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Hacrobia Genera
The cryptomonads-haptophytes assemblage is a proposed but disputed monophyletic grouping of unicellular eukaryotes that are not included in the SAR supergroup. Several alternative names have been used for the group, including Hacrobia (derived from "ha-" referring to Haptophyta, "-cr-" referring to cryptomonads, and "-bia" as a general suffix referring to life); CCTH (standing for Cryptophyta, Centrohelida, Telonemia and Haptophyta); and "Eukaryomonadae". , it is unclear whether this group is monophyletic or not; results of phylogenetic studies are "often dependent on the selection of taxa and gene data set". Two 2012 studies produced opposite results. Members In the past, heterokonts, haptophytes, and cryptomonads have sometimes been grouped together in a group known as chromists. Though the heterokonts are now split out, Cryptophyta and Haptophyta are considered in some studies to be closely related (and are sometimes simply referred to as the "Cryptophyta+Haptophyta" grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coccolithophore
Coccolithophores, or coccolithophorids, are single-celled organisms which are part of the phytoplankton, the autotrophic (self-feeding) component of the plankton community. They form a group of about 200 species, and belong either to the kingdom Protista, according to Robert Whittaker (ecologist), Robert Whittaker's five-kingdom system, or clade Hacrobia, according to a newer biological classification system. Within the Hacrobia, the coccolithophores are in the phylum or division (botany), division Haptophyta, class Prymnesiophyceae (or Coccolithophyceae). Coccolithophores are almost exclusively Marine (ocean), marine, are photosynthesis, photosynthetic and mixotrophic, and exist in large numbers throughout the Photic zone, sunlight zone of the ocean. Coccolithophores are the most productive calcifying organisms on the planet, covering themselves with a calcium carbonate shell called a ''coccosphere''. However, the reasons they calcify remain elusive. One key function may be that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeplastida
The Archaeplastida (or kingdom Plantae '' sensu lato'' "in a broad sense"; pronounced ) are a major group of eukaryotes, comprising the photoautotrophic red algae (Rhodophyta), green algae, land plants, and the minor group glaucophytes. It also includes the non-photosynthetic lineage Rhodelphidia, a predatorial (eukaryotrophic) flagellate that is sister to the Rhodophyta, and probably the microscopic picozoans. The Archaeplastida have chloroplasts that are surrounded by two membranes, suggesting that they were acquired directly through a single endosymbiosis event by phagocytosis of a cyanobacterium. All other groups which have chloroplasts, besides the amoeboid genus '' Paulinella'', have chloroplasts surrounded by three or four membranes, suggesting they were acquired secondarily from red or green algae. Unlike red and green algae, glaucophytes have never been involved in secondary endosymbiosis events. The cells of the Archaeplastida typically lack centrioles and have mit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leucocryptea
The kathablepharids or katablepharids () are a group of heterotrophic flagellates closely related to cryptomonads. First described by Heinrich Leonhards Skuja in 1939, kathablepharids were named after the genus '' Kathablepharis''. This genus is corrected to ''Katablepharis'' under botanical nomenclature, but the original spelling is maintained under zoological nomenclature. They are single-celled protists with two anteriorly directed flagella, an anterior cytostome for ingesting eukaryotic prey, and a sheath that covers the cell membrane. They have extrusomes known as ejectisomes, as well as tubular mitochondrial cristae. Evolution Besides the known katablepharid diversity, dozens of environmental DNA sequences (both freshwater and marine) seem to represent further katablepharids which have not been cultured or formally described. Through molecular phylogenetic analyses, they are consistently recovered as the sister clade to cryptomonads, an assemblage of flagellates containing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palpitea
Palpitea is a proposed clade of eukaryotes that are related to Archaeplastida and the SAR supergroup SAR is a highly diverse clade of eukaryotes, often considered a supergroup, that includes stramenopiles (heterokonts), alveolates, and rhizarians. It is a node-based taxon (under the Sar name), including all descendants of the three groups' .... Classification Based on studies done by Cavalier-Smith, Chao & Lewis 2015 * Subphylum Palpitia Cavalier-Smith 2012 ** Class Palpitea Cavalier-Smith 2012 *** Order Palpitida **** Family Palpitomonadidae ***** Genus '' Palpitomonas'' Yabuki, Inagaki & Ishida 2010 ****** Species '' Palpitomonas bilix'' Yabuki, Inagaki & Ishida 2010 References External links Tree of Life: Hacrobia Cryptista Cryptista classes Taxa named by Thomas Cavalier-Smith Monotypic eukaryote classes {{Cryptista-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telonemea
Telonemia is a phylum of microscopic eukaryotes commonly known as telonemids. They are unicellular free-living flagellates with a unique combination of cell structures, including a highly complex cytoskeleton unseen in other eukaryotes. Telonemia shares several distinctive features with its related group, the SAR supergroup. Among these features are cortical alveoli, small sacs beneath the cell's surface that act as cushions, providing support and helping to maintain the cell's shape. Additionally, they possess tripartite mastigonemes, complex three-part hair-like structures on their flagella, the whip-like tails used for movement. These structures enhance their swimming capabilities by increasing resistance against water. Furthermore, Telonemia is equipped with filopodia, very thin, thread-like projections extending from the cell body. These projections can serve various purposes, such as aiding in movement or capturing food particles by wrapping around them. Together, the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Picomonadea
Picozoa, Picobiliphyta, Picobiliphytes, or Biliphytes are protists of a phylum of marine unicellular heterotrophic eukaryotes with a size of less than about 3 micrometers. They were formerly treated as eukaryotic algae and the smallest member of photosynthetic picoplankton before it was discovered they do not perform photosynthesis. The first species identified therein is ''Picomonas judraskeda''. They probably belong in the Archaeplastida as sister of the Rhodophyta. They were formerly placed within the cryptomonads-haptophytes assemblage. Discovery At the end of the 1990s the European project "Picodiv" clarified which organisms occur in picoplankton. In addition, for a period of two years, samples were taken in the Atlantic, in the Mediterranean, before the coast of Scotland, Alaska and Norway. Picobiliphyta were found particularly within the nutrient-poor ranges from cold coastal seas, where they can constitute up to 50 percent of the biomass. Affinities to other organisms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endohelea
Endohelea is a proposed clade of eukaryotes that are related to Archaeplastida and the SAR supergroup. They used to be considered heliozoans, but phylogenetically they belong to a group of microorganisms known as Cryptista. Classification Based on studies done by Cavalier-Smith, Chao & Lewis in 2015, the class contained two orders: Microhelida and Heliomonadida. However, according to a study by Cavalier-Smith, published in 2022, the order Heliomonadida is actually part of Cercozoa Cercozoa (now synonymised with Filosa) is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead united by phylogeny, molecular phylogenies of rRNA and actin or Ubiqu ..., and only one species of heliomonad, '' Tetrahelia pterbica'', has been kept in Endohelea as its own order Axomonadida. * Class Endohelea Cavalier-Smith 2012 ** Order Microhelida Cavalier-Smith 2011 *** Family Microheliellidae Cavalier-Smith 2011 **** ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corbihelia
Corbihelia is a proposed phylum of eukaryote The eukaryotes ( ) constitute the Domain (biology), domain of Eukaryota or Eukarya, organisms whose Cell (biology), cells have a membrane-bound cell nucleus, nucleus. All animals, plants, Fungus, fungi, seaweeds, and many unicellular organisms ...s. Classification Based on studies done by Cavalier-Smith, Chao & Lewis 2015 * Superclass Endohelia Cavalier-Smith 2015 ** Class Endohelea Cavalier-Smith 2012 *** Order Microhelida Cavalier-Smith 2011 **** Family Microheliellidae Cavalier-Smith 2011 ***** Genus '' Microheliella'' Cavalier-Smith & Chao 2012 *** Order Heliomonadida Cavalier-Smith 1993 emend. Cavalier-Smith 2012 **** Family Heliomorphidae Cavalier-Smith & Bass 2009 ***** Genus '' Heliomorpha'' Cavalier-Smith & Bass 2009 * Super Class Corbistoma Cavalier-Smith 2015 ** Class Picomonadea Seenivasan et al. 2013 Picobiliphyte.html" ;"title="iliphyta; Picobiliphyte">iliphyta; Picobiliphytes; Picozoa Seenivasan et al. 2013] ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prymnesiophyceae
Prymnesiophyceae is a haptophyte class. Although it was originally described by Casper in 1972, it did not receive a Latin diagnosis (a requirement for valid publication under the International Code of Botanical Nomenclature The ''International Code of Nomenclature for algae, fungi, and plants'' (ICN or ICNafp) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all tho ...) until Hibberd provided one in 1976. References Haptophyte classes Haptista classes {{Haptophyte-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pavlovophyceae
: Pavlovaceae is a family of haptophytes. It is the only family in the order Pavlovales, which is the only order in the class Pavlovophyceae. It contains four genera, '' Diacronema'', '' Exanthemachrysis'', ''Pavlova'' and ''Rebecca''. Pavlovophyceae haptophytes also reportedly store photosynthetic carbon in paramylon polysaccharide granules (with a crystalline microfibrillar structure), unlike the chrysolaminarin Chrysolaminarin is a linear polymer of β(1→3) and β(1→6) linked glucose units in a ratio of 11:1. It used to be known as leucosin. Function Chrysolaminarin is a storage polysaccharide typically found in photosynthetic heterokonts. It is u ... used as the polysacharide storage form by most haptophytes. References Haptophyte families Haptista families {{Haptophyte-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rappephyceae
Rappephyceae, or Rappemonads, are a small family of protists first described in 2011, of uncertain phylogenic affinity. It has been discussed as a possible member of a larger clade Haptophyta. This newly identified taxonomic class of phytoplankton are named after a professor from the Hawai’i institute of marine biology, known as Michael Rappé. Rappé discovered these phytoplankton in the Atlantic Ocean and published his findings on their DNA in 1998. Current research has shown that these organisms provide an immense amount of nutritional molecules, such as oxygen, for other organisms using biochemical processes like photosynthesis and carbon fixation. Classification Rappephyceae belong to the Haptophyte clade. The haptophytes comprise around 500 marine algal species. One of the most novel characteristics of haptophytes is their calcite, or calcium carbonate, scales that cover the cell. These are also known as coccoliths and the whole organism can be referred to as a coccol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centrohelea
The centrohelids or centroheliozoa are a large group of heliozoan protists. They include both mobile and sessile forms, found in freshwater and marine environments, especially at some depth. Characteristics Individuals are unicellular and spherical, usually around 30–80 μm in diameter, and covered with long radial axopods, narrow cellular projections that capture food and allow mobile forms to move about. A few genera have no cell covering, but most have a gelatinous coat holding scales and spines, produced in special deposition vesicles. These may be organic or siliceous and come in various shapes and sizes. For instance, in ''Raphidiophrys'' the coat extends along the bases of the axopods, covering them with curved spicules that give them a pine-treeish look, and in ''Raphidiocystis'' there are both short cup-shaped spicules and long tubular spicules that are only a little shorter than the axopods. Some other common genera include ''Heterophrys'', ''Actinocystis'', and ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
