplankton Nanophytoplankton are particularly small phytoplankton with sizes between 2 and 20 µm. They are the autotrophic part of nanoplankton. Like other phytoplankton, nanophytoplankton are microscopic organisms that obtain energy through the process of photosynthesis and must therefore live in the upper sunlit layer of ocean or other bodies of water. These microscopic free-floating organisms, including algae, and cyanobacteria, fix large amounts of carbon which would otherwise be released as carbon dioxide.. The term nanophytoplankton is derived from the far more widely used term nannoplankton/nanoplankton. Phytoplankton form the beginning of the food chain for aquatic animals. Zooplankton and krill feed
Plant or multicellular marine organisms such as the sea lettuce, "Ulva". The other group within the Viridiplantae are the mainly freshwater or terrestrial Streptophyta, which consists of the land plants together with the Charophyta, itself consisting of several groups of green algae such as the desmids and stoneworts. Streptophyte algae are either unicellular or form multicellular filaments, branched or unbranched. The genus "Spirogyra" is a filamentous streptophyte alga familiar to many, as it is often used in teaching and is one of the organisms responsible for the algal "scum" on ponds. The freshwater stoneworts strongly resemble land plants and are believed