The Prasinophyceae are a class of green algae, which is not assigned to one of two major groups of green algae, but directly the Chloroplastida. Some species are responsible for algal blooms.


Most representatives are bean - to star-shaped flagellate protozoa. There are also unbegeißelte ( kokkoidale ) forms. They are among the smallest eukaryotic plankton species.

The cells have one, two, four or eight flagella, the start of a scourge in your pocket. The flagella beat in swimmer breast -like. The basal body - roots have a structure of x2x2 configuration. In the flagellum apparatus is multilayered structures are ( " multilayered structures", MLS), which are considered originally for the green algae. There are organic scales on the cell surface. There are up to seven per type before shed types. The outer cuticle forms a theca. The formation of dandruff occurs in the Golgi apparatus. In mitosis, the metacentric spindle collapses in telophase.

Sexual reproduction has rarely been observed, such as Nephroselmis olivacea.

The food is made by autotrophy (photosynthesis ) or Osmotrophie. Also mixotrophy happens.


The Prasinophyceae are important representatives of the marine plankton. You can make up a significant part of the plankton biomass. There are also representatives in brackish and fresh water.


The scope of the Prasinophyceae is subject to considerable changes since the group may not be monophyletic. In the following the classification by Lewis and McCourt:

  • Pyramimonadales with 87 species
  • Mamiellales with one of the smallest known eukaryotes Crustomastix three to five microns in diameter. 15 species
  • Pseudoscourfieldiales with four types

The Chlorodendrales, at Lewis and McCourt still part of the Prasinophyceae be of Adl et al. not classified here, but provided directly to the Chloroplastida.