Pearl Organ
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Pearl Organ
Nuptial tubercles (also called nuptial efflorescences, breeding tubercles or pearl organs) are dermal structures present in 15 Family (biology), families of fish belonging to 4 orders of Actinopterygii – Salmoniformes, Gonorhynchiformes, Cypriniformes and Perciformes – used in the courtship and reproduction process. They consist of partially or fully keratinised Cell (biology), cells that form a perceptible protrusion in certain regions, used to stimulate females during courtship. Their development is stimulated by hormones secreted by the pituitary and adrenal glands, and is induced shortly before the breeding season and discarded after. In some species, at least, there is a correlation between the level of androgens present in the endocrine system and the volume and complexity of tubercle growth. Use and description Nuptial tubercles are skin nodules made of keratin, the same material as hair, hooves, and fingernails. They normally form on the heads of male fish, often co ...
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Keratin
Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, horns, claws, hooves, and the outer layer of skin among vertebrates. Keratin also protects epithelial cells from damage or stress. Keratin is extremely insoluble in water and organic solvents. Keratin monomers assemble into bundles to form intermediate filaments, which are tough and form strong unmineralized epidermal appendages found in reptiles, birds, amphibians, and mammals. Excessive keratinization participate in fortification of certain tissues such as in horns of cattle and rhinos, and armadillos' osteoderm. The only other biological matter known to approximate the toughness of keratinized tissue is chitin. Keratin comes in two types, the primitive, softer forms found in all vertebrates and harder, derived forms found only amon ...
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Hypertrophied
Hypertrophy is the increase in the volume of an organ or tissue due to the enlargement of its component cells. It is distinguished from hyperplasia, in which the cells remain approximately the same size but increase in number.Updated by Linda J. Vorvick. 8/14/1Hyperplasia/ref> Although hypertrophy and hyperplasia are two distinct processes, they frequently occur together, such as in the case of the hormonally-induced proliferation and enlargement of the cells of the uterus during pregnancy. Eccentric hypertrophy is a type of hypertrophy where the walls and chamber of a hollow organ undergo growth in which the overall size and volume are enlarged. It is applied especially to the left ventricle of heart. Sarcomeres are added in series, as for example in dilated cardiomyopathy (in contrast to hypertrophic cardiomyopathy, a type of concentric hypertrophy, where sarcomeres are added in parallel). Gallery File:*+ * Photographic documentation on sexual education - Hypertrophy of brea ...
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Loricariidae
The Loricariidae is the largest family of catfish (order Siluriformes), with 92 genera and just over 680 species. Loricariids originate from freshwater habitats of Costa Rica, Panama, and tropical and subtropical South America. These fish are noted for the bony plates covering their bodies and their suckermouths. Several genera are sold as " plecos", notably the suckermouth catfish, ''Hypostomus plecostomus'', and are popular as aquarium fish. Common names Members of the family Loricariidae are commonly referred to as loricariids, suckermouth armoured catfishes, or armoured catfish. The name "plecostomus", and its shortened forms "pleco" and "plec", are used for many Loricariidae, since ''Plecostomus plecostomus'' (now called ''Hypostomus plecostomus'') was one of the first loricariid species imported for the fish-keeping hobby. Some loricariids are not normally considered "plecostomus", such as ''Farlowella'' catfish. In their native range, these fish are known as ''cascudos'' ...
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Peixe Do Rio Madeira
Peixe is a municipality in the state of Tocantins in the Northern region of Brazil. See also *List of municipalities in Tocantins This is a list of the municipalities in the state of Tocantins (TO), located in the North Region of Brazil. Tocantins is divided into 139 municipalities, which are grouped into 8 microregions, which are grouped into 2 mesoregions. See al ... References Municipalities in Tocantins {{Tocantins-geo-stub ...
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Barbus
''Barbus'' is a genus of ray-finned fish in the family Cyprinidae. The type species of ''Barbus'' is the common barbel, first described as ''Cyprinus barbus'' and now named ''Barbus barbus''. ''Barbus'' is the namesake genus of the subfamily Barbinae, but given their relationships, that taxon is better included in the Cyprininae at least for the largest part (including the type species of ''Barbus''). Description and uses Their common names – barbs and barbels – refer to the fact that most members of the genera have a pair of barbels on their mouths, which they can use to search for food at the bottom of the water. Barbels are often fished for food; in some locations they are of commercial significance. The roe of barbels is poisonous, however. The large ''Barbus'' barbs are also often eaten in their native range. At Shanhûr in Egypt, remains of a jar from the sixth- to seventh-century AD were unearthed that contained fish bones. The fish were apparently pick ...
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Luciobarbus
''Luciobarbus'' is a genus of ray-finned fishes in the family Cyprinidae. Its members are found in fresh and brackish waters of southern Europe, northern Africa, the wider Near East, the Aral and Caspian Seas, and rivers associated with these. Several species in the genus are threatened. Most species are fairly small to medium-sized cyprinids, but the genus also includes several members that can surpass in length and the largest, the mangar (''L. esocinus'') can reach . Systematics The type species is ''Luciobarbus esocinus'', for which the genus was established by Heckel in 1843. The type species scientific name essentially means "pike-like pike-barbel" (after the northern pike, ''Esox lucius''), though a more aliteral translation would be "pike-like wolf-barbel". Like many other cyprinids, the present genus was long included in ''Barbus''. It appears to be a very close relative of the typical barbels – which include that genus type species, ''Barbus barbus'' –, ...
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Messinobarbus
''Barbus carottae'' is a species of ray-finned fish in the genus ''Barbus'' from Lake Yliki in Greece Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders with .... References * C Fish described in 1998 {{Barbus-stub ...
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Rutilus
''Rutilus'' is a genus of fish in the family Cyprinidae found in Eurasia. This genus is a widely distributed lineage of cyprinids and ranges from West Europe to East Siberia. Species In FishBase (2022), nine species are included in the genus: * ''Rutilus caspicus'' (Yakovlev, 1870) (Caspian roach) * ''Rutilus frisii'' ( Nordmann, 1840) (Black sea roach) * ''Rutilus heckelii'' (Nordmann, 1840) * ''Rutilus kutum'' (S. N. Kamensky, 1901) (Caspian kutum) * ''Rutilus meidingeri'' ( Heckel, 1851) * ''Rutilus pigus'' ( Lacépède, 1803) (Pigo) * '' Rutilus rutilus'' (Linnaeus, 1758) (Common roach) * ''Rutilus stoumboudae Bianco & Ketmaier, 2014 * ''Rutilus virgo'' ( Heckel, 1852) (Cactus roach) In a phylogeographic study, Levin et al. (2017) argue that the Ponto-Caspian taxa including ''R. caspicus'', ''R. heckelii'' and ''R. stoumboudae'' could represent a single widespread species whose range extends to Siberia, to be named ''Rutilus lacustris'', whereas ''R. kutum'' is included in ...
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Leucos
''Leucos'' is a genus of fishes in the family Cyprinidae, from Southern Europe. They are carp close to the genus '' Rutilus'', and were only recently taxonomically distinguished from that genus.Bianco, P.G., Ketmaier, V. (2014)A revision of the ''Rutilus'' complex from Mediterranean Europe with description of a new genus, ''Sarmarutilus'', and a new species, ''Rutilus stoumboudae'' (Teleostei: Cyprinidae).''Zootaxa'', 3841 (3): 379–402. Molecular data suggest that ''Leucos'' diverged from ''Rutilus'' more than five million years ago, probably during the Messinian salinity crisis. The species of ''Leucos'' are typically of small size and they all live in still waters. They differ from ''Rutilus'' by the lack of spinous tubercles on scales and head in reproductive males, and also in the pharyngeal teeth formula. The sister group to ''Leucos'' is the monotypic '' Sarmarutilus''. Species There are currently five recognized species in the genus:
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Papillomatosis
Papillomatosis of skin is skin surface elevation caused by hyperplasia and enlargement of contiguous dermal papillae.Kumar, Vinay; Fausto, Nelso; Abbas, Abul (2004) ''Robbins & Cotran Pathologic Basis of Disease'' (7th ed.). Saunders. Page 1230. . These papillary projections of the epidermis form an undulating surface under microscopic examination. See also * Skin lesion * Skin disease * List of skin diseases * Papilloma * Laryngeal papillomatosis Laryngeal papillomatosis, also known as recurrent respiratory papillomatosis (RRP) or glottal papillomatosis, is a rare medical condition in which benign tumors (papilloma) form along the aerodigestive tract. There are two variants based on the ag ... References External links {{Clinical and histological nomenclature for skin lesions Dermatologic terminology ...
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Lek Mating
A lek is an aggregation of male animals gathered to engage in competitive displays and courtship rituals, known as lekking, to entice visiting females which are surveying prospective partners with which to mate. A lek can also indicate an available plot of space able to be utilized by displaying males to defend their own share of territory for the breeding season. A lekking species is characterised by male displays, strong female mate choice, and the conferring of indirect benefits to males and reduced costs to females. Although most prevalent among birds such as black grouse, lekking is also found in a wide range of vertebrates including some bony fish, amphibians, reptiles, and mammals, and arthropods including crustaceans and insects. A classical lek consists of male territories in visual and auditory range of each other. An exploded lek, as seen in the kakapo (the owl parrot), has more widely separated territories, but still in auditory range. Lekking is associated with an ...
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