Class of microalgae, found in the oceans, waterways and soils of the world
For a molecule of two atoms, see Diatomic molecule.
Diatom
Temporal range: Jurassic–Present
PreꞒ
Ꞓ
O
S
D
C
P
T
J
K
Pg
N
Light microscopy of a sampling of marine diatoms found living between crystals of annual sea ice in Antarctica, showing a multiplicity of sizes and shapes
Scientific classification
Domain:
Eukaryota
Clade:
Diaphoretickes
Clade:
SAR
Clade:
Stramenopiles
Phylum:
Gyrista
Subphylum:
Ochrophytina
Infraphylum:
Diatomista
Class:
Bacillariophyceae Dangeard, 1933[1]
Subclasses[2]
Bacillariophycidae
Coscinodiscophycidae
Fragilariophycidae
Synonyms
Diatomea Dumortier, 1821[3]
Diatomophyceae Rabenhorst, 1864[4]
Bacillariae Haeckel, 1878[5]
Bacillariophyta Engler & Gilg, 1919[6]
A diatom (Neo-Latin diatoma)[a] is any member of a large group comprising several genera of algae, specifically microalgae, found in the oceans, waterways and soils of the world. Living diatoms make up a significant portion of the Earth's biomass: they generate about 20 to 50 percent of the oxygen produced on the planet each year,[11][12] take in over 6.7 billion tonnes of silicon each year from the waters in which they live,[13] and constitute nearly half of the organic material found in the oceans. The shells of dead diatoms can reach as much as a half-mile (800 m) deep on the ocean floor, and the entire Amazon basin is fertilized annually by 27 million tons of diatom shell dust transported by transatlantic winds from the African Sahara, much of it from the Bodélé Depression, which was once made up of a system of fresh-water lakes.[14][15]
Diatoms are unicellular organisms: they occur either as solitary cells or in colonies, which can take the shape of ribbons, fans, zigzags, or stars. Individual cells range in size from 2 to 200 micrometers.[16] In the presence of adequate nutrients and sunlight, an assemblage of living diatoms doubles approximately every 24 hours by asexual multiple fission; the maximum life span of individual cells is about six days.[17] Diatoms have two distinct shapes: a few (centric diatoms) are radially symmetric, while most (pennate diatoms) are broadly bilaterally symmetric.
The unique feature of diatoms are that they are surrounded by a cell wall made of silica (hydrated silicon dioxide), called a frustule.[18] These frustules produce structural coloration, prompting them to be described as "jewels of the sea" and "living opals".
Movement in diatoms primarily occurs passively as a result of both ocean currents and wind-induced water turbulence; however, male gametes of centric diatoms have flagella, permitting active movement to seek female gametes. Similar to plants, diatoms convert light energy to chemical energy by photosynthesis, but their chloroplasts were acquired in different ways.[19]
Unusually for autotrophic organisms, diatoms possess a urea cycle, a feature that they share with animals, although this cycle is used to different metabolic ends in diatoms. The family Rhopalodiaceae also possess a cyanobacterial endosymbiont called a spheroid body. This endosymbiont has lost its photosynthetic properties, but has kept its ability to perform nitrogen fixation, allowing the diatom to fix atmospheric nitrogen.[20] Other diatoms in symbiosis with nitrogen-fixing cyanobacteria are among the genera Hemiaulus, Rhizosolenia and Chaetoceros.[21]
Dinotoms are diatoms that have become endosymbionts inside dinoflagellates. Research on the dinoflagellates Durinskia baltica and Glenodinium foliaceum have shown that the endosymbiont event happened so recently, evolutionarily speaking, that their organelles and genome are still intact with minimal to no gene loss. The main difference between these and free living diatoms is that they have lost their cell wall of silica, making them the only known shell-less diatoms.[22]
The study of diatoms is a branch of phycology. Diatoms are classified as eukaryotes, organisms with a nuclear envelope-bound cell nucleus, that separates them from the prokaryotes archaea and bacteria. Diatoms are a type of plankton called phytoplankton, the most common of the plankton types. Diatoms also grow attached to benthic substrates, floating debris, and on macrophytes. They comprise an integral component of the periphyton community.[23] Another classification divides plankton into eight types based on size: in this scheme, diatoms are classed as microalgae. Several systems for classifying the individual diatom species exist.
Fossil evidence suggests that diatoms originated during or before the early Jurassic period, which was about 150 to 200 million years ago. The oldest fossil evidence for diatoms is a specimen of extant genus Hemiaulus in Late Jurassic aged amber from Thailand.[24]
Diatoms are used to monitor past and present environmental conditions, and are commonly used in studies of water quality. Diatomaceous earth (diatomite) is a collection of diatom shells found in the Earth's crust. They are soft, silica-containing sedimentary rocks which are easily crumbled into a fine powder and typically have a particle size of 10 to 200 μm. Diatomaceous earth is used for a variety of purposes including for water filtration, as a mild abrasive, in cat litter, and as a dynamite stabilizer.
^Dangeard, P. (1933). Traite d'Algologie. Paul Lechvalier and Fils, Paris, [1] Archived 4 October 2015 at the Wayback Machine.
^"Bacillariophyceae". WoRMS. World Register of Marine Species. 2024. Retrieved 9 May 2024.
^Dumortier, B.-C. (1822). Commentationes botanicae. Observations botaniques, dédiées à la Société d'Horticulture de Tournay(PDF). Tournay: Imprimerie de Ch. Casterman-Dieu, Rue de pont No. 10. pp. [i], [1]-116, [1, tabl., err.] Archived from the original (PDF) on 6 October 2015 – via Algaebase.
^Rabenhorst, L. Flora europaea algarum aquae dulcis et submarinae (1864–1868). Sectio I. Algas diatomaceas complectens, cum figuris generum omnium xylographice impressis (1864). pp. 1–359. Lipsiae [Leipzig]: Apud Eduardum Kummerum.
^Haeckel, E. (1878). Das Protistenreich Archived 10 November 2014 at the Wayback Machine.
^Engler, A. & Gilg, E. (1919). Syllabus der Pflanzenfamilien: eine Übersicht über das gesamte Pflanzensystem mit besonderer Berücksichtigung der Medizinal- und Nutzpflanzen, nebst einer Übersicht über die Florenreiche und Florengebiete der Erde zum Gebrauch bei Vorlesungen und Studien über spezielle und medizinisch-pharmazeutische Botanik, 8th ed., Gebrüder Borntraeger Verlag, Berlin, 395 p.
^διατομή. Liddell, Henry George; Scott, Robert; A Greek–English Lexicon at the Perseus Project
^διάτομος. Liddell, Henry George; Scott, Robert; A Greek–English Lexicon at the Perseus Project
^διατέμνω. Liddell, Henry George; Scott, Robert; A Greek–English Lexicon at the Perseus Project
^The Compact Oxford English Dictionary. Clarendon Press. 1971. ISBN 0918414083.
^"The Air You're Breathing? A Diatom Made That". Live Science. 11 June 2014. Archived from the original on 30 April 2018. Retrieved 30 April 2018.
^"What are Diatoms?". Diatoms of North America. Archived from the original on 25 January 2020. Retrieved 28 January 2020.
^Treguer, P.; Nelson, D. M.; Van Bennekom, A. J.; Demaster, D. J.; Leynaert, A.; Queguiner, B. (1995). "The Silica Balance in the World Ocean: A Reestimate". Science. 268 (5209): 375–9. Bibcode:1995Sci...268..375T. doi:10.1126/science.268.5209.375. PMID 17746543. S2CID 5672525.
^"King's College London – Lake Megachad". www.kcl.ac.uk. Archived from the original on 27 November 2018. Retrieved 5 May 2018.
^Bristow, C.S.; Hudson-Edwards, K.A.; Chappell, A. (2010). "Fertilizing the Amazon and equatorial Atlantic with West African dust". Geophys. Res. Lett. 37 (14): L14807. Bibcode:2010GeoRL..3714807B. doi:10.1029/2010GL043486. S2CID 128466273.
^Cite error: The named reference HasleSyvertsen1996 was invoked but never defined (see the help page).
^"Gas Guzzlers". Archived from the original on 22 May 2018. Retrieved 22 May 2018.
^"More on Diatoms". University of California Museum of Paleontology. Archived from the original on 4 October 2012. Retrieved 20 May 2015.
^van den Hoek, C.; Mann, D.G.; Jahns, H.M. (1995). Algae: an introduction to Phycology. Cambridge: Cambridge University Press. pp. 165–218. ISBN 978-0-521-31687-3.
^Nakayama, T.; Kamikawa, R.; Tanifuji, G.; Kashiyama, Y.; Ohkouchi, N.; Archibald, J. M.; Inagaki, Y. (2014). "Complete genome of a nonphotosynthetic cyanobacterium in a diatom reveals recent adaptations to an intracellular lifestyle". Proceedings of the National Academy of Sciences of the United States of America. 111 (31): 11407–11412. Bibcode:2014PNAS..11111407N. doi:10.1073/pnas.1405222111. PMC 4128115. PMID 25049384.
^Pierella Karlusich, Juan José; Pelletier, Eric; Lombard, Fabien; Carsique, Madeline; Dvorak, Etienne; Colin, Sébastien; Picheral, Marc; Cornejo-Castillo, Francisco M.; Acinas, Silvia G.; Pepperkok, Rainer; Karsenti, Eric (6 July 2021). "Global distribution patterns of marine nitrogen-fixers by imaging and molecular methods". Nature Communications. 12 (1): 4160. Bibcode:2021NatCo..12.4160P. doi:10.1038/s41467-021-24299-y. ISSN 2041-1723. PMC 8260585. PMID 34230473.
^Functional Relationship between a Dinoflagellate Host and Its Diatom Endosymbiont | Molecular Biology and Evolution | Oxford Academic
^Wehr, J. D.; Sheath, R. G.; Kociolek, J. P., eds. (2015). Freshwater Algae of North America: Ecology and Classification (2nd ed.). San Diego: Academic Press. ISBN 978-0-12-385876-4.
^Girard, Vincent; Saint Martin, Simona; Buffetaut, Eric; Saint Martin, Jean-Paul; Néraudeau, Didier; Peyrot, Daniel; Roghi, Guido; Ragazzi, Eugenio; Suteethorn, Varavudh (2020). "Thai amber: insights into early diatom history?". BSGF - Earth Sciences Bulletin. 191: 23. doi:10.1051/bsgf/2020028. ISSN 1777-5817.
^The Inner Space of the Subarctic Pacific Ocean Archived 27 October 2020 at the Wayback Machine NASA Earth Expeditions, 4 September 2018. This article incorporates text from this source, which is in the public domain.
^Rousseaux, Cecile S.; Gregg, Watson W. (2015). "Recent decadal trends in global phytoplankton composition". Global Biogeochemical Cycles. 29 (10): 1674–1688. Bibcode:2015GBioC..29.1674R. doi:10.1002/2015GB005139.
^Colin, S., Coelho, L.P., Sunagawa, S., Bowler, C., Karsenti, E., Bork, P., Pepperkok, R. and De Vargas, C. (2017) "Quantitative 3D-imaging for cell biology and ecology of environmental microbial eukaryotes". eLife, 6: e26066. doi:10.7554/eLife.26066.002. Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License Archived 16 October 2017 at the Wayback Machine.
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A diatom (Neo-Latin diatoma) is any member of a large group comprising several genera of algae, specifically microalgae, found in the oceans, waterways...
Diatomic molecules (from Greek di- 'two') are molecules composed of only two atoms, of the same or different chemical elements. If a diatomic molecule...
layer of fossilized remains of microscopic water organism called diatoms. These diatoms are mined from diatomite deposits which are located along the Earth's...
5–2% iron oxide. Diatomaceous earth consists of the fossilized remains of diatoms, a type of hard-shelled microalgae. It is used as a filtration aid, mild...
Diatomic carbon (systematically named dicarbon and 1λ2,2λ2-ethene), is a green, gaseous inorganic chemical with the chemical formula C=C (also written...
Brechites is a genus of bivalves belonging to the family Penicillidae. The species of this genus are found in Red Sea, Malesia and Australia. Species:...
Diatoms belong to a large group called the heterokonts, which include both autotrophs such as golden algae and kelp; and heterotrophs such as water moulds...
Horizontal gene transmission within Diatom viruses occurs when a Diatom virus infects a Diatom and then spreads to other Diatoms via direct contact or through...
A frustule is the hard and porous cell wall or external layer of diatoms. The frustule is composed almost purely of silica, made from silicic acid, and...
element bind to form dioxygen, a colorless and odorless diatomic gas with the formula O 2. Diatomic oxygen gas currently constitutes 20.95% of the Earth's...
kills, cyanobacteria Microcystis aeruginosa can make poisonous toxins, and diatom Chaetoceros convolutus can damage fish gills. Rivers, such as the Amazon...
redistributed among the orbitals. This tool is very well suited for simple diatomic molecules such as dihydrogen, dioxygen, and carbon monoxide but becomes...
class(s) of diatoms. They are similar to the Centrales, a traditional, paraphyletic subdivision of the heterokont algae known as diatoms. The order is...
for this aim in different algal groups. Diatom DNA barcoding is a method for taxonomical identification of diatoms even to species level. It is conducted...
blooms, with diatom bloom frequency increasing by a factor of 2.5 and non-diatom bloom frequency increasing by a factor of 6. The non-diatoms, such as the...
role of protist shells depends on the type of protist. Protists such as diatoms and radiolaria have intricate, glass-like shells made of silica that are...
capacity at constant volume, approximately 3/2 for a monatomic gas, 5/2 for diatomic gas, and 3 for non-linear molecules if we treat translations and rotations...
heterokont algae known as diatoms. The order is named for the shape of the cell walls (or valves or frustules) of pennate diatoms, which are elongated in...
Phaeodactylum tricornutum is a diatom. Unlike other diatoms, P. tricornutum can exist in different morphotypes (fusiform, triradiate, and oval) and changes...
free-living organisms as well as symbionts within potentially up to 13 diatoms distributed throughout the global ocean. As a symbiont, Richelia can associate...
presence of diatoms in crime scene samples and victims. Different methods are used to collect this data but all identify the ratios of different diatom colonies...