Organisms of the Sea

 Plankton, Greek word planktos meaning “wandering”, just swim weakly usually just drifting with the current  Plankton can be drifting jellyfish with 25 foot long tentacles, small arrow worms, small single celled organisms, crustaceans that look like small crabs and microorganisms  All plankton share 1 thing in common – their inability to swim against ocean current Plankton

 A huge layer of phytoplankton drift within the sunlit layer of the ocean  There are a few different kinds of phytoplankton  Diatoms – special extra pigments to absorb sunlight for more efficient photosynthesis  Dinoflagellates – have two flagella for movement  Coccolithophores – covered in Calcium, in large numbers they can make the water look milky  Nanoplankton and Picoplankton – very small Phytoplankton – The Autotrophs

DD Phytoplankton diatoms coccolithophore dinoflagellates

 Algae – organisms with chlorophyll in the ocean  Seaweed – a general term for large marine algae Other Autotrophs

 The most numerous primary consumers in the ocean  They graze on the diatoms and dinoflagellates much like a cow on grass  The most common are shrimp like creatures called copepods Zooplankton – The Heterotrophs