Chlorophyta

Pediastrum duplex

The Chlorophyta are belonging to the Chloroplastida green algae. Together with the algae -like representatives of Charophyta they form the paraphyletic group of green algae.

Features

In the Chlorophyta almost all organizational levels occur: flagellated unicellular, unbranched and branched filamentous algae, leaf -like thalli, also Flechtthalli and Gewebethalli. The flagella of the motile cells are in pairs or multiples of two. A star-shaped structure at the basal body of the transition zone connecting the nine pairs of microtubules that form a scourge. The plastids have two membranes, endoplasmic reticulum but no periplastidäres. The thylakoids of plastids are available individually or stacked. As a reserve material thickness is formed within the plastids. The cells have a glycolate dehydrogenase.

The cell wall consists, if present, from cellulose. Cell division takes place without the formation of a phragmoplast.

Occurrence

The Chlorophyta live mainly in the plankton and benthos of freshwater. Some larger species occur in coastal areas of the oceans. In marine plankton they are missing almost completely. Some species live in moist places on land, epiphytic on trees, etc. Some also live symbiotically in lichens or intracellularly in animals, such as in freshwater polyps ( Hydra ).

Some representatives have secondarily lost their chloroplasts and living heterotrophic.

For occurring in the German Bight Chlorophyta see the list of marine algae of Heligoland.

System

Among the Chlorophyta encompasses the vast majority of species designated as green algae, which Charophyta are much poorer in species, as far as the algae are affected among them. After Guiry in AlgaeBase (2012 ), the Chlorophyta comprise about 4500 species. These are grouped into 12 classes:

• Subphylum Prasinophytina: Mamiellophyceae, with about 16 species
• Nephroselmidophyceae, with about 26 species
• Prasinophyceae, with about 97 species

• Chlorodendrophyceae, with about 43 species
• Chlorophyceae, with over 2300 species
• Siphonocladophyceae, with about 401 species
• Trebouxiophyceae, with about 546 species
• Ulvophyceae, with about 522 species

• Bryopsidophyceae, with about 521 species
• Dasycladophyceae, with about 50 species
• Pedinophyceae, with about 22 species
• Pleurastrophyceae, with 3 types

Some other small groups, some of which were counted among the Chlorophyta, are of Adl et al. filed directly in the Chloroplastida.