phytoplankton

[Free-floating minute organisms that are photosynthetic. The term is non-taxonomic and refers to a lifestyle (energy utilization and motility), rather than a particular type of organism. Most, but not all, are unicellular ALGAE. Important groups include DIATOMS; DINOFLAGELLATES; CYANOBACTERIA; CHLOROPHYTA; coccolithophorids; CRYPTOMONADS; and silicoflagellates. ( MSH )]

UMLS (CSP) C0031865