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Pseudoscaphirhynchus Kaufmanni
The Amu Darya sturgeon or false shovelnose sturgeon (''Pseudoscaphirhynchus kaufmanni'') is a critically endangered species of fish in the family (biology), family Acipenseridae. It is found in Turkmenistan, Uzbekistan, Tajikistan and perhaps Afghanistan. It inhabits quite shallow flowing waters that are turbid and muddy.Birstein, V.J.; J.R. Waldman; and W.E. Bemis, editors (1997). Sturgeon biodiversity and conservation, pp. 377–378, 381–382. Kluwer Academic Publishing. Appearance The Amu Darya sturgeon is a small sturgeon, but the largest species of ''Pseudoscaphirhynchus'', reaching up to in weight and in total length, excluding tail filament. It has a long, thin tail filament. For example, two individuals that both had a length of about excluding tail filament were and including tail filament. The species occurs in two Polymorphism (biology), morphs: a relatively large, light-coloured and late maturing morph, and a small, dark-coloured and early maturing morph. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karl Fedorovich Kessler
Karl Fedorovich Kessler (; – ) was a Baltic German zoologist who worked as a professor of biology at Saint Petersburg Imperial University. Among his contributions was the idea that evolution at an infraspecific level involved mutual aid and that Charles Darwin had placed too much emphasis on competition which he accepted as occurring at the interspecies level. Life and work Kessler was born in Damrau, Königsberg, Konigsberg, where his father was a royal forester (''oberforestmeister''). His father moved to Novgorod Governorate, where Kessler grew up. In 1828, he joined the with a scholarship and went to Saint Petersburg Imperial University in 1834. He attended the zoology lectures of Stepan Kutorga. After graduation he worked as a school mathematics teacher. In 1837, Kessler and his botanist friend from student days, went on an expedition to Finland. In 1840, he defended a master's dissertation on the legs of birds in relation to systematics. In 1842, his doctoral di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kerki
Kerki is a city in and capital of Kerki District, Lebap Province, Turkmenistan. It was formerly known as Zamm and, between 1999 and 2017, as Atamyrat. Geography It is situated on a plain on the left bank of the Amu Darya river. Nearby towns and villages include Mukry (3.3 nm), Amydarýa (2.1 nm), Surhy (3.1 nm) and Kerkichi (2.2 nm). Climate Etymology According to Atanyyazow, the name Kerki is most likely of Persian origin, from ''ker'' ("fortress") and ''kuh'' ("mountain"), meaning "fortress on a mountain". However, Muqaddasī and de Goeje assert it is a Turkified pronunciation of the Persian name Karkuh (کرکوه), meaning "deaf mountain". The ancient name, Zamm, is of obscure origin. On 29 December 1999, by Parliamentary Resolution HM-60, the city and district of Kerki were renamed Atamyrat in honor of Atamyrat Nyýazow, father of Saparmurat Niyazov, who had worked in Kerki as a teacher before being killed in World War II. On 25 November 2017, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scaphirhynchinae
Sturgeon (from Old English ultimately from Proto-Indo-European *''str̥(Hx)yón''-) is the common name for the 27 species of fish belonging to the family Acipenseridae. The earliest sturgeon fossils date to the Late Cretaceous, and are descended from other, earlier acipenseriform fish, which date back to the Early Jurassic period, some 174 to 201 million years ago. They are one of two living families of the Acipenseriformes alongside paddlefish (Polyodontidae). The family is grouped into five genera: ''Acipenser'', ''Huso'', ''Scaphirhynchus,'' '' Sinosturio'', and '' Pseudoscaphirhynchus''. Two species ('' H. naccarii'' and '' S. dabryanus'') may be extinct in the wild, and one ('' P. fedtschenkoi'') may be entirely extinct. Sturgeons are native to subtropical, temperate and sub-Arctic rivers, lakes and coastlines of Eurasia and North America. A Maastrichtian-age fossil found in Morocco shows that they also once lived in northern Africa during the Cretaceous. Sturgeons are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shovelnose Sturgeon
The shovelnose sturgeon (''Scaphirhynchus platorynchus'') is the smallest species of freshwater sturgeon native to North America. It is often called hackleback, sand sturgeon, or switchtail. Switchtail refers to the long filament found on the upper lobe of the caudal fin (often broken off as adults). Shovelnose sturgeon are the most abundant sturgeon found in the Missouri River and Mississippi River systems, and were formerly a commercially fished sturgeon in the United States of America (Pflieger 1997). In 2010, they were listed as threatened under the U.S. Endangered Species Act due to their resemblance to the endangered pallid sturgeon (''S. albus''), with which shovelnose sturgeon are sympatric. Description The sturgeons of the family Acipenseridae have bony scutes along the sides and back and four barbels on the underside of the rostrum. A total of 25 extant species of sturgeon are recognized, including 17 within the genus ''Acipenser''. Sturgeon are distributed around t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetics
Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinians, Augustinian friar working in the 19th century in Brno, was the first to study genetics scientifically. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring over time. He observed that organisms (pea plants) inherit traits by way of discrete "units of inheritance". This term, still used today, is a somewhat ambiguous definition of what is referred to as a gene. Phenotypic trait, Trait inheritance and Molecular genetics, molecular inheritance mechanisms of genes are still primary principles of genetics in the 21st century, but modern genetics has expanded to study the function and behavior of genes. Gene structure and function, variation, and distribution are studied within the context of the Cell (bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome
A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most important of these proteins are the histones. Aided by chaperone proteins, the histones bind to and condense the DNA molecule to maintain its integrity. These eukaryotic chromosomes display a complex three-dimensional structure that has a significant role in transcriptional regulation. Normally, chromosomes are visible under a light microscope only during the metaphase of cell division, where all chromosomes are aligned in the center of the cell in their condensed form. Before this stage occurs, each chromosome is duplicated ( S phase), and the two copies are joined by a centromere—resulting in either an X-shaped structure if the centromere is located equatorially, or a two-armed structure if the centromere is located distally; the jo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karyotype
A karyotype is the general appearance of the complete set of chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is discerned by determining the chromosome complement of an individual, including the number of chromosomes and any abnormalities. A karyogram or idiogram is a graphical depiction of a karyotype, wherein chromosomes are generally organized in pairs, ordered by size and position of centromere for chromosomes of the same size. Karyotyping generally combines light microscopy and photography in the metaphase of the cell cycle, and results in a photomicrographic (or simply micrographic) karyogram. In contrast, a schematic karyogram is a designed graphic representation of a karyotype. In schematic karyograms, just one of the sister chromatids of each chromosome is generally shown for brevity, and in reality they are generally so close together that they look as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Stocking
Fish stocking is the practice of releasing fish that are artificially raised in a fish hatchery, hatchery into a natural body of water (river, lake, or ocean), to supplement existing wild populations or to create a new population where previously none exists. Stocking may be done for the benefit of commercial fishing, commercial, recreational fishing, recreational or tribal artisan fishing, heritage fishing, but may also be done for ecological conservation to restore or increase the population of threatened species, threatened/endangered species, endangered fish species that is pressured by prior overfishing, habitat destruction, and/or competition (biology), competition from invasive species. Fish stocking may be conducted by governmental fisheries management agencies, non-profit organizations, and voluntary associations in public waters, or by for-profit corporation, for-profit NGOs, clubs and commercial enterprises in privately owned waters. When in public waters, fish stocking ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CITES Appendix II
CITES (shorter acronym for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of international trade. It was drafted as a result of a resolution adopted in 1963 at a meeting of members of the International Union for Conservation of Nature (IUCN). The convention was opened for signature in 1973 and CITES entered into force on 1 July 1975. Its aim is to ensure that international trade (import/export) in specimens of animals and plants included under CITES does not threaten the survival of the species in the wild. This is achieved via a system of permits and certificates. CITES affords varying degrees of protection to more than 40,900 species. , the Secretary-General of CITES is Ivonne Higuero. Background CITES is one of the largest and oldest conservation and sustainable use agreements in existence. There are three working ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Illegal, Unreported And Unregulated Fishing
Illegal, unreported and unregulated fishing (IUU) is an issue around the world. Fishing industry observers believe IUU occurs in most fisheries, and accounts for up to 30% of total catches in some important fisheries. Illegal fishing takes place when vessels or harvesters operate in violation of the laws of a fishery. This can apply to fisheries that are under the jurisdiction of a coastal state or to high seas fisheries regulated by regional fisheries management organisations (RFMO). According to the UN Food and Agriculture Organization (FAO), Fisheries and Aquaculture Department, illegal fishing has caused losses estimated at US$23 billion per year. Unreported fishing is fishing that has been unreported or misreported to the relevant national authority or RFMO, in contravention of applicable laws and regulations. Unregulated fishing generally refers to fishing by vessels without nationality, vessels flying the flag of a country not party to the RFMO governing that fishing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amudarya State Nature Reserve
Amyderýa Nature Reserve () is a nature reserve (''zapovednik'') of north-eastern Turkmenistan. Established in 1982 to protect part of the Amu Darya River, it is located in the north-east of Lebap Province Lebap Region () is one of the regions of Turkmenistan. It is in the northeast of the country, bordering Afghanistan, Uzbekistan along the Amu Darya. Its administrative centre is Türkmenabat (formerly named Çärjew). It has an area of 93,727 s ... and covers an area of 495 km2. It also incorporates one sanctuary: * Kelif Sanctuary - established in 1970. References *''National Program for the Protection of the Environment'', Ashgabat, 2002, pp. 149–151 External links Amudarya State Nature Reserve on Nature Protection Nature reserves in Turkmenistan Protected areas established in 1982 World Heritage Tentative List 1982 establishments in the Turkmen Soviet Socialist Republic {{Asia-protected-area-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syr Darya Sturgeon
The Syr Darya sturgeon (''Pseudoscaphirhynchus fedtschenkoi''), or Syr Darya shovelnose sturgeon, is a species of fish in the family Acipenseridae. It is found in Kazakhstan, Tajikistan and Uzbekistan, where it is Endemism, endemic to the Syr Darya River and, before its drainage, the Aral Sea. Due to the loss of its breeding site and damming projects over the length of the river, it is currently considered Critically Endangered (Possibly Extinct), as no sightings have been reported since the 1960s. The sturgeon is among the 25 "most wanted lost" species that are the focus of Re:wild's "Search for Lost Species" initiative. Taxonomy The Syr Darya sturgeon belongs to the genus Pseudoscaphirhynchus, which is a genus of sturgeon that are restricted to the Aral Sea systems. A study of the mitochondrial DNA of the members of the genus conducted published in 2020 showed that the genus is monophyletic, and that the two other species in the genus are more closely related to each other th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
