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16-419: Conventionally, many groups of coccoid green algae were lumped in the order Chlorococcales sensu lato by Komárek & Fott (1983), based on Pascher's (1918) idea of establishing orders according to life forms. However, coccoid green algae are currently placed in several orders of Chlorophyceae , Trebouxiophyceae , Ulvophyceae (e.g., Chlorocystis ) and Prasinophyceae within the division Chlorophyta , or in

32-439: A cell wall made up of an inner layer of cellulose and outer layer of pectose . Depending on the species, Chlorophyceae can grow unicellular (e.g. Chlamydomonas ) , colonial (e.g. Volvox ), filamentous (e.g. Ulothrix ), or multicellular. They are usually green due to the presence of chlorophyll a and chlorophyll b ; they can also contain the pigment beta-carotene . There are two clades of Chlorophyceae as defined by

48-594: A starch sheath) that are localised around the chloroplast. Some algae may also store food in the form of oil droplets. The inner cell wall layer is made of cellulose and the outer layer of pectose. Chlorophyceae can reproduce both asexually and sexually. Vegetative reproduction usually takes place by fragmentation. Asexual reproduction is by flagellated zoospores . And haplospore, perennation (akinate and palmella stage). Asexual reproduction by mitospore absent in spyrogyra. Also by aplanospores, hypnospores, Palmella stage, etc. Sexual reproduction shows considerable variation in

64-563: Is hosted at the National University of Ireland 's Ryan Institute, in Galway . It includes about all types of algae, as well as one group of flowering plants , the sea-grasses . Information about each species' taxonomy , nomenclature and distribution is included, and the algae covered include terrestrial as well as marine and freshwater species, such as seaweeds , phytoplankton , and freshwater algae. As of 2019 , marine species have

80-772: The Flanders Marine Institute (VLIZ) signed an end-user license agreement regarding the Electronic Intellectual Property of AlgaeBase. This allows the World Register of Marine Species (WoRMS) to include taxonomic names of algae in WoRMS, thereby allowing WoRMS, as part of the Aphia database , to make its overview of all described marine species more complete. Synchronisation of the AlgaeBase data with Aphia and WoRMS

96-806: The Ryan Institute and the Environmental Change Institute, as well as by Atlantic Philanthropies , and the European Union . The synchronisation between AlgaeBase and Aphia was possible through support of the LifeWatch Species Information Backbone. LifeWatch , the E-Science European Infrastructure for Biodiversity and Ecosystem Research, is a distributed virtual laboratory , which is used for different aspects of biodiversity research. As of 2022 ,

112-585: The arrangement of their flagella , called CW and DO. Members of the CW clade have flagella that are displaced in a "clockwise" (CW, 1–7 o'clock) direction e.g. Chlamydomonadales . Members of the DO clade have flagella that are "directly opposed" (DO, 12–6 o'clock) e.g. Sphaeropleales . The chloroplast may be discoid, cup-shaped (e.g. Chlamydomonas ), spiral or ribbon shaped. Most chlorophytes have one or more storage bodies called pyrenoids (central proteinaceous body covered with

128-575: The best coverage, including sea-grasses. As of 2014 there were nearly 17,000 images, and the database was being used by 2,000–3,000 individual visitors each day. As of 2023, there were about 170,000 species and infraspecies in AlgaeBase. The compilation of the data was funded by the Irish Government Department of Education and Science's Programme for Research in Third-level Institutions ( PRTLI ) 2, 3 and 4 programmes, to

144-611: The concept of the life cycle of Chlorella, which at present is considered to be strictly asexual in character. Asexual reproduction in Chlorella ellipsoides has been studied in detail and the following four phases have been observed during the asexual reproduction. As of May 2023 , AlgaeBase accepted the following orders in the class Chlorophyceae: Along with these genera, AlgaeBase recognizes several taxa that are incertae sedis (i.e. unplaced to an order): Other orders that have been recognized include: In older classifications,

160-439: The division Charophyta (e.g., Chlorokybales , Desmidiales ). According to Komárek & Fott (1983): According to Smith (1938) : This Chlorophyceae -related article is a stub . You can help Misplaced Pages by expanding it . Chlorophyceae See text . The Chlorophyceae are one of the classes of green algae , distinguished mainly on the basis of ultrastructural morphology. They are usually green due to

176-407: 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

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192-405: The presence of phytochromes, flavonoids, and the chemical precursors to the cuticle. The sole method of reproduction in Chlorella is asexual and azoosporic. The content of the cell divides into 2,4 (B), 8(C) sometimes daughter protoplasts. Each daughter protoplast rounds off to form a non-motile spore. These autospores (spores having the same distinctive shape as the parent cell) are liberated by

208-549: The rupture of the parent cell wall (D). On release each autospore grows to become a new individual. The presence of sulphur in the culture medium is considered essential for cell division. It takes place even in the dark with sulphur alone as the source material but under light conditions nitrogen also required in addition. Pearsall and Loose (1937) reported the occurrence of motile cells in Chlorella . Bendix (1964) also observed that Chlorella produces motile cells which might be gametes. These observations have an important bearing on

224-555: The term Chlorophyceae is sometimes used to apply to all the green algae except the Charales , and the internal division is considerably different. AlgaeBase AlgaeBase is a global species database of information on all groups of algae , both marine and freshwater , as well as sea-grass . AlgaeBase began in March 1996, founded by Michael Guiry . By 2005, the database contained about 65,000 names. In 2013, AlgaeBase and

240-409: The type and formation of sex cells and it may be isogamous e.g. Chlamydomonas, Ulothrix , anisogamous e.g. Chlamydomonas, Eudorina or Oogamous e.g. Chlamydomonas, Volvox . Chlamydomonas has all three types of sexual reproduction. They share many similarities with the higher plants, including the presence of asymmetrical flagellated cells, the breakdown of the nuclear envelope at mitosis, and

256-520: Was undertaken manually until March 2015, but this was very time-consuming, so an online application was developed to semi-automate the synchronisation, launching in 2015 in conjunction with Michael Guiry and the chief programmer of AlgaeBase, Pier Kuipers. After a long phase of further development and testing, the AlgaeBase harvester tool was implemented by the WoRMS data management team in early 2019. Since then, newly-added species in AlgaeBase are added to Aphia and, if marine, to WoRMS as well. The database

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