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Placozoan Range Map
Placozoa ( ; ) is a phylum of free-living (non-parasitic) marine invertebrates. They are blob-like animals composed of aggregations of cells. Moving in water by ciliary motion, eating food by engulfment, reproducing by fission or budding, placozoans are described as "the simplest animals on Earth." Structural and molecular analyses have supported them as among the most basal animals, thus, constituting a primitive metazoan phylum. The first known placozoan, ''Trichoplax adhaerens'', was discovered in 1883 by the German zoologist Franz Eilhard Schulze (1840–1921).F. E. Schulze "''Trichoplax adhaerens'' n. g., n. s.", ''Zoologischer Anzeiger'' (Elsevier, Amsterdam and Jena) 6 (1883), p. 92. Describing the uniqueness, another German, Karl Gottlieb Grell (1912–1994), erected a new phylum, Placozoa, for it in 1971. Remaining a monotypic phylum for over a century, new species began to be added since 2018. So far, three other extant species have been described, in two distinct cla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trichoplax Adhaerens
''Trichoplax adhaerens'' is one of the four named species in the phylum Placozoa. The others are ''Hoilungia hongkongensis'', ''Polyplacotoma mediterranea'' and ''Cladtertia collaboinventa''. Placozoa is a basal group of multicellular animals, possible relatives of Cnidaria. ''Trichoplax'' are very flat organisms commonly less than 4 mm in diameter, lacking any Organ (anatomy), organs or internal structures. They have two cellular layers: the top epitheloid layer is made of ciliated "cover cells" flattened toward the outside of the organism, and the bottom layer is made up of cylinder cells that possess Cilium, cilia used in locomotion, and gland cells that lack cilia. Between these layers is the fibre syncytium, a liquid-filled cavity strutted open by star-like fibres. ''Trichoplax'' feed by absorbing food particles—mainly microbes—with their underside. They generally Asexual reproduction, reproduce asexually, by Cell division, dividing or budding, but can also Sexual r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Budding
Budding or blastogenesis is a type of asexual reproduction in which a new organism develops from an outgrowth or bud due to cell division at one particular site. For example, the small bulb-like projection coming out from the yeast cell is known as a bud. Since the reproduction is asexual, the newly created organism is a clone and, excepting mutations, is genetically identical to the parent organism. Organisms such as hydra use regenerative cells for reproduction in the process of budding. In hydra, a bud develops as an outgrowth due to repeated cell division of the parent body at one specific site. These buds develop into tiny individuals and, when fully mature, detach from the parent body and become new independent individuals. Internal budding or endodyogeny is a process of asexual reproduction, favored by parasites such as '' Toxoplasma gondii''. It involves an unusual process in which two daughter cells are produced inside a mother cell, which is then consumed by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Francesco Saverio Monticelli
Francesco Saverio Monticelli (1863–1927) was an Italian zoologist at the Zoological Museum of Naples (curator from 1900). He was the taxonomic author of several families of parasites which are still recognized such as the Diplectanidae The Diplectanidae are a family of monopisthocotylean monogeneans. They are all parasitic on the gills of fish (marine or freshwater). Diplectanids are small animals, generally around 1 mm in length. As parasites, they can be extremely numero ... Monticelli, 1903 or the Plectanocotylidae Monticelli, 1903. Taxa named by Monticelli * Taxa named by Francesco Saverio Monticelli References * Monticelli, F.S. (1888) Saggio di una morfologia dei TrematodiGoogle Books* Monticelli, F.S. (1892) ''Cotylogaster'' Michaelis n g n sp. e revisione degli AspidobothridaeHathi Trust Digital Library* Monticelli, F.S. (1893) Studii sui Trematodi endoparassiti: Primo contributo di osservazioni sui distomidiPDF in BHL* Monticelli, F.S. (1903) Per una nuova c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HAL (open Archive)
HAL (short for ''Hyper Articles en Ligne'') is an open archive where authors can deposit scholarly documents from all academic fields. Documents in HAL are uploaded either by one of the authors with the consent of the others or by an authorized person on their behalf. An uploaded document does not need to have been published or even to be intended for publication. As an open access repository, HAL complies with the Open Archives Initiative (OAI-PMH) as well as with the European '' OpenAIRE'' project. HAL was started in 2001 by Franck Laloë, initially at École normale supérieure (ENS), and was later transferred to the (CCSD); other French institutions, such as Institute for Research in Computer Science and Automation (Inria), have joined the system. While it is primarily directed towards French academics, participation is not restricted to them. See also * List of preprint repositories This is a list of repositories used to store open science Open science is the mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graz, Austria
Graz () is the capital of the Austrian federal state of Styria and the second-largest city in Austria, after Vienna. On 1 January 2025, Graz had a population of 306,068 (343,461 including secondary residence). In 2023, the population of the Graz larger urban zone (LUZ) stood at 660,238. Graz is known as a city of higher education, with four colleges and four universities. Combined, the city is home to more than 60,000 students. Its historic centre (''Altstadt'') is one of the best-preserved city centres in Central Europe. In 1999, the city's historic centre was added to the UNESCO list of World Heritage Sites and in 2010 the designation was expanded to include Eggenberg Palace () on the western edge of the city. Graz was designated the Cultural Capital of Europe in 2003 and became a City of Culinary Delights in 2008. In addition, the city is recognized as a " Design City" by UNESCO's Creative Cities Network. Etymology The name of the city, Graz, formerly spelled Gratz and also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maculicorpus Microbialis
''Maculicorpus'' is a genus of fossil placozoan from the Middle Triassic of Germany, and the first placozoan known from the fossil record. It comprises a single known species, ''Maculicorpus microbialis''. Discovery ''Maculicorpus'' is known from a microbialite bed discovered in the Troistedt Quarry near Weimar, as part of the Meißner Formation. The microbialite has been dated to the late Anisian to early Ladinian The Ladinian is a stage and age in the Middle Triassic series or epoch. It spans the time between Ma and ~237 Ma (million years ago). The Ladinian was preceded by the Anisian and succeeded by the Carnian (part of the Upper or Late Triassic .... Description The specimens referred to ''Maculicorpus'' appear as flat patches, brown to ochre in color, varying between and in diameter. The outline is irregular and varies in overall shape from circular to elongate, fan-shaped or multi-lobed. The holotype, in length, is constricted in the middle, appearing as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Triassic
In the geologic timescale, the Middle Triassic is the second of three epoch (geology), epochs of the Triassic period (geology), period or the middle of three series (stratigraphy), series in which the Triassic system (stratigraphy), system is divided in chronostratigraphy. The Middle Triassic spans the time between annum, Ma and Ma (million years ago). It is preceded by the Early Triassic Epoch and followed by the Late Triassic Epoch. The Middle Triassic is divided into the Anisian and Ladinian age (geology), ages or stage (stratigraphy), stages. Formerly the middle series in the Triassic was also known as Muschelkalk. This name is now only used for a specific unit of stratum, rock strata with approximately Middle Triassic age, found in western Europe. Middle Triassic life Following the Permian–Triassic extinction event, the most devastating of all mass-extinctions, life recovered slowly. In the Middle Triassic, many groups of organisms reached higher diversity again, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyplacotoma Mediterranea
''Polyplacotoma mediterranea'' is a species in the phylum Placozoa, only representative of the genus ''Polyplacotoma'', and was discovered in the Mediterranean Sea The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern Eur .... They differ greatly from other species of placozoans with regards to their morphology and genetic makeup, and have been ranked in the separate class Polyplacotomia. ''P. mediterranea'' has the smallest mitogenome, the lowest GC content, and the smallest intergenic spacer regions of all placozoans. Their bodily structure consists of elongated polytomous body branches, as well as a maximum size that is greater than 10 mm in length. They have also been observed having a diet of algae. The mitochondrial genome of ''Polyplacotoma mediterranea'' is also very compact and cont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladtertia Collaboinventa
''Cladtertia'' is a genus of placozoan discovered in 2022. The genus contains a single described species, ''Cladtertia collaboinventa'', although several other undescribed lineages are known. Its closest described relative is '' Hoilungia hongkongensis'', with whom it forms the order Hoilungea. ''Cladtertia'' is similar in morphology to most other placozoans, but genetically distinct from them. It has been found in warm tropical waters with low seasonal changes, ranging from 26°N to 25°S, where it occupies a distinct ecological niche compared to other placozoan lineages. Sexual reproduction through cross-fertilization has been observed in a strain of ''Cladtertia''. Etymology The genus name comes from Ancient Greek ''kládos'' (clade) and Latin ''tertius'' (the third), referring to its specimens previously being assigned to placozoan Clade III in literature. Biology ''Cladtertia'' is morphologically indistinguishable under light microscopy from other placozoans in the cla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hoilungia Hongkongensis
''Hoilungia'' is a genus that contains one of the simplest animals and belongs to the phylum Placozoa. Described in 2018, it has only Monotypic taxon, one named species, ''H. hongkongensis'', although there are possible other species. The animal superficially resembles another placozoan, ''Trichoplax adhaerens'', but genetically distinct from it as mitochondrial DNA analysis revealed. ''Hoilungia'' was discovered in brackish water from mangrove swamps in Hong Kong. These organisms are generally found in the biofilm surfaces in tropical and subtropical environments. Phylogenetically, they are placed closest to cnidarians. They are diploblastic animals and are believed to have dorso-ventral polarity along top and bottom body layers. Their body is overtly similar to oral-aboral axis of cnidarians. Discovery ''Trichoplax adhaerens'' was discovered by the German zoologist Franz Eilhard Schulze in 1883. But its identification as to what kind of animal it was (systematic position) was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Current Biology
''Current Biology'' is a biweekly peer-reviewed scientific journal that covers all areas of biology, especially molecular biology, cell biology, genetics, neurobiology, ecology, and evolutionary biology. The journal includes research articles, various types of review articles, as well as an editorial magazine section. The journal was established in 1991 by the Current Science group, was acquired by Elsevier in 1998, and has since 2001 been part of Cell Press, a subdivision of Elsevier. According to '' Journal Citation Reports'', the journal has a 2020 impact factor of 10.834. It was categorized as a "high impact journal" by the Superfund Research Program. References External links * Biology journals English-language journals Cell Press academic journals Academic journals established in 1991 Biweekly journals {{biology-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. Theoretical implications Monotypic taxa present several important theoretical challenges in biological classification. One key issue is known as "Gregg's Paradox": if a single species is the only member of multiple hierarchical levels (for example, being the only species in its genus, which is the only genus in its family), then each level needs a distinct definition to maintain logical structure. Otherwise, the different taxonomic ranks become effectively identical, which creates problems for organizing biological diversity in a hierarchical syste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
