Planktonic

By taxon

• planktonic animals (metazoa) : – mostly predators (zooplankton) of smaller plankton. Examples are arrow worms, sea butterfly, ostracods, and salps. There are also planktonic microanimals typically smaller than one mm, such as copepods, water fleas, rotifers, and larval stages of various crustaceans and corals.
• planktonic protists: – single-celled eukaryote microorganisms, mostly invisible to the naked eye, such as diatoms, dinoflagellates, coccolithophores, foraminifera, radiolarians, and ciliates. Planktonic protists include algae (phytoplankton), protozoa (zooplankton), and many mixoplankton.
• planktonic fungi: – known also as mycoplankton, play important roles in remineralisation and nutrient cycling. For example, in the mycoloop, parasitic chytrids facilitate the transfer of nutrients from large, inedible phytoplankton to zooplankton.
• planktonic prokaryotes: planktonic bacteria and archaea known also as bacterioplankton and archaeoplankton. These play important roles as primary producers, or in remineralising organic material like mycoplankton down the water column. Photosyntheticcyanobacteria are important members of the phytoplankton. The unusually small Pelagibacter ubique, perhaps the most abundant bacterium on Earth, makes up about one third of microbial cells in the surface ocean, and plays important roles recycling nutrients in the microbial loop. The Roseobacter clade are significantly connected to phytoplankton.