| Ankistrodesmus | |
|---|---|
 | |
| Ankistrodesmus falcatus | |
Scientific classification  | |
| (unranked): | Viridiplantae |
| Division: | Chlorophyta |
| Class: | Chlorophyceae |
| Order: | Sphaeropleales |
| Family: | Selenastraceae |
| Genus: | Ankistrodesmus Corda |
| Species [1] | |
See text | |
Ankistrodesmus is a genus of green algae in the family Selenastraceae. [1] It is one of the most common types of phytoplankton in freshwater habitats around the world. [2]
Ankistrodesmus forms colonies of cells, usually found as loose bundles or tufts of cells. Sometimes the cells may twist around each other in the colony. Cells are many times longer than wide, and are variously needle-shaped, sickle-shaped, or sigmoid in outline. They contain a single chloroplast; the chloroplast usually contains a single pyrenoid, but may contain none or several pyrenoids. [2]
Reproduction occurs asexually; sexual reproduction is unknown in Ankistrodesmus. It exclusively forms autospores, and does not appear to have a flagellated stage in its life cycle. [3]
Some strains of Ankistrodesmus have been observed to undergo programmed cell death. The evolutionary role of this process is unknown. [4]
Ankistrodesmus is chiefly distinguished from the similar genus Monoraphidium in its habit: Ankistrodesmus forms colonies, while Monoraphidium is found as single cells. [5] Meanwhile, Selenastrum differs in having more strongly curved cells. [3] The distinctions between the genera are artificial, since they do not correspond with monophyletic groupings; [6] occasionally, Ankistrodesmus is found as single cells. [5] Other similar genera include Keratococcus and Elakatothrix . [2]
Identification of species chiefly depends on details of the size and shape of cells. [3] However, a molecular phylogenetic study has shown evidence of considerable cryptic diversity. [7]
Some strains of Ankistrodesmus are promising candidates for biodiesel production, or for producing fatty acids on a commercial scale. [8]
The Chlorophyceae are one of the classes of green algae, distinguished mainly on the basis of ultrastructural morphology. They are usually green due to the dominance of pigments chlorophyll a and chlorophyll b. The chloroplast may be discoid, plate-like, reticulate, cup-shaped, spiral- or ribbon-shaped in different species. Most of the members have one or more storage bodies called pyrenoids located in the chloroplast. Pyrenoids contain protein besides starch. Some green algae may store food in the form of oil droplets. They usually have a cell wall made up of an inner layer of cellulose and outer layer of pectose.
Sphaeropleales is an order of green algae that used to be called Chlorococcales. The order includes some of the most common freshwater planktonic algae such as Scenedesmus and Pediastrum. The Spaeropleales includes vegetatively non-motile unicellular or colonial taxa that have biflagellate zoospores with flagella that are directly opposed in direction : Sphaeroplea, Atractomorpha, Neochloris, Hydrodictyon, and Pediastrum. All of these taxa have basal body core connections.
Pandorina is a genus of green algae composed of 8, 16, or sometimes 32 cells, held together at their bases to form a sack globular colony surrounded by mucilage. The cells are ovoid or slightly narrowed at one end to appear keystone- or pear-shaped. Each cell has two flagella with two contractile vacuoles at their base, an eyespot, and a large cup-shaped chloroplast with at least one pyrenoid.
Selenastraceae is a family of green algae in the order Sphaeropleales. Members of this family are common components of the phytoplankton in freshwater habitats worldwide. A few species have been found in brackish and marine habitats, such as in the Baltic Sea.
Dictyochloris is a genus of green algae in the class Chlorophyceae. It is the sole genus of the family Dictyochloridaceae. It is commonly found in terrestrial and subaerial habitats.
Golenkinia is a genus of green algae first described in 1894 by Robert Chodat. The genus is named for the Russian phycologist Mikhail Iljitsch Golenkin. Golenkinia species live in fresh water and are found around the world.
Lagerheimia is a genus of green algae in the family Oocystaceae. It is commonly found in freshwater habitats all over the world, although some species are rare and have only been recorded from Europe or the United States.
Monoraphidium is a genus of green algae in the family Selenastraceae. Monoraphidium is found free-floating or attached to surfaces in water, or in soils. It is one of the most common types of phytoplankton in freshwater habitats, and has a cosmopolitan distribution.
Nephroselmis is a genus of green algae. It has been placed in the family Nephroselmidaceae, although a 2009 study suggests that it should be separated into its own class, Nephroselmidophyceae. One species can be an endosymbiont of Hatena arenicola.
Podohedriella is a genus of green algae in the family Selenastraceae. It is found in freshwater habitats or on damp wood.
Pseudomuriella is a genus of green algae, specifically of the class Chlorophyceae. It is the sole genus of the family Pseudomuriellaceae. It is a terrestrial alga that inhabits soils.
Raphidocelis is a genus of green algae in the family Selenastraceae. They are found in freshwater habitats.
Selenastrum is a genus of green algae in the family Selenastraceae. It is common in freshwater habitats around the world. Most species prefer temperate or warm-temperate waters.
Stauridium is a genus of green algae in the family Hydrodictyaceae. It is very common in freshwater regions throughout the world.
Trichosarcina is a genus of green algae in the order Ulotrichales. Filoprotococcus was once regarded as a synonym. However, Filoprotococcus is now considered valid in its own right. Trichosarcina is considered to be of uncertain validity.
Korshikoviella is a genus of green algae in the family Characiaceae.
Pseudokirchneriella is a genus of green algae in the family Selenastraceae. It is found as phytoplankton in freshwater ponds, lakes, and pools. It has been reported from Europe and North America.
Bracteamorpha is a genus of green algae in the order Sphaeropleales, and is the only genus in the family Bracteamorphaceae. It contains a single species, Bracteamorpha trainorii.
Chlorolobion, sometimes spelled Chlorolobium, is a genus of algae belonging to the family Selenastraceae. The species of this genus are found in freshwater habitats in Europe and America.
| Authority control databases: National |
|---|
