What are the general features of the prymnesiophyceae

Prymnesiophyceae is an algal class. It is placed in the haptophyte clade.It is unicellular.It has flagella (usually two) known as haptonema. These structures help in attachment and feeding.The plastids are surrounded by four-layered membranes.Its species are mostly found in the marine environment, thus classified as phytoplanktons.Many members of prymnesiophyceae have cell covering made up of calcium carbonate. These structures are known as coccoliths.