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Tardigrade
Tardigrades (), known colloquially as water bears or moss piglets, are a phylum of eight-legged segmented micro-animals. They were first described by the German zoologist Johann August Ephraim Goeze in 1773, who called them . In 1776, the Italian biologist Lazzaro Spallanzani named them Tardigrada, which means 'slow walkers'. They live in diverse regions of Earth's biospheremountaintops, the deep sea, tropical rainforests, and the Antarctic. Tardigrades are among the most resilient animals known, with individual species able to survive extreme conditions – such as exposure to extreme temperatures, extreme pressures (both high and low), air deprivation, radiation, dehydration, and starvation – that would quickly kill most other forms of life. Tardigrades have survived exposure to outer space. There are about 1,500 known species in the phylum Tardigrada, a part of the superphylum Ecdysozoa. The earliest known fossil is from the Cambrian, some 500 million years ago ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tardigrade Anatomy
Tardigrades (), known colloquially as water bears or moss piglets, are a phylum of eight-legged Segmentation (biology), segmented micro-animals. They were first described by the German zoologist Johann August Ephraim Goeze in 1773, who called them . In 1776, the Italian biologist Lazzaro Spallanzani named them Tardigrada, which means 'slow walkers'. They live in diverse regions of Earth's biospheremountaintops, the deep sea, tropical rainforests, and the Antarctic. Tardigrades are among the most resilient animals known, with individual species able to survive extreme conditions – such as exposure to extreme temperatures, extreme pressures (both high and low), air deprivation, radiation, dehydration, and starvation – that would quickly kill most other forms of life. Tardigrades have survived exposure to outer space. There are about 1,500 known species in the phylum Tardigrada, a part of the superphylum Ecdysozoa. The earliest known fossil is from the Cambrian, some 500 m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milnesium Tardigradum
''Milnesium tardigradum'' is a cosmopolitan species of tardigrade that can be found in a diverse range of environments. It has also been found in the sea around Antarctica. ''M. tardigradum'' was described by Louis Michel François Doyère in 1840. It contains unidentified osmolytes that could potentially provide important information in the process of cryptobiosis. Description Morphology ''M. tardigradum'' has a symmetrical body with eight legs; it uses claws—a distinctive feature of this tardigrade species. The total length of the body varies, with some measuring up to 0.7 mm in length. ''M. tardigradum'' have been found to possess a high level of radioresistance. In 2007, individuals of two tardigrade species, '' Richtersius coronifer'' and ''M. tardigradum'', were subject to the radiation, near-vacuum, and near-absolute zero conditions of outer space as part of the European Space Agency's Biopan-6 experiment. Three specimens of ''M. tardigradum'' survived. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eutardigrade
Eutardigrada are a class of tardigrades (Tardigrada) without lateral appendages. Primarily freshwater bound, some species have secondarily gained the ability to live in marine environments ('' Halobiotus''). By cryptobiosis many species are able to live temporarily in very dry environments. More than 700 species have been described. The order Apochela consists of only one family, Milnesiidae, with two genera: '' Milnesium'' and '' Limmenius''. ''Milnesium tardigradum'' can be found worldwide and is one of the biggest species among tardigrades (up to 1.4 mm); similar-looking species have been found in Cretaceous amber. The mouth of this predator has a wide opening, so the animal can eat rotifers and larger protist A protist ( ) or protoctist is any eukaryotic organism that is not an animal, land plant, or fungus. Protists do not form a natural group, or clade, but are a paraphyletic grouping of all descendants of the last eukaryotic common ancest ...s. Other eu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterotardigrade
Heterotardigrades (class Heterotardigrada) is a class of the tardigrades (water bears) that have cephalic appendages and legs with four separate but similar digits or claws on each. 444 species have been described. Anatomy The anatomy of the reproductive system is an important defining feature in distinguishing the different groups of tardigrades. Heterotardigrades have gonoducts that open to the outside through a preanal gonopore, rather than opening into the rectum as in the Eutardigrada Eutardigrada are a class of tardigrades (Tardigrada) without lateral appendages. Primarily freshwater bound, some species have secondarily gained the ability to live in marine environments ('' Halobiotus''). By cryptobiosis many species are able .... Ecology Some orders of heterotardigrades are marine, others are terrestrial, but as for all tardigrades, all are aquatic in the sense that they must be surrounded by at least a film of moisture in order to be active – though they can s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecdysozoa
Ecdysozoa () is a group of protostome animals, including Arthropoda (insects, chelicerates (including arachnids), crustaceans, and myriapods), Nematoda, and several smaller phylum (biology), phyla. The grouping of these animal phyla into a single clade was first proposed by Eernisse ''et al.'' (1992) based on a phylogenetic analysis of 141 morphological characters of ultrastructural and embryological phenotypes. This clade, that is, a group consisting of a common ancestor and all its descendants, was formally named by Aguinaldo ''et al.'' in 1997, based mainly on phylogenetic trees constructed using 18S ribosomal RNA genes. A large study in 2008 by Dunn ''et al.'' strongly supported the monophyly of Ecdysozoa. The group Ecdysozoa is supported by many Morphology (biology), morphological characters, including growth by ecdysis, with moulting of the cuticle – without mitosis in the epidermis – under control of the prohormone ecdysone, and internal fertilization. The group was i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johann August Ephraim Goeze
Johann August Ephraim Goeze (; 28 May 1731 – 27 June 1793) was a German zoologist, born in Aschersleben. He is known for the discovery of tardigrades, also called water bears. He was the son of Johann Heinrich and Catherine Margarete (née Kirchhoff). He studied theology at University of Halle. He married Leopoldine Maria Keller in 1770, by whom he had four children. In 1751, he became a pastor in Aschersleben, in Quedlinburg, and later of in Quedlinburg in 1762, finally becoming first deacon of the seminary of Quedlinburg in 1787. He died in Quedlinburg. He did much work with aquatic invertebrates, particularly insects and worms. In 1784, Goeze perceived the similarities between the heads of tapeworms found in the human intestinal tract and the invaginated heads of '' Cysticercus cellulosae'' in pigs. In 1773, he was the first to describe tardigrades, naming them ''Kleiner Wasserbär'', meaning 'little water-bear'. Works *Goeze, J. A. E. 1776. Verzeichnisse der Namen von ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echiniscus
''Echiniscus'' is a genus of tardigrade Tardigrades (), known colloquially as water bears or moss piglets, are a phylum of eight-legged segmented micro-animals. They were first described by the German zoologist Johann August Ephraim Goeze in 1773, who called them . In 1776, th ...s in the family Echiniscidae. The genus was named and described by Karl August Sigismund Schultze in 1840. Species The genus includes the following species: * '' Echiniscus africanus'' Murray, 1907 * '' Echiniscus aliquantillus'' Grigarick, Schuster & Nelson, 1983 * '' Echiniscus angolensis'' da Cunha & do Nascimento Ribeiro, 1964 * '' Echiniscus apuanus'' Bertolani, 1946 * '' Echiniscus arcangelii'' Maucci, 1973–74 * '' Echiniscus arctomys'' Ehrenberg, 1853 * '' Echiniscus arthuri'' Pilato, Binda & Lisi, 2005 * '' Echiniscus azoricus'' Fontoura, Pilato & Lisi, 2008 * '' Echiniscus baius'' Marcus, 1928 * '' Echiniscus baloghi'' Iharos, 1973 * '' Echiniscus barbarae'' Kaczmarek & Micha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesotardigrada
Mesotardigrada is one of three classes of tardigrades, consisting of a single species, ''Thermozodium esakii''. The animal reportedly has six claws of equal length at each foot. This species was described in 1937 by German zoologist Gilbert Rahm from a hot spring near Nagasaki, Japan. The inability of taxonomists to replicate Rahm's finding has cast doubt on the accuracy of the description, making ''T. esakii'', and by extension the entire class Mesotardigrada, a ''taxon inquirendum''. Taxonomic ambiguity The type specimen Rahm used as the basis of his description has either been lost or it was never preserved in the first place, which Grothman ''et al''. (2017) suggest is consistent with the lax taxonomic standards of the 1930s. Thus, re-examination of the original specimen is not possible. Complicating matters further, the type locality from which Rahm collected his specimen may have been destroyed by an earthquake and subsequent searches for additional specimens matchin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micro-animal
Microfauna ( and ) are microscopic animals and organisms that exhibit animal-like qualities and have body sizes that are usually <0.1 mm. Microfauna are represented in the animal kingdom (e.g. s, small s) and some other heterotrophic, microscopic eukaryotes . A large amount of microfauna are soil microfauna which includes , rotifers, and nematodes. These types of animal-like eukaryotic microbes and true anima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homology (biology)
In biology, homology is similarity in anatomical structures or genes between organisms of different taxa due to shared ancestry, ''regardless'' of current functional differences. Evolutionary biology explains homologous structures as retained heredity from a common descent, common ancestor after having been subjected to adaptation (biology), adaptive modifications for different purposes as the result of natural selection. The term was first applied to biology in a non-evolutionary context by the anatomist Richard Owen in 1843. Homology was later explained by Charles Darwin's theory of evolution in 1859, but had been observed before this from Aristotle's biology onwards, and it was explicitly analysed by Pierre Belon in 1555. A common example of homologous structures is the forelimbs of vertebrates, where the bat wing development, wings of bats and origin of avian flight, birds, the arms of primates, the front flipper (anatomy), flippers of whales, and the forelegs of quadrupedalis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
