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Anthopleura Stellula
''Anthopleura stellula'' is a species of sea anemone in the family Actiniidae. It was first described in 1834 by Wilhelm Hemprich and Christian Gottfried Ehrenberg as ''Actinia (Isacmaea) stellula.'' It is found in the Indian Ocean and the Red Sea, and is unusual among sea anemones in that it can divide itself in two transversely. Biology ''Anthopleura stellula'' is unusual among sea anemones in that it can divide by transverse fission. This is not a common method of asexual reproduction among these sea anemones but tends to occur as a reaction to stress, such as when an anemone is experiencing a lowering of the salinity. The fission involves the animal forming a transverse constriction before dividing in two, the oral portion growing a new pedal disc and the basal portion growing a new oral disc and pharynx. There are a few other sea anemones such as '' Gonactinia prolifera'' that can divide in this way, and all are rather small, primitive sea anemones with simple internal struct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilhelm Hemprich
Wilhelm Friedrich Hemprich (24 June 1796 – 30 June 1825) was a German naturalist and explorer. Hemprich was born in Glatz (Kłodzko), Prussian Silesia, and studied medicine at Breslau and Berlin. It was in Berlin that he became friends with Christian Gottfried Ehrenberg, the two men sharing an interest in natural history. Hemprich lectured at Berlin University on comparative physiology, and wrote ''Grundriss der Naturgeschichte'' (Compendium of Natural History) (1820). In his spare time he studied reptiles and amphibians at the zoological museum under Hinrich Lichtenstein. In 1820 Hemprich and Ehrenberg were invited to serve as naturalists on a primarily archeological expedition to Egypt, led by Prussian General von Minutoli. The two naturalists were sponsored by the Berlin Academy. In March 1821 they separated from the main party and travelled up the river Nile to Dongola, the capital of Nubia. They spent the next two years studying the natural history of that part of Egy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christian Gottfried Ehrenberg
Christian Gottfried Ehrenberg (19 April 1795 – 27 June 1876) was a German naturalist, zoologist, comparative anatomist, geologist, and microscopist. Ehrenberg was an evangelist and was considered to be of the most famous and productive scientists of his time. Early collections The son of a judge, Christian Gottfried Ehrenberg was born in Delitzsch, near Leipzig. He first studied theology at the University of Leipzig, then medicine and natural sciences in Berlin and became a friend of the famous explorer Alexander von Humboldt. In 1818, he completed his doctoral dissertation on fungi, ''Sylvae mycologicae Berolinenses.'' In 1820–1825, on a scientific expedition to the Middle East with his friend Wilhelm Hemprich, he collected thousands of specimens of plants and animals. He investigated parts of Egypt, the Libyan Desert, the Nile valley and the northern coasts of the Red Sea, where he made a special study of the corals. Subsequently, parts of Syria, Arabia and Abyss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Anemone
Sea anemones are a group of predation, predatory marine invertebrates of the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia. As cnidarians, sea anemones are related to corals, jellyfish, tube-dwelling anemones, and ''hydra (genus), Hydra''. Unlike jellyfish, sea anemones do not have a Jellyfish#Life history and behavior, medusa stage in their life cycle. A typical sea anemone is a single polyp (zoology), polyp attached to a hard surface by its base, but some species live in soft sediment, and a few float near the surface of the water. The polyp has a columnar trunk topped by an oral disc with a ring of tentacles and a central mouth. The tentacles can be retracted inside the body cavity or expanded to catch passing prey. They are armed with cnidocytes (stinging cells). In many species, additional n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actiniidae
Actiniidae is the largest family of sea anemones, to which most common, temperate, shore species belong. Most members of this family do not participate in symbioses with fishes. Three exceptions are the bubble-tip anemone (with anemonefish and certain cardinalfish), snakelocks anemone (with Incognito goby) and ''Urticina piscivora'' (with painted greenling). The systematics of Actiniidae is often quite difficult. The problem with identification of genera within this family is that most species are readily distinguishable when alive but when fixated lose their color and some other features. Arrangement of tentacles is important in defining genera for Actiniaria families. There may be one tentacle per space between mesenteries or there may be more than one tentacle between each two mesenteries. Members of the family Actiniidae have one tentacle per space. Genera Genera in this family include: * ''Actinia'' Linnaeus, 1767 * '' Actinioides'' Haddon & Shackleton, 1893 * '' Actino ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asexual Reproduction
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the full set of genes of their single parent and thus the newly created individual is genetically and physically similar to the parent or an exact clone of the parent. Asexual reproduction is the primary form of reproduction for single-celled organisms such as archaea and eubacteria, bacteria. Many Eukaryote, eukaryotic organisms including plants, animals, and Fungus, fungi can also reproduce asexually. In vertebrates, the most common form of asexual reproduction is parthenogenesis, which is typically used as an alternative to sexual reproduction in times when reproductive opportunities are limited. Komodo dragons and some monitor lizards can also reproduce asexually. While all prokaryotes reproduce without the formation and fusion of gametes, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonactinia Prolifera
''Gonactinia'' is a monotypic genus of sea anemones, and ''G. prolifera'' is the only species in the genus. It is sometimes called the storey anemone and is found on either side of the northern Atlantic Ocean. Distribution and habitat ''Gonactinia prolifera'' is known from either side of the northern Atlantic Ocean including Maine and northwestern Europe, from the Mediterranean Sea, and the southern Pacific Ocean, including the coasts of New Zealand and Chile. Its natural habitat is on rocks, but it is also found on mollusc shells and large fronds of algae, from the fore-shore down to depths of about . Biology Like other sea anemones, ''G. prolifera'' is a predator, catching plankton with its tentacles. When a prey item is encountered, a rhythmic succession of reflex actions take place by which the food particle is passed by the tentacles to the mouth and then swallowed. Locomotion is by "walking" or swimming. The anemone walks by making a series of short, looping steps, first ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aulactinia Verrucosa
''Aulactinia verrucosa'', the gem anemone, is a species of sea anemone in the family Actiniidae. It is found on rocky coasts in the northeastern Atlantic Ocean, North Sea and Mediterranean Sea. Description ''Aulactinia verrucosa'' has a cylindrical body and is wider at the base than at the crown. The base is up to wide and the column tall. The walls of the column are covered by wart-like tubercles known as verrucae. Above the column, there are up to forty-eight tentacles, arranged in six cycles. The column is pink or grey, the tubercles grey or white, and the tentacles transparent and banded in pink, grey or olive. Distribution and habitat ''Aulactinia verrucosa'' is native to the northeastern Atlantic Ocean, the North Sea and the Mediterranean Sea. Its northern limit is Shetland and western Scotland and it is present all round the coasts of Ireland. It is found on rocky shores both in areas with strong currents and in calmer waters. It is present in crevices and in rock poo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animals Described In 1834
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] |
Taxa Named By Wilhelm Hemprich
In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were set forth in Carl Linnaeus's system in ''Systema Naturae'', 10th edition (1758), as well as an unpublished work by Bernard and Antoine Laurent de Jussieu. The idea of a unit-based system of biological classification was first made widely available in 1805 in the intro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
