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Chaoborus Abundans
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midges or lake flies. Appearance Glassworms are almost entirely transparent, except for pairs of black kidney-shaped structures in the front and the back of the body. These dots are the air sacs. They use these air sacs to migrate up and down in lakes. Glassworms breathe through the end of their abdomen and have two small eyes at the front of their bodies. Behavior ''Chaoborus'' adults do not bite mammals or suck blood. Larvae live in open waters and even sediments, where there may be little oxygen for them to breathe. In some lakes they can be found as deep as . In these deep anoxic waters they can avoid predation more easily than near the surface. They get around the fact that a normal air filled invertebrate tracheal system would fail at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anton August Heinrich Lichtenstein
Anton August Heinrich Lichtenstein (25 August 1753, Helmstedt – 17 February 1816, Helmstedt) was a German zoologist. He was the father of Martin Lichtenstein, Martin Hinrich Carl Lichtenstein (1780–1857). He studied theology, philosophy, natural history and Oriental studies in Helmstadt, Göttingen and Leipzig, and from 1782 onwards, was rector (academia), rector of the Gelehrtenschule des Johanneums, Johanneum in Hamburg. In 1794, he also took on the job of city librarian. Later, he relocated to the University of Helmstedt, where he served as a professor of theology (1798–1810) and Greek language (1804–1810). He was the author of ''Catalogus Rerum Naturalium Rarissimarum'' (1793) and ''Catalogus Musei zoologici ditissimi Hamburgi'' (1796), and contributed to Johann Friedrich Wilhelm Herbst's ''Natursystem der ungeflügelten Insekten'' (1797). [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladocerans
The Diplostraca or Cladocera, commonly known as water fleas, is a superorder (biology), superorder of small, mostly freshwater crustaceans, most of which feed on microscopic chunks of organic matter, though some forms are predatory. Over 1000 species have been recognised so far, with many more undescribed species, undescribed. The oldest fossils of diplostracans date to the Jurassic, though their modern morphology suggests that they originated substantially earlier, during the Paleozoic. Some have also adapted to a life in the ocean, the only members of Branchiopoda to do so, though several anostracans live in hypersaline lakes. Most are long, with a down-turned head with a single median compound eye, and a carapace covering the apparently unsegmented Crustacean#Structure, thorax and abdomen. Most species show cyclical parthenogenesis, where asexual reproduction is occasionally supplemented by sexual reproduction, which produces resting eggs that allow the species to survive hars ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Food
Aquarium fish feed is plant or animal material intended for consumption by pet fish kept in aquariums or ponds. Fish foods normally contain macronutrients, trace elements and vitamins necessary to keep captive fish in good health. Approximately 80% of fishkeeping hobbyists feed their fish exclusively prepared foods that most commonly are produced in flake, pellet or tablet form. Some fish foods also contain additives such as sex hormones or beta carotene to artificially enhance the color of ornamental fish. Prepared foods Prepared foods are those foods that are non-living and are made by the aquarist or bought already prepared for consumption for fish. Dry foods Dry food is a type of proprietary or artificially manufactured fish food consumed by a wide variety of tropical and saltwater fish and invertebrates. It is ideally suited to top dwellers and mid-water fish though numerous bottom dwelling species consume flake food once it has settled on the bottom. Flake food is baked ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorine
Chlorine is a chemical element; it has Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is a yellow-green gas at room temperature. It is an extremely reactive element and a strong oxidizing agent, oxidising agent: among the elements, it has the highest electron affinity and the third-highest electronegativity on the revised Electronegativity#Pauling electronegativity, Pauling scale, behind only oxygen and fluorine. Chlorine played an important role in the experiments conducted by medieval Alchemy, alchemists, which commonly involved the heating of chloride Salt (chemistry), salts like ammonium chloride (sal ammoniac) and sodium chloride (common salt), producing various chemical substances containing chlorine such as hydrogen chloride, mercury(II) chloride (corrosive sublimate), and . However, the nature of fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plankton Net
A plankton net is equipment used for collecting Sampling method, samples of plankton in standing bodies of water. It consists of a towing line and bridles, nylon mesh net, and a cod end. Plankton nets are considered one of the oldest, simplest and least expensive methods of sampling plankton. The plankton net can be used for both vertical and horizontal sampling. It allows researchers to analyse plankton both quantitative research, quantitatively (cell density, cell colony or biomass) and qualitative property, qualitatively (e.g. Chlorophyll-a as a primary production of phytoplankton) in water samples from the environment. Components ; Towing line and bridle : The towing line and bridle is the upper part of a plankton net and used to hold it. The towing lines connected to the triangle bridles are made of nylon rope and can be adjust to a level suitable for the user. ; Nylon mesh net : The nylon mesh net (device), net is the middle part of the plankton net and is used to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chaoborus Punctipennis P1290021a
''Chaoborus'' is a genus of midges in the family Chaoboridae. The larvae are known as glassworms because they are transparent. They can be found commonly in lakes all over the world and can be up to . The adults are sometimes called phantom midges or lake flies. Appearance Glassworms are almost entirely transparent, except for pairs of black kidney-shaped structures in the front and the back of the body. These dots are the air sacs. They use these air sacs to migrate up and down in lakes. Glassworms breathe through the end of their abdomen and have two small eyes at the front of their bodies. Behavior ''Chaoborus'' adults do not bite mammals or suck blood. Larvae live in open waters and even sediments, where there may be little oxygen for them to breathe. In some lakes they can be found as deep as . In these deep anoxic waters they can avoid predation more easily than near the surface. They get around the fact that a normal air filled invertebrate tracheal system would fail at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Generation Time
In population biology and demography Demography () is the statistical study of human populations: their size, composition (e.g., ethnic group, age), and how they change through the interplay of fertility (births), mortality (deaths), and migration. Demographic analysis examine ..., generation time is the average time between two consecutive generations in the lineages of a population. In human populations, generation time typically has ranged from 20 to 30 years, with wide variation based on gender and society. Historians sometimes use this to date events, by converting generations into years to obtain rough estimates of time. Definitions and corresponding formulas The existing definitions of generation time fall into two categories: those that treat generation time as a renewal time of the population, and those that focus on the distance between individuals of one generation and the next. Below are the three most commonly used definitions: Time for a population to gro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Livingstone
David Livingstone (; 19 March 1813 – 1 May 1873) was a Scottish physician, Congregationalist, pioneer Christian missionary with the London Missionary Society, and an explorer in Africa. Livingstone was married to Mary Moffat Livingstone, from the prominent 18th-century Moffat missionary family. Livingstone came to have a mythic status as a Protestant missionary martyr, working-class " rags-to-riches" inspirational story, scientific investigator and explorer, imperial reformer, anti-slavery crusader, and advocate of British commercial and colonial expansion. As a result, he became one of the most popular British heroes of the late 19th-century Victorian era. Livingstone's fame as an explorer and his obsession with learning the sources of the Nile was founded on the belief that if he could solve that age-old mystery, his fame would give him the influence to end the East African Arab–Swahili slave trade. "The Nile sources", he told a friend, "are valuable only as a m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metabolic reactions, DNA replication, Cell signaling, responding to stimuli, providing Cytoskeleton, structure to cells and Fibrous protein, organisms, and Intracellular transport, transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the Nucleic acid sequence, nucleotide sequence of their genes, and which usually results in protein folding into a specific Protein structure, 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called pep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kunga Cake
Kunga cake or kungu is a food dish made of densely compressed midges or flies. It is found in the African Great Lakes region, specifically countries surrounding Lake Malawi (Tanzania, Malawi, and Mozambique). May Berenbaum, an American entomologist, discusses how swarms of midges can cause significant problems for local populations. She cites an example of swarms of '' Chaoborus edulis'', a species of midge, forming near Lake Malawi and how the local people turn them into kunga cakes as a "rich source of protein", which is eaten "with great enthusiasm". To catch the flies, a frying pan can be coated in cooking oil and then wafted through a swarm. In ''Insects: An Edible Field Guide'', a book on the consumption of insects, author Stefan Gates suggests that people can "make burgers with it, or dry it out and grate parts of it off into stews" for "umami richness". Adventurer Bear Grylls calls kunga cake "a great survival food". Explorer David Livingstone David Livingstone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Tanganyika
Lake Tanganyika ( ; ) is an African Great Lakes, African Great Lake. It is the world's List of lakes by volume, second-largest freshwater lake by volume and the List of lakes by depth, second deepest, in both cases after Lake Baikal in Siberia. It is the world's longest freshwater lake. The lake is shared among four countries—Tanzania, the Democratic Republic of the Congo (the DRC), Burundi, and Zambia—with Tanzania (46%) and the DRC (40%) possessing the majority of the lake. It drains via the Lukuga River into the Congo River system, which ultimately discharges at Banana, Democratic Republic of the Congo into the Atlantic Ocean. Geography Lake Tanganyika is situated within the Albertine Rift, the western branch of the East African Rift, and is confined by the mountainous walls of the valley. It is the largest rift lake in Africa and the second-largest freshwater lake by volume in the world. It is the deepest lake in Africa and holds the greatest volume of fresh water on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Victoria
Lake Victoria is one of the African Great Lakes. With a surface area of approximately , Lake Victoria is Africa's largest lake by area, the world's largest tropics, tropical lake, and the world's second-largest fresh water lake by surface area after Lake Superior in North America. In terms of volume, Lake Victoria is the world's list of lakes by volume, ninth-largest continental lake, containing about of water. Lake Victoria occupies a shallow Depression (geology), depression in Africa. The lake has an average depth of and a maximum depth of .United Nations, ''Development and Harmonisation of Environmental Laws Volume 1: Report on the Legal and Institutional Issues in the Lake Victoria Basin'', United Nations, 1999, page 17 Its drainage basin, catchment area covers . The lake has a shoreline of when digitized at the 1:25,000 level, with islands constituting 3.7% of this length. The lake's area is divided among three countries: Tanzania occupies 49% (), Uganda 45% (), and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
