| Dictyosphaerium | |
|---|---|
 | |
Scientific classification  | |
| (unranked): | Viridiplantae |
| Division: | Chlorophyta |
| Class: | Trebouxiophyceae |
| Order: | Chlorellales |
| Family: | Chlorellaceae |
| Genus: | Dictyosphaerium Nägeli, 1849 |
| Type species | |
| Dictyosphaerium chlorelloides | |
| Species [1] | |
Dictyosphaerium is a genus of green algae, in the family Chlorellaceae. [1] It occurs in freshwater habitats around the world and is planktonic. [1] [2]
Dictyosphaerium consists of irregular colonies of 4 to 64 cells in a common mucilaginous envelope 10–100 μm wide. Cells are roughly spherical to ellipsoidal, 1-10 μm in diameter, with one nucleus and a single pyrenoid-containing chloroplast. Cells are attached to the end of thin stalks; the stalks emerge from the center of the colony and continuously branch out. [1] These stalks are formed from the remnants of the mother cell wall. [2]
Dictyosphaerium cells reproduce asexually by autospores. Two or four autospores are produced per sporangium; after release, the mother cell wall gelatinizes and develops into a thin strand, which are connected to the newly released cells. [2]
Dictyosphaerium has traditionally been classified in its own family, Dictyosphaeriaceae, [3] or as part of the family Botryococcaceae, characterized by cells connected by gelatinous stalks or strands of mucilage. [4] However, molecular phylogenetic studies have demonstrated that Dictyosphaerium is closely related to the unicellular genus Chlorella , and is now currently placed in the family Chlorellaceae. [1]
Additionally, the morphotype of Dictyosphaerium (consisting of branching strands of mucilage connecting cells) is known to be polyphyletic, having evolved multiple times. Therefore, this morphotype can now be found in many new genera. For example, the genus Mucidosphaerium differs from Dictyosphaeriumsensu stricto in having spherical cells, as opposed to Dictyosphaerium with oval cells. [5] The genus Mychonastes (including the former genus Pseudodictyosphaerium) differs in having chloroplasts without pyrenoids, and more irregular mucilaginous strands. [6]
Other similar genera include Compactochlorella , Kalenjinia , Marasphaerium , Masaia , [2] Hindakia , Heynigia , [7] and Xerochlorella . [8] These genera appear to be more or less cryptic, being reliably differentiated only by DNA barcoding. [9] Their biogeographical patterns remain unclear. [10]
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.
Neochloridaceae is a family of green algae in the order Sphaeropleales.
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.
Ankistrodesmus is a genus of green algae in the family Selenastraceae. It is one of the most common types of phytoplankton in freshwater habitats around the world.
Ankyra is a genus of green algae in the family Characiaceae. This genus of algae is closely related to Atractomorpha and Sphaeroplea. They are found in stagnant waters.
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.
Dimorphococcus is a genus of fresh water green algae in the family Scenedesmaceae. It is found as a component of the phytoplankton of freshwater ponds, lakes, and peat bogs. It is widespread, but usually not very common.
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.
Mychonastes is a genus of green algae, specifically of the Chlorophyceae. It is the sole genus of the family Mychonastaceae.
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.
Tetraedron is a genus of green algae in the family Hydrodictyaceae. It may also be spelled as Tetraëdron.
Tetrastrum is a genus of green algae (Chlorophyta). It is a common component of the phytoplankton of freshwater habitats, particularly eutrophic and alkaline waters.
Chlorella volutis is a species of euryhaline, unicellular microalga in the Division Chlorophyta. It is spherical to oval-shaped, is solitary and lacks a mucilaginous envelope.
Chlorella rotunda is a euryhaline, unicellular microalga in the Division Chlorophyta. It is spherical to oval-shaped, is solitary and lacks a mucilaginous envelope.
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.
Elongatocystis is an autotrophic green alga in the Oocystaceae family that is defined by its elongated type cell. This genus was discovered in a rockpool at Belvedere River, Mpumalanga, South Africa and described by Krienitz and Bock in 2011 along with two other strains of Oocystaceae. Its discovery and genetic analysis determined that Oocystis ecballocystiformis should be removed. In its place, the genus Elongatocystis was proposed to more accurately represent the phylogenetic tree.