Prasiolales | |
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Prasiola stipitata | |
Scientific classification ![]() | |
Clade: | Viridiplantae |
Division: | Chlorophyta |
Class: | Trebouxiophyceae |
Order: | Prasiolales F.E.Fritsch |
Families [1] | |
Prasiolales is an order of green algae in the class Trebouxiophyceae. [2] Members of this order are ecologically widespread and are found in freshwater, marine, and terrestrial habitats from the Arctic to the Antarctic. [3]
Morphological features include a single stellate, axial chloroplast with a central pyrenoid. [4] The ultrastructure of Prasiolales is unique and includes cells with four flagella, with their basal flagellar apparatuses in a counterclockwise orientation. [4] [5] For a long time, its placement was uncertain and debated between Ulvophyceae and Trebouxiophyceae (also known as Pleurastrophyceae). Molecular data, however, have robustly supported its placement in the latter class. [3]
Traditionally the order contained a single family, Prasiolaceae. Molecular phylogenetics studies have found that coccoid algae of very simple morphology, such as Stichococcus , also belong to this order. [6]
Genera of uncertain placement to family include: [1]
Molecular phylogenetic studies have shown the following relationships (not all genera are included): [7] [8] [9] [10] [6]
Prasiolales |
| Koliellaceae pro parte | ||||||||||||||||||||||||||||||||||||
Chlorophyta is a division of green algae informally called chlorophytes.
Chlamydomonadales, also known as Volvocales, are an order of flagellated or pseudociliated green algae, specifically of the Chlorophyceae. Chlamydomonadales can form planar or spherical colonies. These vary from Gonium up to Volvox. Each cell has two flagella, and is similar in appearance to Chlamydomonas, with the flagella throughout the colony moving in coordination.
Prasiola is a genus of macroscopic green algae, found in a variety of habitats ranging from terrestrial, freshwater, to marine. The genus has a cosmopolitan distribution, ranging from the Arctic to the Antarctic.
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 Sphaeropleales includes vegetatively non-motile unicellular, colonial, or filamentous taxa. They 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. Motile cells generally lack cell walls or have only a very fine layer surrounding the cell membrane. Other common characteristics include a robust vegetative cell wall, cup-shaped chloroplasts with large pyrenoids, and relatively large nuclei.
The Trebouxiophyceae, also known as trebouxiophytes, are a class of green algae, in the division Chlorophyta. Members of this class are single-celled, colonial, or multicellular and are found in freshwater or terrestrial habitats worldwide. Many taxa in the Trebouxiophyceae form symbiotic relationships with other organisms; in particular, the majority of phycobionts within lichens are trebouxiophytes. A number of taxa have also lost the ability to photosynthesize, and have evolved to become parasitic; examples include Prototheca and Helicosporidium.
Botryococcaceae is a family of green algae in the class Trebouxiophyceae.
Prasiolaceae is a family of green algae in the order Prasiolales. Members of this family are found in freshwater, terrestrial, and marine habitats.
Sphaeropleaceae is a family of green algae in the order Sphaeropleales.
Choricystis is a genus of green algae in the class Trebouxiophyceae, considered a characteristic picophytoplankton in freshwater ecosystems. Choricystis, especially the type species Choricystis minor, has been proposed as an effective source of fatty acids for biofuels. Choricystis algacultures have been shown to survive on wastewater. In particular, Choricystis has been proposed as a biological water treatment system for industrial waste produced by the processing of dairy goods.
Dictyosphaerium is a genus of green algae, in the family Chlorellaceae. It occurs in freshwater habitats around the world and is planktonic. The name comes from the Greek roots diktyon, meaning "net", and sphaira, meaning "ball", referring to its morphology.
Koliella is a genus of green algae in the order Prasiolales. Members of this genus are found in freshwater plankton, but some are also found on snow and ice.
Micractinium is a genus of green algae in the family Chlorellaceae. Species of the genus Micractinium are common in freshwater habitats. A few species are found as endosymbionts of protozoa, such as Micractinium conductrix and Micractinium tetrahymenae.
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.
Pseudochlorella is a genus of green algae in the family Koliellaceae.
Rosenvingiella is a genus of green algae in the family Prasiolaceae. Members of this genus are found in marine or terrestrial habitats.
Symbiochloris reticulata is a species of green alga in the Trebouxiales. It is a known as a photobiont with several lichen species, like Lobaria pulmonaria, but also as a free-living soil alga as well. Phylogenetic analysis of rRNA sequence data revealed that the species shares a sister group relationship with two other green algae that lack motile stages, Chlorella saccharophila and C. luteoviridis.
Raphidonema is a genus of filamentous green alga comprising five species. It is a member of the Trebouxiophyceae.
Trebouxiaceae is a family of green algae in the order Trebouxiales. Many species of Trebouxiaceae are found as symbionts associated with terrestrial lichens, although some genera are also found free-living.
Koliellaceae is a family of green algae in the order Prasiolales.
Asterochloris is a genus of green algae in the family Trebouxiophyceae. It is a common photobiont in lichen, occurring in the thalli of more than 20 lichen genera worldwide. Asterochloris is distinguishable from the morphologically similar genus Trebouxia, primarily due to its deeply lobed chloroplast, the placement of the chloroplast along the cell's periphery before the initiation of zoospore or aplanospore formation, and its tendency to primarily reproduce asexually through the production of aplanospores.