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Turritopsis Nutricula
''Turritopsis nutricula'' is a small hydrozoan that once reaching adulthood, can transfer its cells back to childhood. This adaptive trait likely evolved in order to extend the life of the individual. Several different species of the genus ''Turritopsis'' were formerly classified as ''T. nutricula'', including the " immortal jellyfish" which is now classified as '' T. dohrnii''. Life cycle Hydrozoans have two distinct stages in their life, a polyp stage and a medusa stage. The polyp stage is benthic, with the cells forming colonies, while the medusa stage is a singular, planktonic organism. Generally in hydrozoa the medusa develops from the asexual budding of the polyp and the polyp results from sexual reproduction of medusae. In ''T. nutricula'', planktonic medusa have the capability to bud polyps or medusae which also have the ability to spawn new medusae. Several nominal species have been described for this genus, but most of them had been synonymized and attributed to o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrozoan
Hydrozoa (hydrozoans; ) are a taxonomic class of individually very small, predatory animals, some solitary and some colonial, most of which inhabit saline water. The colonies of the colonial species can be large, and in some cases the specialized individual animals cannot survive outside the colony. A few genera within this class live in freshwater habitats. Hydrozoans are related to jellyfish and corals and belong to the phylum Cnidaria. Some examples of hydrozoans are the freshwater jelly (''Craspedacusta sowerbyi''), freshwater polyps ('' Hydra''), ''Obelia'', Portuguese man o' war (''Physalia physalis''), chondrophores (Porpitidae), "air fern" (''Sertularia argentea''), and pink-hearted hydroids (''Tubularia''). Anatomy Most hydrozoan species include both a polypoid and a medusoid stage in their lifecycles, although a number of them have only one or the other. For example, ''Hydra'' has no medusoid stage, while '' Liriope'' lacks the polypoid stage. Polyps The hydroid fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adaptation
In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the population during that process. Thirdly, it is a phenotypic trait or adaptive trait, with a functional role in each individual organism, that is maintained and has evolved through natural selection. Historically, adaptation has been described from the time of the ancient Greek philosophers such as Empedocles and Aristotle. In 18th and 19th century natural theology, adaptation was taken as evidence for the existence of a deity. Charles Darwin proposed instead that it was explained by natural selection. Adaptation is related to biological fitness, which governs the rate of evolution as measured by change in allele frequencies. Often, two or more species co-adapt and co-evolve as they develop adaptations that interlock with those of the oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turritopsis
''Turritopsis'' is a genus of hydrozoans in the family Oceaniidae. Species According to the ''World Register of Marine Species'', this genus includes the following species: * ''Turritopsis chevalense'' – ''species inquirenda'' * ''Turritopsis dohrnii'' also known as the " Benjamin Button jellyfish", or the "immortal jellyfish". It can reverse its life cycle and transform itself back to a polyp. * ''Turritopsis fascicularis'' * ''Turritopsis lata'' * ''Turritopsis minor'' * ''Turritopsis nutricula'' (several separate species, including the "immortal jellyfish", were formerly classified as ''T. nutricula'') * ''Turritopsis pacifica'' * ''Turritopsis pleurostoma'' – ''species inquirenda'' * ''Turritopsis polycirrha'' * ''Turritopsis rubra ''Turritopsis rubra,'' sometimes known as the crimson jelly, is a species of hydrozoan of the family Oceaniidae. Medusae of such species are informally called jellyfish. Description Adult medusae are energetic swimmers. They ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Immortality
Biological immortality (sometimes referred to as bio-indefinite mortality) is a state in which the rate of mortality from senescence is stable or decreasing, thus decoupling it from chronological age. Various unicellular and multicellular species, including some vertebrates, achieve this state either throughout their existence or after living long enough. A biologically immortal living being can still die from means other than senescence, such as through injury, poison, disease, predation, lack of available resources, or changes to environment. This definition of immortality has been challenged in the ''Handbook of the Biology of Aging'', because the increase in rate of mortality as a function of chronological age may be negligible at extremely old ages, an idea referred to as the late-life mortality plateau. The rate of mortality may cease to increase in old age, but in most cases that rate is typically very high. The term is also used by biologists to describe cells that are not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turritopsis Dohrnii
''Turritopsis dohrnii'', also known as the immortal jellyfish, is a species of small, biological immortality, biologically immortal jellyfish found worldwide in temperate to tropic waters. It is one of the few known cases of animals capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a solitary individual. Others include the jellyfish ''Laodicea undulata'' and species of the genus ''Aurelia (cnidarian), Aurelia''. Like most other hydrozoans, ''T. dohrnii'' begin their lives as tiny, free-swimming larvae known as planulae. As a planula settles down, it gives rise to a colony of polyp (zoology), polyps that are attached to the Seabed, sea floor. All the polyps and jellyfish arising from a single planula are genetically identical clones. The polyps form into an extensively branched form, which is not commonly seen in most jellyfish. Jellyfish, also known as medusae, then bud off these polyps and continue their life in a fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transdifferentiation
Transdifferentiation, also known as lineage reprogramming, is the process in which one mature somatic cell is transformed into another mature somatic cell without undergoing an intermediate pluripotent state or progenitor cell type. It is a type of metaplasia, which includes all cell fate switches, including the interconversion of stem cells. Current uses of transdifferentiation include disease modeling and drug discovery and in the future may include gene therapy and regenerative medicine. The term 'transdifferentiation' was originally coined by Selman and Kafatos in 1974 to describe a change in cell properties as cuticle producing cells became salt-secreting cells in silk moths undergoing metamorphosis. Discovery Davis et al. 1987 reported the first instance (sight) of transdifferentiation where a cell changed from one adult cell type to another. Forcing mouse embryonic fibroblasts to express MyoD was found to be sufficient to turn those cells into myoblasts. Natural examples ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceaniidae
Oceaniidae is one of the over 50 cnidarian families of the order Anthomedusae. It contains nearly 50 species in ten genera. Genera *'' Corydendrium'' (11 species) *'' Corystolona'' (monotypic) *'' Merona'' (5 species) *''Oceania'' (6 species) *''Pachycordyle'' (disputed) *'' Rhizogeton'' (7 species) *'' Similomerona'' (monotypic) *'' Tubiclava'' (5 species) *''Turritopsis ''Turritopsis'' is a genus of hydrozoans in the family Oceaniidae. Species According to the '' World Register of Marine Species'', this genus includes the following species: * '' Turritopsis chevalense'' – ''species inquirenda'' * ''Turrito ...'' (11 species) *'' Turritopsoides'' (monotypic) References Filifera Cnidarian families {{Anthoathecata-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animals Described In 1857
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and the deuterostomes, containing the echinoderms and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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