63-454: 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
126-551: A certain degree of morphological or developmental similarity (the phenetic definition), or a group of organisms with a certain degree of evolutionary relatedness (the phylogenetic definition). Attempting to define a level of the Linnean hierarchy without referring to (evolutionary) relatedness is unsatisfactory, but a phenetic definition is useful when addressing questions of a morphological nature—such as how successful different body plans were. The most important objective measure in
189-407: A character unique to a sub-set of the crown group. Furthermore, organisms in the stem group of a phylum can possess the "body plan" of the phylum without all the characteristics necessary to fall within it. This weakens the idea that each of the phyla represents a distinct body plan. A classification using this definition may be strongly affected by the chance survival of rare groups, which can make
252-552: A family Telonemidae , order Telonemida and class Telonemea to contain this protist . Initially, this group was included within the now obsolete phylum Opalozoa , along with other unrelated groups of flagellates such as apusomonads , jakobids , cercomonads , spongomonads , katablepharids , ebriids , proteomyxids and so on. In this scheme, the class Telonemea was distinguished by the presence of two posterior cilia of equal length (isokont cilia). It contained an additional order besides Telonemida, Nephromycida, which comprised
315-434: A formation superficially resembling the apical complex of apicomplexans . All telonemid genera possess a highly intricate multi-layered cytoskeleton , whose complexity is not found in any other eukaryote. This finding may indicate that telonemids have retained an ancestral cytoskeleton organization that has been lost in other eukaryotes. Phylum In biology , a phylum ( / ˈ f aɪ l əm / ; pl. : phyla )
378-402: A group ("a self-contained unity"): "perhaps such a real and completely self-contained unity is the aggregate of all species which have gradually evolved from one and the same common original form, as, for example, all vertebrates. We name this aggregate [a] Stamm [i.e., stock] ( Phylon )." In plant taxonomy , August W. Eichler (1883) classified plants into five groups named divisions,
441-596: A group containing Viridiplantae and the algal Rhodophyta and Glaucophyta divisions. The definition and classification of plants at the division level also varies from source to source, and has changed progressively in recent years. Thus some sources place horsetails in division Arthrophyta and ferns in division Monilophyta, while others place them both in Monilophyta, as shown below. The division Pinophyta may be used for all gymnosperms (i.e. including cycads, ginkgos and gnetophytes), or for conifers alone as below. Since
504-400: A phylum based on body plan has been proposed by paleontologists Graham Budd and Sören Jensen (as Haeckel had done a century earlier). The definition was posited because extinct organisms are hardest to classify: they can be offshoots that diverged from a phylum's line before the characters that define the modern phylum were all acquired. By Budd and Jensen's definition, a phylum is defined by
567-471: A phylum much more diverse than it would be otherwise. Total numbers are estimates; figures from different authors vary wildly, not least because some are based on described species, some on extrapolations to numbers of undescribed species. For instance, around 25,000–27,000 species of nematodes have been described, while published estimates of the total number of nematode species include 10,000–20,000; 500,000; 10 million; and 100 million. The kingdom Plantae
630-689: A phylum, other phylum-level ranks appear, such as the case of Bacillariophyta (diatoms) within Ochrophyta . These differences became irrelevant after the adoption of a cladistic approach by the ISP, where taxonomic ranks are excluded from the classifications after being considered superfluous and unstable. Many authors prefer this usage, which lead to the Chromista-Protozoa scheme becoming obsolete. Currently there are 40 bacterial phyla (not including " Cyanobacteria ") that have been validly published according to
693-614: A possible transitional form between ecologically important heterotrophic and photosynthetic species among chromalveolates. The present phylogenetic analyses place them as sister to the SAR supergroup in a clade commonly known as TSAR , which is widely accepted by the scientific community. As the sister clade to SAR, Telonemia has a key position in the tree of eukaryotic life. They are morphologically complex organisms that combine characteristics of different SAR lineages. The main trait uniting each SAR lineage has been described in at least one genus of Telonemia: tripartite mastigonemes in
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#1732876310293756-401: A set of characters shared by all its living representatives. This approach brings some small problems—for instance, ancestral characters common to most members of a phylum may have been lost by some members. Also, this definition is based on an arbitrary point of time: the present. However, as it is character based, it is easy to apply to the fossil record. A greater problem is that it relies on
819-654: A short proboscis -like structure, known as a rostrum. Their mitochondrial cristae are tubular. They have a unique multi-layered cytoskeleton of high complexity, composed of layers of microfilaments and microtubules , unseen in any other eukaryote. They exhibit a unique combination of cell traits that were previously believed to be exclusive to different chromalveolate groups, such as complex tripartite mastigonemes (as in stramenopiles ), cortical alveoli -like structures (as in alveolates ) and filopodia (as in rhizarians ). Despite their evolutionary proximity to chromalveolates, they lack chloroplasts . Telonemids feed on
882-401: A subjective decision about which groups of organisms should be considered as phyla. The approach is useful because it makes it easy to classify extinct organisms as " stem groups " to the phyla with which they bear the most resemblance, based only on the taxonomically important similarities. However, proving that a fossil belongs to the crown group of a phylum is difficult, as it must display
945-424: A term that remains in use today for groups of plants, algae and fungi. The definitions of zoological phyla have changed from their origins in the six Linnaean classes and the four embranchements of Georges Cuvier . Informally, phyla can be thought of as groupings of organisms based on general specialization of body plan . At its most basic, a phylum can be defined in two ways: as a group of organisms with
1008-586: A third genus, Arpakorses , were described by protistologist Denis Victorovich Tikhonenkov and coauthors. Until 2019, only two species had been formally described , although DNA sequences collected from seawater suggested there were many more species not yet described. In 2022, five additional species were described along with a third new genus, bringing the total number of species to seven. Stramenopila Alveolata Rhizaria Telonemia Haptista Cryptista Archaeplastida Amoebozoa Obazoa CRuMs Excavates Hemimastigophora Telonemia
1071-707: A wide range of organisms, namely bacteria and phytoplankton ranging in size between pico- and nanoplankton . They are widely distributed and are sometimes abundant, implying they may play an important ecological role in aquatic ecosystems . Around one hundred clades of environmental sequences from undescribed telonemids have been recovered in a variety of marine locations ( Antarctic , Arctic and Indian Oceans ; Mediterranean , Baltic , Kara , Marmara and White seas), including deep sea , and freshwater bodies from different regions ( Norway , France , Antarctica , Finland , Canada , Japan ). Several telonemid clades favor open waters with lower nutrients, such as
1134-561: Is a clade of protists that branch independently from other eukaryotic supergroups groups as their own 'micro-kingdom'. Early molecular analyses of Telonemia placed them as an independent branch within the SAR supergroup , a diverse clade of eukaryotes that contain Rhizaria , Alveolata and Stramenopila . Other analyses proposed a close relationship with centrohelids , katablepharids , cryptomonads and haptophytes . At this time, they were suggested to have evolutionary significance in being
1197-467: Is a paraphyletic taxon, which is less acceptable to present-day biologists than in the past. Proposals have been made to divide it among several new kingdoms, such as Protozoa and Chromista in the Cavalier-Smith system . Protist taxonomy has long been unstable, with different approaches and definitions resulting in many competing classification schemes. Many of the phyla listed below are used by
1260-640: Is a developing seaweed industry. The White Sea is an important traffic centre of northwestern Russia, interconnecting various economic regions and providing an outlet to the foreign routes. The White Sea–Baltic Canal links it through Lake Onega to the Baltic Sea and the major city and port of Saint Petersburg . The Baltic Sea, in turn, is connected by the Volga–Baltic Waterway to the Volga River , Black , Caspian , and Azov seas. The major ports on
1323-476: Is a level of classification or taxonomic rank below kingdom and above class . Traditionally, in botany the term division has been used instead of phylum, although the International Code of Nomenclature for algae, fungi, and plants accepts the terms as equivalent. Depending on definitions, the animal kingdom Animalia contains about 31 phyla, the plant kingdom Plantae contains about 14 phyla, and
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#17328763102931386-683: Is a southern inlet of the Barents Sea located on the northwest coast of Russia . It is surrounded by Karelia to the west, the Kola Peninsula to the north, and the Kanin Peninsula to the northeast. The whole of the White Sea is under Russian sovereignty and considered to be part of the internal waters of Russia. Administratively, it is divided between the Arkhangelsk and Murmansk oblasts and
1449-561: Is an underwater ridge in the northern part of the gorlo , resulting in maximum depths of 40 metres in that part. This hinders water exchange between the White and Barents seas. The exchange is assisted by the tides , which are semidiurnal (rising twice a day), with the amplitude increasing from 1 metre on the south to 10 metres in Mezen Bay. Currents are rather weak in the open seas with the speed below 1 km/h, but they significantly strengthen in
1512-580: Is brought during the snow melting in May, and the inflow is minimal in February–March. This inflow raises and lowers the sea level that promotes the water exchange with the Barents Sea. As a result, annually, about 2,000 km and 2,200 km flow in and out of the White Sea, respectively. The inflow of fresh water in spring decreases the surface salinity in the top 5–10-metre layer to 23‰ (parts per thousand) in
1575-405: Is defined in various ways by different biologists (see Current definitions of Plantae ). All definitions include the living embryophytes (land plants), to which may be added the two green algae divisions, Chlorophyta and Charophyta , to form the clade Viridiplantae . The table below follows the influential (though contentious) Cavalier-Smith system in equating "Plantae" with Archaeplastida ,
1638-472: Is generally included in kingdom Fungi, though its exact relations remain uncertain, and it is considered a protozoan by the International Society of Protistologists (see Protista , below). Molecular analysis of Zygomycota has found it to be polyphyletic (its members do not share an immediate ancestor), which is considered undesirable by many biologists. Accordingly, there is a proposal to abolish
1701-511: Is one of the four seas named (not only in English) after common colour terms —the others being the Black , Red and Yellow seas. The International Hydrographic Organization defines the northern limit of the White Sea as "A line joining Svyatoy Nos ( Murmansk Coast, 39°47'E) and Cape Kanin ". There are four main bays or gulfs on the White Sea. These bays connect with the funnel-shaped opening to
1764-586: The Bacteriological Code Currently there are 2 phyla that have been validly published according to the Bacteriological Code Other phyla that have been proposed, but not validly named, include: White Sea The White Sea ( Russian : Белое море , romanized : Beloye more ; Karelian and Finnish : Vienanmeri , lit. 'Dvina Sea'; Nenets : Сэрако ямʼ , romanized: Serako yam )
1827-561: The Canada Basin and offshore the Mackenzie River , suggesting that they are able to thrive in low-productivity ecosystems (i.e. oligotrophic ). The first telonemid genus and species , Telonema subtile , was described by Karl Griessmann in 1913 from crude cultures of the green alga Ulva and of red algae off the coast of Roscoff and Naples . Eighty years later, in 1993, American protistologist Thomas Cavalier-Smith created
1890-552: The Catalogue of Life , and correspond to the Protozoa-Chromista scheme, with updates from the latest (2022) publication by Cavalier-Smith . Other phyla are used commonly by other authors, and are adapted from the system used by the International Society of Protistologists (ISP). Some of the descriptions are based on the 2019 revision of eukaryotes by the ISP. The number of protist phyla varies greatly from one classification to
1953-514: The Republic of Karelia . The major port of Arkhangelsk is located on the White Sea. For much of Russia's history this was Russia's main centre of international maritime trade, conducted by the Pomors ("seaside settlers") from Kholmogory . In the modern era it became an important Soviet naval and submarine base. The White Sea–Baltic Canal connects the White Sea with the Baltic Sea . The White Sea
Telonemia - Misplaced Pages Continue
2016-421: The diversity of telonemids is morphologically uncharacterized. The few described species are free-living predatory phagotrophic flagellates composed of pear-shaped cells with two flagella . These cells measure approximately 5–10 μm in length and 3–7 μm in width. The flagella have different lengths, with the short one measuring up to 12 μm and the long one measuring up to 16 μm. Between the flagella protrudes
2079-615: The flagella , typical of stramenopiles and described in Lateronema ; cortical alveoli underneath the plasma membrane , typical of alveolates and described in Lateronema ; and fine pseudopodia ( filopodia ), typical of rhizarians and described in Telonema . Moreover, Arpakorses presents a kinetid structure similar to that seen in Rhizaria, and Telonema subtile presents microtubules in
2142-644: The 'gorlo', opposite to the Kola Peninsula , is Mezen Bay . It receives the Mezen River and the Kuloy River . Other major rivers flowing into the sea are the Vyg , Niva , Umba , Varzuga and Ponoy . The seabed of the central part and Dvina Bay is covered in silt and sand, whereas the bottom of the northern part, the Kandalaksha Gulf and Onega Bay is a mixture of sand and stones. Ice age deposits often emerge near
2205-666: The Baltic Sea. From the 1920s, most northern Russian sea shipments diverted from the White Sea to the new port of Murmansk (officially founded in 1916), where the waters did not freeze in winter. The entire water area of the White Sea is the territorial waters of the Russian Federation. Any movement of foreign vessels on the White Sea is carried out in accordance with the legislation of the Russian Federation. The sea hosts more than 700 species of invertebrates , about 60 species of fish, and five species of marine mammals, including
2268-559: The Barents Sea via a narrow strait called " Gorlo " ( Russian : Горло , meaning "throat"). Kandalaksha Gulf lies in the western part of the White Sea; it is the deepest part of the sea, reaching 340 metres (1,115 feet). On the south, Onega Bay receives the Onega River . To the southeast, the Dvina Bay receives the Northern Dvina at the major port of Arkhangelsk . On the east side of
2331-566: The White Sea route. Dutch ships soon followed the English, and the port of Kholmogory became busy with shipments of fur and fish. Local and foreign shops and factories were established in the city at that time. The port was reinforced with a fortress which sustained a siege by the Polish-Lithuanian army in 1613. Increasing traffic overloaded the port, which relied on shallow river-waters and had limited ship-capacity. However, instead of expanding
2394-491: The Zygomycota phylum. Its members would be divided between phylum Glomeromycota and four new subphyla incertae sedis (of uncertain placement): Entomophthoromycotina , Kickxellomycotina , Mucoromycotina , and Zoopagomycotina . Kingdom Protista (or Protoctista) is included in the traditional five- or six-kingdom model, where it can be defined as containing all eukaryotes that are not plants, animals, or fungi. Protista
2457-458: The above definitions is the "certain degree" that defines how different organisms need to be members of different phyla. The minimal requirement is that all organisms in a phylum should be clearly more closely related to one another than to any other group. Even this is problematic because the requirement depends on knowledge of organisms' relationships: as more data become available, particularly from molecular studies, we are better able to determine
2520-466: The basis of phylogenetic distance from Telonema . Numerous phylogenetic analyses in the following years solidified the position of Telonemia as the sister clade to the SAR supergroup , both collectively composing the TSAR clade ( T elonemia, S tramenopila, A lveolata and R hizaria), which lead Cavalier-Smith to finally consider Telonemia a separate phylum in 2022. In the same year, five more species and
2583-714: The bays. The tidal waves are much faster than the regular currents and reach the speeds of 9 km/h in Mezen Bay, 3.6 km/h in Onega Bay and 1.3 km/h in the Kandalaksha Gulf. Rivers bring annually about 215 km of fresh water, on average, mostly to the Onega, Mezen and Dvina bays. The Northern Dvina alone may contribute up to 171 km in some years, with the Mezen, Onega, Kem and Vyg rivers adding up to 38.5, 27.0, 12.5 and 11.5 km , respectively. About 40% of this volume
Telonemia - Misplaced Pages Continue
2646-718: The cell body. These projections can serve various purposes, such as aiding in movement or capturing food particles by wrapping around them. Together, the two lineages compose the TSAR clade. This phylum is monotypic , composed of a single class Telonemea , order Telonemida and family Telonemidae . It is classified in three genera and seven species , although numerous undescribed clades of environmental DNA are known. They are detected in all marine and freshwater environments, where they prey on bacteria and small phytoplankton by engulfing them in their plasma membrane ( phagotrophy ). The phylum Telonemia comprises microscopic unicellular eukaryotes , or protists . Most of
2709-450: 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
2772-404: The central part, but remains relatively cold in the north, at 7–8 °С, due to the water exchange between the surface and the cold bottom part which is enhanced by the shallow depths in the northern parts. Deep sea (about 100 m or more) is characterised by stable temperature (−1.4 °С) and salinity (30‰). The depth distribution of water temperature is very inhomogeneous across the sea. For example, at
2835-497: The command of Hugh Willoughby , his crew had sought a northern route to the Indies , especially India and China. The expedition, sponsored by King Edward VI of England and a group of about 240 English merchants, had London's authorisation to establish trade connections. The ships of Willoughby were separated and the other two were lost at sea, but Edward Bonaventure managed to pass the White Sea and reach Kholmogory, from where Chancellor
2898-739: The eastern and 26–27‰ in the western parts of the sea, reaching 10–12‰ in Dvina Bay; it also increases the content of silicon and silicates in water, which is a characteristic feature of the White Sea. Storms are the strongest in October–November. Shallow sea depths reduce the wave height to the average of 1 metre, sometimes reaching 3–5 metres. The sea is quiet in July–August. The climate varies between polar and subarctic with frequent fogs and clouds. Winds are predominantly southwestern in winter with speeds of 4–8 m/s. They bring cold air from
2961-402: The exit from Dvina Bay, water temperature drops to 0 °C at the depth of only 12–15 m, but the same temperature is reached at 65 m at the exit from the Kandalaksha Gulf. Residents of Novgorod knew of the White Sea from at least the 11th century and rapidly explored its commercial significance for navigation and its coastal forests rich in fur animals . One of the earliest settlements near
3024-504: The first publication of the APG system in 1998, which proposed a classification of angiosperms up to the level of orders , many sources have preferred to treat ranks higher than orders as informal clades. Where formal ranks have been provided, the traditional divisions listed below have been reduced to a very much lower level, e.g. subclasses . Wolf plants Hepatophyta Liver plants Coniferophyta Cone-bearing plant Phylum Microsporidia
3087-533: The friendly beluga and the white whale. Several other dolphin species, such as harbour porpoises , appear less frequently while larger whales such as bowhead , humpback and rorquals , northern bottlenose , orcas have been considered as rare visitors to the waters while actual frequency of occurrences within White Sea basin is not specified. The fishing industry is relatively small, mostly targeting harp seal , ringed seal , herring , saffron cod , European smelt , Atlantic cod and Atlantic salmon . There
3150-579: The fungus kingdom Fungi contains about 8 phyla. Current research in phylogenetics is uncovering the relationships among phyla within larger clades like Ecdysozoa and Embryophyta . The term phylum was coined in 1866 by Ernst Haeckel from the Greek phylon ( φῦλον , "race, stock"), related to phyle ( φυλή , "tribe, clan"). Haeckel noted that species constantly evolved into new species that seemed to retain few consistent features among themselves and therefore few features that distinguished them as
3213-614: The genus Nephromyces (later treated as an apicomplexan ). In 2005 a second species of telonemid was described, T. antarcticum , from the surface waters of the Oslofjord . Since 2006, Telonemea was separated into a new eukaryotic phylum Telonemia by protistologist Kamran Shalchian-Tabrizi and coauthors, on the basis of phylogenetic analyses that placed it near chromalveolate groups such as Haptista and Cryptista . However, in 2015, Cavalier-Smith and coauthors rejected their treatment as an independent phylum and transferred Telonemea to
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#17328763102933276-411: The next. The Catalogue of Life includes Rhodophyta and Glaucophyta in kingdom Plantae, but other systems consider these phyla part of Protista. In addition, less popular classification schemes unite Ochrophyta and Pseudofungi under one phylum, Gyrista , and all alveolates except ciliates in one phylum Myzozoa , later lowered in rank and included in a paraphyletic phylum Miozoa . Even within
3339-429: The old port, Ivan IV established a new one down-river in 1584, called New Kholmogory, which from 1596 began to become known as Arkhangelsk. Between the 15th and early 18th centuries, the White Sea served as the major trade route in and out of Russia. This role decreased later after the foundation of Saint Petersburg (1703), which opened a more direct ice-free connection between Russia and the bulk of Western Europe via
3402-528: The other hand, the highly parasitic phylum Mesozoa was divided into two phyla ( Orthonectida and Rhombozoa ) when it was discovered the Orthonectida are probably deuterostomes and the Rhombozoa protostomes . This changeability of phyla has led some biologists to call for the concept of a phylum to be abandoned in favour of placing taxa in clades without any formal ranking of group size. A definition of
3465-407: The phylum Cryptista , under the obsolete subphylum Corbihelia . This subphylum included other protists with a pharyngeal basket or radiating axopodia such as Picomonas (later classified as a separate phylum Picozoa closely related to red algae ) and Microheliella (now proposed as the sister group to Cryptista). In addition, they transferred T. antarcticum to a new genus Lateronema , on
3528-469: The relationships between groups. So phyla can be merged or split if it becomes apparent that they are related to one another or not. For example, the bearded worms were described as a new phylum (the Pogonophora) in the middle of the 20th century, but molecular work almost half a century later found them to be a group of annelids , so the phyla were merged (the bearded worms are now an annelid family ). On
3591-625: The sea shores grew up in the late 14th century at Kholmogory , on the Northern Dvina . From there, in 1492, a merchant fleet laden with grain and carrying ambassadors of Ivan III of Russia sailed to Denmark, marking the establishment of the first international seaport in Russia . The first foreign ship to arrive in Kholmogory was the English Edward Bonaventure commanded by Richard Chancellor in 1553. Together with two other ships under
3654-477: The sea shores. Northwestern coasts are tall and rocky but the slope is much weaker at the southeastern side. The White Sea contains a large number of islands, but most of them are small. The main island group is the Solovetsky Islands , located almost in the middle of the sea, near the entrance to Onega Bay. Kiy Island in Onega Bay is significant due to a historic monastery. Velikiy Island, located close to
3717-449: The sea, which increases from 24 to 26‰ in the centre to 30.5‰ in the gorlo , reaching 34.0–34.5‰ toward the Barents Sea. The freezing period varies from year to year as shown in the satellite image to the right. The ice is not stationary, but 90% of it is floating and is continuously removed to the Barents Sea. Ice thickness is usually about 40 cm but may reach 150 cm in cold winters. In summer, surface water warms up to 15 °С in
3780-626: The shore, is the largest island in the Kandalaksha Gulf. The White Sea is a water-filled depression in the block of a continental shelf known as the Baltic Shield . Its bottom is very uneven and contains the Kandalaksha Hollow in the northwest and the Solovetsky Islands in the south. Also, the Onega Bay has many small underwater elevations. The opening and the gorlo of the sea are rather shallow, with depths about 50 metres or less. There
3843-609: The south, establishing the temperature of about −15 °C (February) over most of the sea. The northern part is warmer at about −9 °C, sometimes reaching −6 °C, due to the warm air masses from the Atlantic. Arctic anticyclones, however, change winds to the northeastern ones, bringing much colder weather with temperatures of about −25 °C. Summers are cold, cloudy and relatively humid, with northeastern winds and frequent rains. Average July temperatures are 8–10 °C. Occasional southeastern winds bring warm air from Europe, raising
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#17328763102933906-439: The temperature to 17–19 °C and sometimes even to 30 °C. Annual precipitations increase from 282 mm in the north 529 in the south. In winter, from October–November to April–May, the sea freezes, with the average January water temperatures of −1.9 °C in the north, between −1.3 and −1.7 °С in the centre, and between −0.5 and −0.7 °С in the bays. These variations are due to the distribution of water salinity across
3969-611: Was escorted to Moscow to meet the Russian Tsar , Ivan IV . Returning from Russia in 1554, Chancellor brought back a detailed description of Moscow and the Russian north, which were largely unknown to Europe, as well as a letter from the Tsar expressing desire to establish trade relations with England. In 1555 Queen Mary issued a charter authorising the Muscovy Company to trade with Russia via
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