Selenastrum | |
---|---|
Selenastrum bibraianum | |
Scientific classification | |
(unranked): | Viridiplantae |
Division: | Chlorophyta |
Class: | Chlorophyceae |
Order: | Sphaeropleales |
Family: | Selenastraceae |
Genus: | Selenastrum Reinsch |
Type species | |
Selenastrum bibraianum Reinsch, 1866 | |
Species [1] | |
Selenastrum is a genus of green algae in the family Selenastraceae. [2] It is common in freshwater habitats around the world. [3] Most species prefer temperate or warm-temperate waters. [1]
The genus was circumscribed by the German phycologist Paul Friedrich Reinsch in 1866. [1] The name Selenastrum comes from the Greek roots selene, meaning "moon", and astron, meaning "star". [4]
Selenastrum forms colonies of cells, numbering four, eight, 16, or 32. Cells are strongly curved and crescent-shaped, with pointed ends; the cells are attached to each other on their convex sides. Each cell contains a single parietal chloroplast. [3]
Like other members of the family, Selenastrum reproduces asexually, by forming autospores. [5] Zoospores and sexual reproduction have not been observed in this genus. [1]
Selenastrum has had an unstable taxonomic history. [6] Selenastrum is distinguished from the similar and related genus Ankistrodesmus by the curvature of the cells; Selenastrum has more strongly curved cells. However, the distinction between the two genera is artificial, as shown by molecular phylogenetic data. [7] In 2016, the genera Messastrum and Curvastrum were created, differing from Selenastrum mainly in their 18S rDNA and rbcL gene sequences. Curvastrum additionally differs from Selenastrum in its colony size, forming solitary cells or colonies of up to four cells. Both genera are monotypic, containing the species Messastrum gracile (formerly Selenastrum gracile) and Curvastrum pantanale, respectively. [8]
Chlamydomonas is a genus of green algae consisting of about 150 species of unicellular flagellates, found in stagnant water and on damp soil, in freshwater, seawater, and even in snow as "snow algae". Chlamydomonas is used as a model organism for molecular biology, especially studies of flagellar motility and chloroplast dynamics, biogenesis, and genetics. One of the many striking features of Chlamydomonas is that it contains ion channels (channelrhodopsins) that are directly activated by light. Some regulatory systems of Chlamydomonas are more complex than their homologs in Gymnosperms, with evolutionarily related regulatory proteins being larger and containing additional domains.
The Trebouxiophyceae are a class of green algae, in the division Chlorophyta. Their circumscription within the green algae is not well established due to the need for more genetic studies at higher levels within the group.
The Characiosiphonaceae are a family of algae in the order Chlamydomonadales. Two genera are included in this family, Characiosiphon and Lobocharacium, each containing a single species. The genus Characiochloris may eventually be placed in this family pending future revisions, as it is phylogenetically closely related to the twose genera.
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.
Dictyosphaerium is a genus of green algae, in the family Chlorellaceae. It occurs in freshwater habitats around the world and is planktonic.
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.
Lobocharacium is a genus of green algae in the family Characiosiphonaceae. It contains the single species Lobocharacium coloradoense. It has been isolated from a pond in Colorado, United States.
Monactinus is a genus of green algae in the family Hydrodictyaceae. It is very common in freshwater regions throughout the world.
Parapediastrum is a genus of green algae in the family Hydrodictyaceae. It is fairly common in freshwater regions throughout the world.
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.
Pseudopediastrum is a genus of green algae in the family Hydrodictyaceae. It is very common in freshwater regions throughout the world.
Raphidocelis is a genus of green algae in the family Selenastraceae. They are found in freshwater habitats.
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.
The Klebsormidiaceae are a family containing five genera of charophyte green alga forming multicellular, non-branching filaments. The genus Chlorokybus was previously included as well, but this problematic and poorly known genus is now placed in a separate class Chlorokybophyceae.
Batrachospermaceae is a family of fresh water red algae (Rhodophyta). Genera within the Batrachospermaceae generally have a "Lemanea-type" life history with carpospores germinating to produce chantransia. Sporophyte phase with meiosis occurs in an apical cell to produce the gametophyte stage. Pit connections have two pit plug cap layers with the other layer enlarged. This family of freshwater red algae is uniaxial, meaning each filament with a single apical cell. The genera included within Batrachospermaceae are listed in the table below.
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.