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Oreochromis Amphimelas
''Oreochromis amphimelas'' is a species of tilapia cichlid endemic to north–central Tanzania, where it is found in Lake Manyara and a number of other saline lakes with closed basins. Maximum recorded size is in standard length. Description This is an unusual-looking tilapia: the front part of the head is very short, so it has a small eye, small mouth and short snout. The smaller fish have a rather cylindrical body, but the largest fish have a high, arched back and a concave head profile. The mouth is quite upwardly-angled. The gill arches hold relatively few gill rakers: only 12–16 on the lower part of the outermost arch, the arches lack microbranchiospines and the number of dorsal fin spines is only 12–14, which is rather low compared to other ''Oreochromis''. Females and immatures are a silvery grey, but show little sign of vertical bars on the flanks or a 'tilapia mark' at the base of the soft dorsal fin shown by most other tilapias. Mature males are dark pinkish with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Franz Martin Hilgendorf
Franz Martin Hilgendorf (5 December 1839 – 5 July 1904) was a German zoologist and paleontologist. Hilgendorf's research on fossil snails from the Steinheim crater in the early 1860s became a palaeontological evidence for the theory of evolution published by Charles Darwin in 1859. Life and work Franz Hilgendorf was born on 5 December 1839 in Neudamm (Mark Brandenburg). Between 1851 and 1854 he went to a gymnasium in Königsberg (Neumark) and later to the Gymnasium ''Zum Grauen Kloster'' (Grey Monastery) in Berlin where he graduated in 1858. In 1859 he started studying philology at the University of Berlin. After four semesters he changed to the University of Tübingen. In the summer of 1862 he joined an excavation by Friedrich August Quenstedt in the Steinheim crater. In 1863 Hilgendorf received his Ph.D. for work related to this excavation. He finished his research on the fossils during his time at the Museum für Naturkunde in Berlin. In 1868, Hilgendorf became ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethelwynn Trewavas
Ethelwynn Trewavas (5 November 1900 – 16 August 1993) was an ichthyologist at the British Museum of Natural History. She was known for her work on the families Cichlidae and Sciaenidae. She worked with Charles Tate Regan, another ichthyologist and taxonomist. Academic studies and career She received her bachelor's degree and Board of Education Certificate in Teaching in 1921 from Reading University, and then worked as a teacher before being employed by the King's College of Household and Social Science as a part-time demonstrator, spending most of her time on research. She was taught by Dr. Nellie B. Eales when associated with the Freshwater Biological Association. She met Charles Regan and was employed by him as his assistant until hired by the British Museum (Natural History) as Assistant Keeper in 1935. She was appointed Deputy Keeper of Zoology in 1958, and retired in 1961. She served as the senior scientist in the Fish Section of the British Museum (Natural Histo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hybrid (biology)
In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different breeds, varieties, species or genera through sexual reproduction. Hybrids are not always intermediates between their parents (such as in blending inheritance), but can show hybrid vigor, sometimes growing larger or taller than either parent. The concept of a hybrid is interpreted differently in animal and plant breeding, where there is interest in the individual parentage. In genetics, attention is focused on the numbers of chromosomes. In taxonomy, a key question is how closely related the parent species are. Species are reproductively isolated by strong barriers to hybridisation, which include genetic and morphological differences, differing times of fertility, mating behaviors and cues, and physiological rejection of sperm cells or the developing embryo. Some act before fertilization and others after it. Similar barriers exist in plants, with differences in flowering tim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coptodon
''Coptodon'' is a genus of cichlids native to fresh, brackish and coastal marine waters in Africa with ''C. zillii'' also found in the Middle East. It is the only genus in the tribe Coptodonini. Formerly included in ''Tilapia'', this genus and tribe was separated in 2013.Dunz, A.R. & Schliewen, U.K. (2013): Molecular phylogeny and revised classification of the haplotilapiine cichlid fishes formerly referred to as ''“Tilapia”''. ''Molecular Phylogenetics and Evolution, Available online 29 March 2013 doi: 10.1016/j.ympev.2013.03.015'' Despite the change in genus, ''Coptodon'' spp. are still referred to by the common name tilapia. Several species are important in local fisheries and a few are aquacultured. Appearance Depending on the exact species, the maximum length of ''Coptodon'' ranges from ; the smallest is ''C. snyderae'', which also is the smallest tilapia. Although the individual species typically have different nonbreeding and breeding colors, the sexes are alike. Some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oreochromis Leucostictus
''Oreochromis leucostictus'' (the blue-spotted tilapia) is a species of cichlid native to Albertine Rift Valley lakes and associated rivers in DR Congo and Uganda. It has now been introduced widely elsewhere East Africa, and is believed to have negative ecological impact, particularly on native tilapias. This species is reported to reach a standard length of up to , but is usually much smaller. It is exploited by small-scale fishery and aquaculture operations. Description ''Oreochromis leucostictus'' is a relatively deep-bodied tilapia with a fairly small mouth, narrow, rounded head and high back. Juvenile are pale, countershaded and have around 8 thin faint dark bars on the flank beneath the dorsal fin, with other bars on the head and tail. The fins are faintly spotted and there is a rather vague dark 'tilapia mark' at the based on the soft dorsal fin. Adults of both sexes are characterised by white spotting on the flanks and fins. Mature males are very dark, almost black, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nile Tilapia
The Nile tilapia (''Oreochromis niloticus'') is a species of tilapia, a cichlid fish native to the northern half of Africa and the Levante area, including Israel, and Lebanon. Numerous introduced populations exist outside its natural range. It is also commercially known as mango fish, nilotica, or boulti. The first name leads to easy confusion with another tilapia which is traded commercially, the mango tilapia (''Sarotherodon galilaeus''). Description The Nile tilapia reaches up to in length, and can exceed . As typical of tilapia, males reach a larger size and grow faster than females. Wild, natural-type Nile tilapias are brownish or grayish overall, often with indistinct banding on their body, and the tail is vertically striped. When breeding, males become reddish, especially on their fins. Although commonly confused with the blue tilapia (''O. aureus''), that species lacks the striped tail pattern, has a red edge to the dorsal fin (this edge is gray or black in Nile tilap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dodoma
Dodoma ( in Gogo), officially Dodoma City, is the national capital of Tanzania and the capital of the Dodoma Region, with a population of 410,956. In 1974, the Tanzanian government announced that the capital would be moved to Dodoma for social and economic reasons and to centralise the capital within the country. It became the official capital in 1996. Much of the initial design did not come to fruition for a long time. As a result, Dar es Salaam remains the commercial capital of Tanzania and still retains the state house Ikulu, and a large number of government functions. Geography Located in the centre of the country, the town is west of the former capital at Dar es Salaam and south of Arusha, the headquarters of the East African Community. It is north of Iringa through Mtera. It is also west of Morogoro. It covers an area of of which is urbanized. History Originally a small market town known as Idodomya, the modern Dodoma was founded in 1907 by German colonists during ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Sulunga
Lake Sulunga, also known as Bahi Swamp, is a shallow seasonal lake on the border of the Dodoma and Singida regions In Tanzania. It is the largest body of water for both regions during the wet season. It is located about 45 km west of the capital Dodoma Dodoma ( in Gogo), officially Dodoma City, is the national capital of Tanzania and the capital of the Dodoma Region, with a population of 410,956. In 1974, the Tanzanian government announced that the capital would be moved to Dodoma for social a ... in an endorheic basin known as the Bahi depression. It lies at an altitude of and has a maximum extent of . The catchment area is . The lake is about long and wide, but can completely disappear in dry years. Its main tributaries are the Bubu and the Mponde. The lake is surrounded by a variety of settlements and plays an important role in local fishing and animal husbandry. The lake is in danger of being severely affected by mining in the future, as the area is evidently home ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Eyasi
Lake Eyasi (formerly german: Njarasasee, "Njarasa Lake", and ''Hohenlohesee'', "Hohenlohe Lake") is a lake located in Karatu District of Arusha Region in north Tanzania. Lake Eyasi is the largest body of water in Arusha region. It is a seasonal shallow endorheic salt lake on the floor of the Great Rift Valley at the base of the Serengeti Plateau, just south of the Serengeti National Park and immediately southwest of the Ngorongoro Crater in the Crater Highlands of Tanzania. The lake is elongated, orientated southwest to northeast, and lies in the Eyasi- Wembere branch of the Great Rift Valley. The principal inflow is the Sibiti River, which enters the southwestern end. The river may continue to flow somewhat year round, at least in wetter years; the other inflows are all seasonal. The second largest inflow is the Baray, at the northeast. The water carried by the Baray has increased in recent years due to deforestation of the Crater Highlands. The southwest flank of Mount Oldean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkalinity
Alkalinity (from ar, القلوي, al-qaly, lit=ashes of the saltwort) is the capacity of water to resist acidification. It should not be confused with basicity, which is an absolute measurement on the pH scale. Alkalinity is the strength of a buffer solution composed of weak acids and their conjugate bases. It is measured by titrating the solution with an acid such as HCl until its pH changes abruptly, or it reaches a known endpoint where that happens. Alkalinity is expressed in units of concentration, such as meq/L (milliequivalents per liter), μeq/kg (microequivalents per kilogram), or mg/L CaCO3 (milligrams per liter of calcium carbonate). Each of these measurements corresponds to an amount of acid added as a titrant. Although alkalinity is primarily a term used by oceanographers, it is also used by hydrologists to describe temporary hardness. Moreover, measuring alkalinity is important in determining a stream's ability to neutralize acidic pollution from rainfall or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salinity
Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal to ‰). Salinity is an important factor in determining many aspects of the chemistry of natural waters and of biological processes within it, and is a thermodynamic state variable that, along with temperature and pressure, governs physical characteristics like the density and heat capacity of the water. A contour line of constant salinity is called an ''isohaline'', or sometimes ''isohale''. Definitions Salinity in rivers, lakes, and the ocean is conceptually simple, but technically challenging to define and measure precisely. Conceptually the salinity is the quantity of dissolved salt content of the water. Salts are compounds like sodium chloride, magnesium sulfate, potassium nitrate, and sodium bicarbonate which dissolve into ions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphimelas2
''Chereuta'' is a genus of moth Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...s of the family Xyloryctidae. Species * '' Chereuta anthracistis'' Meyrick, 1906 * '' Chereuta chalcistis'' Meyrick, 1906 * '' Chereuta tinthalea'' Meyrick, 1906 References Xyloryctidae Xyloryctidae genera {{Xyloryctidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
