Marine life live in the water column of large bodies of water and that cannot swim against a current. They provide a crucial source of food to many large aquatic organisms, such as fish and whales. These organisms include drifting or floating bacteria, archaea, algae, protozoa and animals that inhabit, for example, the pelagic zone of oceans, seas, or bodies of fresh water. Essentially, plankton are defined by their ecological niche rather than any phylogenetic or taxonomic classification. Though many planktonic species are microscopic in size, "plankton" includes organisms covering a wide range of sizes, including large organisms such as jellyfish. The
Telonemia Telonemia Telonemia is a phylum of microscopic eukaryote, single-celled organisms. They were formerly classified as protists until that kingdom fell out of general use, and are suggested to have evolutionary significance in being a possible transitional form between ecologically important heterotrophic and photosynthetic species among chromalveolates. One paper places them in the SAR supergroup. Phylogenomic analyses of 127 genes place Telonemia with Centroheliozoa in a group also consisting of cryptomonads and haptophytes (see Cryptomonads-haptophytes assemblage). Although they have been studied in primarily marine environments, they have also been found in freshwater. Shalchian-Tabrizi "et al" say that 18S rDNA sequences in