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87-455: Pandoravirus is a proposed genus of giant virus , first discovered in 2013. It is the third largest in physical size of any known viral genus, behind Pithovirus and Megaklothovirus . Pandoraviruses have double stranded DNA genomes, with the largest genome size (2.5 million base pairs) of any known viral genus. The discovery of Pandoraviruses by a team of French scientists, led by husband and wife Jean-Michel Claverie and Chantal Abergel,

174-557: A species : see Botanical name and Specific name (zoology) . The rules for the scientific names of organisms are laid down in the nomenclature codes , which allow each species a single unique name that, for animals (including protists ), plants (also including algae and fungi ) and prokaryotes ( bacteria and archaea ), is Latin and binomial in form; this contrasts with common or vernacular names , which are non-standardized, can be non-unique, and typically also vary by country and language of usage. Except for viruses ,

261-436: A top-down or bottom-up approach . Essentially, this research is focused on understanding whether changes in the food web are driven by nutrients at the bottom of the food web or predators at the top. The general conclusion is that the bottom-up approach seemed to be more predictive of food web behavior. This indicates that plankton have more sway in determining the success of the primary consumer species that prey on them than do

348-436: A viral replication cycle . They lack the ability to make their own proteins, rely on the host cells for ATP (energy) and replication, and also do not contain ribosomes or produce energy to divide. Under the microscope, scientists observed the virus enter the amoeba through fusion with membrane vacuoles, and integrate their DNA into the host cells. The host cell replicates the viral particles and eventually splits open, releasing

435-715: A 1.9 megabase genome. Pandoraviruses are oval in shape and are about 1  micrometer  (1000 nanometers) in length. Other viruses range from 25 to 100 nanometers. In addition to being large physically, Pandoraviruses have a large genome made up of 2,500 genes, compared to only 10 genes on average in other viruses. For example, the Influenza A virus contains 7 genes and HIV contains only 9 genes. Gene content varies among species of Pandoravirus, with Pandoravirus salinus containing 2,500 genes and Pandoravirus dulcis containing about 1,500 genes. Pandoraviruses were originally mistaken for bacteria ; however, they lack some of

522-432: A buffer that prevents the collapse of ecosystems during times with little to no light. Plankton are also often described in terms of size. Usually the following divisions are used:  However, some of these terms may be used with very different boundaries, especially on the larger end. The existence and importance of nano- and even smaller plankton was only discovered during the 1980s, but they are thought to make up

609-475: A few months, famously can enter suspended animation during dry or hostile conditions and survive for decades. This allows them to be ubiquitous in terrestrial environments despite needing water to grow and reproduce. Many microscopic crustacean groups like copepods and amphipods (of which sandhoppers are members) and seed shrimp are known to go dormant when dry and live in transient bodies of water too Gelatinous zooplankton are fragile animals that live in

696-651: A later homonym of a validly published name is a nomen illegitimum or nom. illeg. ; for a full list refer to the International Code of Nomenclature for algae, fungi, and plants and the work cited above by Hawksworth, 2010. In place of the "valid taxon" in zoology, the nearest equivalent in botany is " correct name " or "current name" which can, again, differ or change with alternative taxonomic treatments or new information that results in previously accepted genera being combined or split. Prokaryote and virus codes of nomenclature also exist which serve as

783-628: A long time and redescribed as new by a range of subsequent workers, or if a range of genera previously considered separate taxa have subsequently been consolidated into one. For example, the World Register of Marine Species presently lists 8 genus-level synonyms for the sperm whale genus Physeter Linnaeus, 1758, and 13 for the bivalve genus Pecten O.F. Müller, 1776. Within the same kingdom, one generic name can apply to one genus only. However, many names have been assigned (usually unintentionally) to two or more different genera. For example,

870-418: A newly defined genus should fulfill these three criteria to be descriptively useful: Moreover, genera should be composed of phylogenetic units of the same kind as other (analogous) genera. The term "genus" comes from Latin genus , a noun form cognate with gignere ('to bear; to give birth to'). The Swedish taxonomist Carl Linnaeus popularized its use in his 1753 Species Plantarum , but

957-430: A planktonic individual is referred to as a plankter. The adjective planktonic is widely used in both the scientific and popular literature, and is a generally accepted term. However, from the standpoint of prescriptive grammar, the less-commonly used planktic is more strictly the correct adjective. When deriving English words from their Greek or Latin roots, the gender-specific ending (in this case, "-on" which indicates

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1044-421: A process known as volatilisation . When airborne, these microbes can be transported long distances to coastal regions. If they hit land they can have an effect on animal, vegetation and human health. Marine aerosols that contain viruses can travel hundreds of kilometers from their source and remain in liquid form as long as the humidity is high enough (over 70%). These aerosols are able to remain suspended in

1131-415: A process which depends on typically inadequate zooplankton density, starving many larvae. In time fish larvae become able to swim against currents, at which point they cease to be plankton and become juvenile fish . Holoplankton are organisms that are planktic for their entire life cycle. Holoplankton can be contrasted with meroplankton , which are planktic organisms that spend part of their life cycle in

1218-497: A reduced level (because of reduced light). Despite significant macronutrient concentrations, some ocean regions are unproductive (so-called HNLC regions ). The micronutrient iron is deficient in these regions, and adding it can lead to the formation of phytoplankton algal blooms . Iron primarily reaches the ocean through the deposition of dust on the sea surface. Paradoxically, oceanic areas adjacent to unproductive, arid land thus typically have abundant phytoplankton (e.g.,

1305-409: A reference for designating currently accepted genus names as opposed to others which may be either reduced to synonymy, or, in the case of prokaryotes, relegated to a status of "names without standing in prokaryotic nomenclature". An available (zoological) or validly published (botanical) name that has been historically applied to a genus but is not regarded as the accepted (current/valid) name for

1392-427: A taxon; however, the names published in suppressed works are made unavailable via the relevant Opinion dealing with the work in question. In botany, similar concepts exist but with different labels. The botanical equivalent of zoology's "available name" is a validly published name . An invalidly published name is a nomen invalidum or nom. inval. ; a rejected name is a nomen rejiciendum or nom. rej. ;

1479-455: A total of c. 520,000 published names (including synonyms) as at end 2019, increasing at some 2,500 published generic names per year. "Official" registers of taxon names at all ranks, including genera, exist for a few groups only such as viruses and prokaryotes, while for others there are compendia with no "official" standing such as Index Fungorum for fungi, Index Nominum Algarum and AlgaeBase for algae, Index Nominum Genericorum and

1566-424: A wide range of sizes, including large organisms such as jellyfish. This is because plankton are defined by their ecological niche and level of motility rather than by any phylogenetic or taxonomic classification. The "plankton" category differentiates these organisms from those that float on the water's surface, called neuston , those that can swim against a current, called nekton , and those that live on

1653-406: A wide variety of aquatic organisms that have both planktonic and benthic stages in their life cycles. Much of the meroplankton consists of larval stages of larger organisms. Meroplankton can be contrasted with holoplankton , which are planktonic organisms that stay in the pelagic zone as plankton throughout their entire life cycle. After some time in the plankton, many meroplankton graduate to

1740-409: Is also well-recognized in extensive and semi-intensive pond fish farming. Plankton population-based pond management strategies for fish rearing have been practiced by traditional fish farmers for decades, illustrating the importance of plankton even in man-made environments. Of all animal fecal matter, it is whale feces that is the 'trophy' in terms of increasing nutrient availability. Phytoplankton are

1827-538: Is because they exist in environments that are not well studied. Pandoraviruses, like other marine viruses, infect plankton , which are organisms that live in the water column and form the basis of the food chain for other marine species. More study and research needs to be done in order to confirm the prevalence of Pandoraviruses in different environments. Currently, not much is known about their role in marine ecosystems. however, viruses are not mere pathogens for their host, but are also key players in aquatic ecosystems and

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1914-476: Is dependent on light levels and nutrient availability. The chief factor limiting growth varies from region to region in the world's oceans. On a broad scale, growth of phytoplankton in the oligotrophic tropical and subtropical gyres is generally limited by nutrient supply, while light often limits phytoplankton growth in subarctic gyres. Environmental variability at multiple scales influences the nutrient and light available for phytoplankton, and as these organisms form

2001-612: Is discouraged by both the International Code of Zoological Nomenclature and the International Code of Nomenclature for algae, fungi, and plants , there are some five thousand such names in use in more than one kingdom. For instance, A list of generic homonyms (with their authorities), including both available (validly published) and selected unavailable names, has been compiled by the Interim Register of Marine and Nonmarine Genera (IRMNG). The type genus forms

2088-541: Is loss from zooplankton in the form of respired CO 2 . The relative sizes of zooplankton and prey also mediate how much carbon is released via sloppy feeding . Smaller prey are ingested whole, whereas larger prey may be fed on more "sloppily", that is more biomatter is released through inefficient consumption. There is also evidence that diet composition can impact nutrient release, with carnivorous diets releasing more dissolved organic carbon (DOC) and ammonium than omnivorous diets. The growth of phytoplankton populations

2175-501: Is made up of numerous microbes , including viruses , about 1000 different species of bacteria , around 40,000 varieties of fungi , and hundreds of species of protists , algae , mosses and liverworts that live some part of their life cycle as aeroplankton, often as spores , pollen , and wind-scattered seeds . Additionally, peripatetic microorganisms are swept into the air from terrestrial dust storms, and an even larger amount of airborne marine microorganisms are propelled high into

2262-510: Is primarily determined by the surrounding water movement, and plankton typically flow with ocean currents . This is in contrast to nekton organisms, such as fish , squid and marine mammals , which can swim against the ambient flow and control their position in the environment. Within the plankton, holoplankton spend their entire life cycle as plankton (e.g. most algae , copepods , salps , and some jellyfish ). By contrast, meroplankton are only planktic for part of their lives (usually

2349-469: Is recycled back to the marine environment. Low feeding rates typically lead to high absorption efficiency and small, dense pellets, while high feeding rates typically lead to low absorption efficiency and larger pellets with more organic content. Another contributing factor to dissolved organic matter (DOM) release is respiration rate. Physical factors such as oxygen availability, pH, and light conditions may affect overall oxygen consumption and how much carbon

2436-460: Is somewhat arbitrary. Although all species within a genus are supposed to be "similar", there are no objective criteria for grouping species into genera. There is much debate among zoologists about whether enormous, species-rich genera should be maintained, as it is extremely difficult to come up with identification keys or even character sets that distinguish all species. Hence, many taxonomists argue in favor of breaking down large genera. For instance,

2523-474: Is the type species , and the generic name is permanently associated with the type specimen of its type species. Should the specimen turn out to be assignable to another genus, the generic name linked to it becomes a junior synonym and the remaining taxa in the former genus need to be reassessed. In zoological usage, taxonomic names, including those of genera, are classified as "available" or "unavailable". Available names are those published in accordance with

2610-669: Is the availability of light. All plankton ecosystems are driven by the input of solar energy (but see chemosynthesis ), confining primary production to surface waters, and to geographical regions and seasons having abundant light. A secondary variable is nutrient availability. Although large areas of the tropical and sub-tropical oceans have abundant light, they experience relatively low primary production because they offer limited nutrients such as nitrate , phosphate and silicate . This results from large-scale ocean circulation and water column stratification . In such regions, primary production usually occurs at greater depth, although at

2697-621: The International Code of Zoological Nomenclature ; the earliest such name for any taxon (for example, a genus) should then be selected as the " valid " (i.e., current or accepted) name for the taxon in question. Consequently, there will be more available names than valid names at any point in time; which names are currently in use depending on the judgement of taxonomists in either combining taxa described under multiple names, or splitting taxa which may bring available names previously treated as synonyms back into use. "Unavailable" names in zoology comprise names that either were not published according to

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2784-824: The International Plant Names Index for plants in general, and ferns through angiosperms, respectively, and Nomenclator Zoologicus and the Index to Organism Names for zoological names. Totals for both "all names" and estimates for "accepted names" as held in the Interim Register of Marine and Nonmarine Genera (IRMNG) are broken down further in the publication by Rees et al., 2020 cited above. The accepted names estimates are as follows, broken down by kingdom: The cited ranges of uncertainty arise because IRMNG lists "uncertain" names (not researched therein) in addition to known "accepted" names;

2871-472: The Portuguese Man o' War , which are buoyant. Pseudoplankton are often found in the guts of filtering zooplankters . Tychoplankton are organisms, such as free-living or attached benthic organisms and other non-planktonic organisms, that are carried into the plankton through a disturbance of their benthic habitat, or by winds and currents. This can occur by direct turbulence or by disruption of

2958-433: The benthic zone . Examples of holoplankton include some diatoms , radiolarians , some dinoflagellates , foraminifera , amphipods , krill , copepods , and salps , as well as some gastropod mollusk species. Holoplankton dwell in the pelagic zone as opposed to the benthic zone . Holoplankton include both phytoplankton and zooplankton and vary in size. The most common plankton are protists . Meroplankton are

3045-403: The biological pump , is one reason that oceans constitute the largest carbon sink on Earth . However, it has been shown to be influenced by increments of temperature. In 2019, a study indicated that at ongoing rates of seawater acidification , Antarctic phytoplanktons could become smaller and less effective at storing carbon before the end of the century. It might be possible to increase

3132-417: The larval stage), and then graduate to either a nektic (swimming) or benthic (sea floor) existence. Examples of meroplankton include the larvae of sea urchins , starfish , crustaceans , marine worms , and most fish . The amount and distribution of plankton depends on available nutrients, the state of water and a large amount of other plankton. The study of plankton is termed planktology and

3219-426: The nekton or adopt a benthic (often sessile ) lifestyle on the seafloor . The larval stages of benthic invertebrates make up a significant proportion of planktonic communities. The planktonic larval stage is particularly crucial to many benthic invertebrates in order to disperse their young. Depending on the particular species and the environmental conditions, larval or juvenile-stage meroplankton may remain in

3306-404: The platypus belongs to the genus Ornithorhynchus although George Shaw named it Platypus in 1799 (these two names are thus synonyms ) . However, the name Platypus had already been given to a group of ambrosia beetles by Johann Friedrich Wilhelm Herbst in 1793. A name that means two different things is a homonym . Since beetles and platypuses are both members of the kingdom Animalia,

3393-473: The French botanist Joseph Pitton de Tournefort (1656–1708) is considered "the founder of the modern concept of genera". The scientific name (or the scientific epithet) of a genus is also called the generic name ; in modern style guides and science, it is always capitalised. It plays a fundamental role in binomial nomenclature , the system of naming organisms , where it is combined with the scientific name of

3480-477: The Sun and nutrients from the water to produce their own nourishment or energy. In the process of photosynthesis , phytoplankton release molecular oxygen ( O 2 ) into the water as a waste byproduct. It is estimated that about 50% of the world's oxygen is produced via phytoplankton photosynthesis. The rest is produced via photosynthesis on land by plants . Furthermore, phytoplankton photosynthesis has controlled

3567-481: The amoebal host was documented extensively. Unlike in other cases with such giant viruses, the large particles within Acanthamoeba were not mistaken for bacteria. The authors initially termed them "endocytobionts". Mimivirus , a nucleocytoplasmic large DNA virus with a genome size of about 1.1 megabases, was described in 1992 but not recognized as a virus until 2003. Megavirus , discovered in seawater off

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3654-854: The atmosphere for about 31 days. Evidence suggests that bacteria can remain viable after being transported inland through aerosols. Some reached as far as 200 meters at 30 meters above sea level. The process which transfers this material to the atmosphere causes further enrichment in both bacteria and viruses in comparison to either the SML or sub-surface waters (up to three orders of magnitude in some locations). Many animals live in terrestrial environments by thriving in transient often microscopic bodies of water and moisture, these include rotifers and gastrotrichs which lay resilient eggs capable of surviving years in dry environments, and some of which can go dormant themselves. Nematodes are usually microscopic with this lifestyle. Water bears, despite only having lifespans of

3741-466: The atmosphere in sea spray. Aeroplankton deposits hundreds of millions of airborne viruses and tens of millions of bacteria every day on every square meter around the planet. The sea surface microlayer , compared to the sub-surface waters, contains elevated concentration of bacteria and viruses . These materials can be transferred from the sea-surface to the atmosphere in the form of wind-generated aqueous aerosols due to their high vapour tension and

3828-487: The atmospheric CO 2 / O 2 balance since the early Precambrian Eon. The absorption efficiency (AE) of plankton is the proportion of food absorbed by the plankton that determines how available the consumed organic materials are in meeting the required physiological demands. Depending on the feeding rate and prey composition, variations in absorption efficiency may lead to variations in fecal pellet production, and thus regulates how much organic material

3915-442: The base for higher taxonomic ranks, such as the family name Canidae ("Canids") based on Canis . However, this does not typically ascend more than one or two levels: the order to which dogs and wolves belong is Carnivora ("Carnivores"). The numbers of either accepted, or all published genus names is not known precisely; Rees et al., 2020 estimate that approximately 310,000 accepted names (valid taxa) may exist, out of

4002-413: The base of the marine food web, this variability in phytoplankton growth influences higher trophic levels. For example, at interannual scales phytoplankton levels temporarily plummet during El Niño periods, influencing populations of zooplankton, fishes, sea birds, and marine mammals . The effects of anthropogenic warming on the global population of phytoplankton is an area of active research. Changes in

4089-750: The biosphere. Almost all genomes of cellular organisms contain viral sequences, elements of which are also essential in gene regulation. Viral infection and lysis can influence community structure, as well as the transfer of matter and energy in aquatic ecosystems. They can also dramatically alter host physiology through viral gene expression and drive evolutionary innovation through virus-mediated horizontal gene transfer. Approximately 93% of Pandoravirus genes are not known from any other microbes, suggesting that they belong to an as of yet undescribed "fourth domain" aside from Bacteria , Archaea , and Eukaryotes . Viruses are not widely considered to belong within these three domains, although they have been proposed as one in

4176-457: The characteristics of bacteria, such as the ability to make their own proteins. The dissimilarity of the remaining genes to any cellular genes led researchers to speculate that this virus represents a previously unknown branch of the tree of life . However, other experts have called this proposal premature because there is very little evidence supporting the idea. Pandoraviruses have double stranded DNA. Like most giant viruses, Pandoraviruses have

4263-530: The coast of Chile in 2011, has a genome size of approximately 1.2 megabases. The prior discovery of these viruses prompted a search for other types of large amoeba-infecting viruses, which led to the finding of two species; Pandoravirus salinus , found in seawater taken from the coast of Chile, with a genome size of ~2.5 megabases, and Pandoravirus dulcis , found in a shallow freshwater pond in La Trobe University , Melbourne, Australia , with

4350-433: The deep sea floor, called benthos . The name plankton was coined by German marine biologist Victor Hensen in 1887 from shortening the word halyplankton from Greek ᾰ̔́λς háls "sea" and πλανάω planáō to "drift" or "wander". While some forms are capable of independent movement and can swim hundreds of meters vertically in a single day (a behavior called diel vertical migration ), their horizontal position

4437-581: The density and distribution of zooplankton to match that of new larvae, which can otherwise starve. Natural factors (e.g., current variations, temperature changes) and man-made factors (e.g. river dams, ocean acidification , rising temperatures) can strongly affect zooplankton populations, which can in turn strongly affect fish larval survival, and therefore breeding success. It has been shown that plankton can be patchy in marine environments where there aren't significant fish populations and additionally, where fish are abundant, zooplankton dynamics are influenced by

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4524-516: The eastern Atlantic Ocean , where trade winds bring dust from the Sahara Desert in north Africa ). While plankton are most abundant in surface waters, they live throughout the water column. At depths where no primary production occurs, zooplankton and bacterioplankton instead consume organic material sinking from more productive surface waters above. This flux of sinking material, so-called marine snow , can be especially high following

4611-438: The fish predation rate in their environment. Depending on the predation rate, they could express regular or chaotic behavior. A negative effect that fish larvae can have on planktonic algal blooms is that the larvae will prolong the blooming event by diminishing available zooplankton numbers; this in turn permits excessive phytoplankton growth allowing the bloom to flourish . The importance of both phytoplankton and zooplankton

4698-446: The form "author, year" in zoology, and "standard abbreviated author name" in botany. Thus in the examples above, the genus Canis would be cited in full as " Canis Linnaeus, 1758" (zoological usage), while Hibiscus , also first established by Linnaeus but in 1753, is simply " Hibiscus L." (botanical usage). Each genus should have a designated type , although in practice there is a backlog of older names without one. In zoology, this

4785-475: The freshwaters of lakes and rivers. Aeroplankton are tiny lifeforms that float and drift in the air, carried by the current of the wind ; they are the atmospheric analogue to oceanic plankton. Most of the living things that make up aeroplankton are very small to microscopic in size, and many can be difficult to identify because of their tiny size. Scientists can collect them for study in traps and sweep nets from aircraft , kites or balloons. Aeroplankton

4872-737: The generic name (or its abbreviated form) still forms the leading portion of the scientific name, for example, Canis lupus lupus for the Eurasian wolf subspecies, or as a botanical example, Hibiscus arnottianus ssp. immaculatus . Also, as visible in the above examples, the Latinised portions of the scientific names of genera and their included species (and infraspecies, where applicable) are, by convention, written in italics . The scientific names of virus species are descriptive, not binomial in form, and may or may not incorporate an indication of their containing genus; for example,

4959-503: The influence of currents. Although plankton are usually thought of as inhabiting water, there are also airborne versions that live part of their lives drifting in the atmosphere. These aeroplankton include plant spores , pollen and wind-scattered seeds . They may also include microorganisms swept into the air from terrestrial dust storms and oceanic plankton swept into the air by sea spray . Though many planktonic species are microscopic in size, plankton includes organisms over

5046-633: The largest component, with 23,236 ± 5,379 accepted genus names, of which 20,845 ± 4,494 are angiosperms (superclass Angiospermae). By comparison, the 2018 annual edition of the Catalogue of Life (estimated >90% complete, for extant species in the main) contains currently 175,363 "accepted" genus names for 1,744,204 living and 59,284 extinct species, also including genus names only (no species) for some groups. The number of species in genera varies considerably among taxonomic groups. For instance, among (non-avian) reptiles , which have about 1180 genera,

5133-499: The largest proportion of all plankton in number and diversity. The microplankton and smaller groups are microorganisms and operate at low Reynolds numbers , where the viscosity of water is more important than its mass or inertia. Marine plankton includes marine bacteria and archaea , algae , protozoa and drifting or floating animals that inhabit the saltwater of oceans and the brackish waters of estuaries. Freshwater plankton are similar to marine plankton, but are found inland in

5220-474: The lizard genus Anolis has been suggested to be broken down into 8 or so different genera which would bring its ~400 species to smaller, more manageable subsets. Plankton This is an accepted version of this page Plankton are the diverse collection of organisms that drift in water (or air ) but are unable to actively propel themselves against currents (or wind ). The individual organisms constituting plankton are called plankters . In

5307-408: The membrane vacuole of the amoeba. This leads to viral particles to be released into the cytoplasm of the amoeba. Genus The composition of a genus is determined by taxonomists . The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that

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5394-403: The most (>300) have only 1 species, ~360 have between 2 and 4 species, 260 have 5–10 species, ~200 have 11–50 species, and only 27 genera have more than 50 species. However, some insect genera such as the bee genera Lasioglossum and Andrena have over 1000 species each. The largest flowering plant genus, Astragalus , contains over 3,000 species. Which species are assigned to a genus

5481-428: The name could not be used for both. Johann Friedrich Blumenbach published the replacement name Ornithorhynchus in 1800. However, a genus in one kingdom is allowed to bear a scientific name that is in use as a generic name (or the name of a taxon in another rank) in a kingdom that is governed by a different nomenclature code. Names with the same form but applying to different taxa are called "homonyms". Although this

5568-449: The ocean currents. Fish eggs cannot swim at all, and are unambiguously planktonic. Early stage larvae swim poorly, but later stage larvae swim better and cease to be planktonic as they grow into juveniles . Fish larvae are part of the zooplankton that eat smaller plankton, while fish eggs carry their food supply. Both eggs and larvae are themselves eaten by larger animals. Fish can produce high numbers of eggs which are often released into

5655-465: The ocean's carbon cycle . Fish larvae mainly eat zooplankton, which in turn eat phytoplankton Primarily by grazing on phytoplankton, zooplankton provide carbon to the planktic foodweb , either respiring it to provide metabolic energy, or upon death as biomass or detritus . Organic material tends to be denser than seawater , so it sinks into open ocean ecosystems away from the coastlines, transporting carbon along with it. This process, called

5742-451: The ocean's uptake of carbon dioxide ( CO 2 ) generated through human activities by increasing plankton production through iron fertilization – introducing amounts of iron into the ocean. However, this technique may not be practical at a large scale. Ocean oxygen depletion and resultant methane production (caused by the excess production remineralising at depth) is one potential drawback. Phytoplankton absorb energy from

5829-578: The ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves , fish , and baleen whales . Marine plankton include bacteria , archaea , algae , protozoa , microscopic fungi , and drifting or floating animals that inhabit the saltwater of oceans and the brackish waters of estuaries . Freshwater plankton are similar to marine plankton, but are found in lakes and rivers. Mostly, plankton just drift where currents take them, though some, like jellyfish , swim slowly but not fast enough to generally overcome

5916-408: The open ocean and the deep sea and are less available to the casual ocean observer. Ichthyoplankton are the eggs and larvae of fish. They are mostly found in the sunlit zone of the water column , less than 200 metres deep, which is sometimes called the epipelagic or photic zone . Ichthyoplankton are planktonic , meaning they cannot swim effectively under their own power, but must drift with

6003-606: The open water column. Fish eggs typically have a diameter of about 1 millimetre (0.039 in). The newly hatched young of oviparous fish are called larvae . They are usually poorly formed, carry a large yolk sac (for nourishment), and are very different in appearance from juvenile and adult specimens. The larval period in oviparous fish is relatively short (usually only several weeks), and larvae rapidly grow and change appearance and structure (a process termed metamorphosis ) to become juveniles. During this transition larvae must switch from their yolk sac to feeding on zooplankton prey,

6090-416: The oxygen in the atmosphere is produced in the oceans from phytoplankton performing photosynthesis, meaning that the majority of the oxygen available for us and other organisms that respire aerobically is produced by plankton. Plankton also make up the base of the marine food web, providing food for all the trophic levels above. Recent studies have analyzed the marine food web to see if the system runs on

6177-681: The past by some biologists. Other giant viruses such as the Mimivirus , Pithovirus , and Megavirus have much smaller genomes. For example, Mimivirus , considered one of the largest giant viruses, has a genome size of 1.1 million base pairs compared to 2.5 million base pairs for Pandoraviruses. Another feature that is different in Pandoraviruses compared to other giant viruses is the replication cycle. Pandoraviruses infect amoebas , which are single celled eukaryotes. Pandoravirus enters amoebas through phagocytic vacuoles , then fuses with

6264-453: The pelagic zone for durations ranging from hours to months. Pseudoplankton are organisms that attach themselves to planktonic organisms or other floating objects, such as drifting wood, buoyant shells of organisms such as Spirula , or man-made flotsam . Examples include goose barnacles and the bryozoan Jellyella . By themselves these animals cannot float , which contrasts them with true planktonic organisms, such as Velella and

6351-433: The powerhouse of open ocean primary production and they can acquire many nutrients from whale feces. In the marine food web, phytoplankton are at the base of the food web and are consumed by zooplankton & krill, which are preyed upon by larger and larger marine organisms, including whales, so it can be said that whale poop fuels the entire food web. Plankton have many direct and indirect effects on humans. Around 70% of

6438-541: The provisions of the ICZN Code, e.g., incorrect original or subsequent spellings, names published only in a thesis, and generic names published after 1930 with no type species indicated. According to "Glossary" section of the zoological Code, suppressed names (per published "Opinions" of the International Commission of Zoological Nomenclature) remain available but cannot be used as the valid name for

6525-414: The secondary consumers that prey on the primary consumers. In some cases, plankton act as an intermediate host for deadly parasites in humans. One such case is that of cholera , an infection caused by several pathogenic strains of Vibrio cholerae . These species have been shown to have a symbiotic relationship with chitinous zooplankton species like copepods . These bacteria benefit not only from

6612-497: The specific name particular to the wolf. A botanical example would be Hibiscus arnottianus , a particular species of the genus Hibiscus native to Hawaii. The specific name is written in lower-case and may be followed by subspecies names in zoology or a variety of infraspecific names in botany . When the generic name is already known from context, it may be shortened to its initial letter, for example, C. lupus in place of Canis lupus . Where species are further subdivided,

6699-412: The standard format for a species name comprises the generic name, indicating the genus to which the species belongs, followed by the specific epithet, which (within that genus) is unique to the species. For example, the gray wolf 's scientific name is Canis lupus , with Canis ( Latin for 'dog') being the generic name shared by the wolf's close relatives and lupus (Latin for 'wolf') being

6786-538: The substrate and subsequent entrainment in the water column. Tychoplankton are, therefore, a primary subdivision for sorting planktonic organisms by duration of lifecycle spent in the plankton, as neither their entire lives nor particular reproductive portions are confined to planktonic existence. Tychoplankton are sometimes called accidental plankton . Apart from aeroplankton, plankton inhabits oceans, seas, lakes and ponds. Local abundance varies horizontally, vertically and seasonally. The primary cause of this variability

6873-403: The taxon is termed a synonym ; some authors also include unavailable names in lists of synonyms as well as available names, such as misspellings, names previously published without fulfilling all of the requirements of the relevant nomenclatural code, and rejected or suppressed names. A particular genus name may have zero to many synonyms, the latter case generally if the genus has been known for

6960-406: The termination of spring blooms . The local distribution of plankton can be affected by wind-driven Langmuir circulation and the biological effects of this physical process. As well as representing the lower levels of a food chain that supports commercially important fisheries , plankton ecosystems play a role in the biogeochemical cycles of many important chemical elements , including

7047-576: The values quoted are the mean of "accepted" names alone (all "uncertain" names treated as unaccepted) and "accepted + uncertain" names (all "uncertain" names treated as accepted), with the associated range of uncertainty indicating these two extremes. Within Animalia, the largest phylum is Arthropoda , with 151,697 ± 33,160 accepted genus names, of which 114,387 ± 27,654 are insects (class Insecta). Within Plantae, Tracheophyta (vascular plants) make up

7134-477: The vertical stratification of the water column, the rate of temperature-dependent biological reactions, and the atmospheric supply of nutrients are expected to have important impacts on future phytoplankton productivity. Additionally, changes in the mortality of phytoplankton due to rates of zooplankton grazing may be significant. Zooplankton are the initial prey item for almost all fish larvae as they switch from their yolk sacs to external feeding. Fish rely on

7221-449: The viral particles. The process of replication lasts 10–15 hours. Viral replication and assembly happens simultaneously. In other words, viral DNA is replicated within the cytoplasm of the host cell and assembled into new viral particles followed by lysis of the host cell. Pandoraviruses do not seem to be harmful to humans. They are mostly found in marine environments, infecting amoebae. One reason for their only relatively recent discovery

7308-429: The virus species " Salmonid herpesvirus 1 ", " Salmonid herpesvirus 2 " and " Salmonid herpesvirus 3 " are all within the genus Salmonivirus ; however, the genus to which the species with the formal names " Everglades virus " and " Ross River virus " are assigned is Alphavirus . As with scientific names at other ranks, in all groups other than viruses, names of genera may be cited with their authorities, typically in

7395-522: The water column in the ocean. Their delicate bodies have no hard parts and are easily damaged or destroyed. Gelatinous zooplankton are often transparent. All jellyfish are gelatinous zooplankton, but not all gelatinous zooplankton are jellyfish. The most commonly encountered organisms include ctenophores , medusae , salps , and Chaetognatha in coastal waters. However, almost all marine phyla, including Annelida , Mollusca and Arthropoda , contain gelatinous species, but many of those odd species live in

7482-521: The word is neuter) is normally dropped, using only the root of the word in the derivation. Plankton are primarily divided into broad functional (or trophic level ) groups: Recognition of the importance of mixotrophy as an ecological strategy is increasing, as well as the wider role this may play in marine biogeochemistry . Studies have shown that mixotrophs are much more important for marine ecology than previously assumed and comprise more than half of all microscopic plankton. Their presence acts as

7569-692: Was announced in a report in the journal Science in July 2013. Other scientists had previously observed the pandoravirus particles, but owing to their enormous size they were not expected to be viruses. Patrick Scheid, a parasitologist from the Central Institute of the Bundeswehr Medical Service in Koblenz , Germany, found one in 2008, in an amoeba living in the contact lens of a woman with keratitis . Its development within

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