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Oreochromis Variabilis
''Oreochromis variabilis'', the Victoria tilapia, is a species of African cichlid native to Lake Victoria and its tributaries, Lake Kyoga, Lake Kwania, and Lake Bisina (Salisbury), as well as being found in the Victoria Nile above Murchison Falls. This species can reach a standard length of . This species is important to local commercial fisheries and is potentially important in aquaculture. It is also found in the aquarium trade. Despite its common name, it is not the only tilapia native to Lake Victoria. The equally threatened '' O. esculentus'' has a similar distribution. Description ''Oreochromis variabilis'' has typical characteristics of a cichlid fish: long dorsal fin with both spiny and soft rays, a broken lateral line, a single pair of nostrils and a single lower pharyngeal bone. Like other typical 'tilapias', it has relatively small closely packed teeth, numerous gill rakers and juveniles have a dark 'tilapia spot' at the base of the soft-rayed part of the dorsal f ...
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George Albert Boulenger
George Albert Boulenger (19 October 1858 – 23 November 1937) was a Belgian-British zoologist who described and gave scientific names to over 2,000 new animal species, chiefly fish, reptiles, and amphibians. Boulenger was also an active botanist during the last 30 years of his life, especially in the study of roses. Life Boulenger was born in Brussels, Belgium, the only son of Gustave Boulenger, a Belgian public notary, and Juliette Piérart, from Valenciennes. He graduated in 1876 from the Free University of Brussels with a degree in natural sciences, and worked for a while at the Royal Belgian Institute of Natural Sciences, Brussels, as an assistant naturalist studying amphibians, reptiles, and fishes. He also made frequent visits during this time to the ''Muséum national d'Histoire naturelle'' in Paris and the British Museum in London. In 1880, he was invited to work at the Natural History Museum, then a department of the British Museum, by Dr. Albert C. L. G. Günther a ...
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Lake Tanganyika
Lake Tanganyika () is an African Great Lake. It is the second-oldest freshwater lake in the world, the second-largest by volume, and the second-deepest, in all 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 (DRC), Burundi, and Zambia, with Tanzania (46%) and DRC (40%) possessing the majority of the lake. It drains into the Congo River system and ultimately into the Atlantic Ocean. Etymology "Tanganika" was the name of the lake that Henry Morton Stanley encountered when he was at Ujiji in 1876. The name first originated from the Bembe language when they arrived in South Kivu around the 7th century, they discovered the lake and started calling it “êtanga ‘ya’ni’â” which means “a big river” in their Bantu language. Stanley found also other names for the lake among different ethnic groups, like the Kimana, the Yemba and the Msaga. An alt ...
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Nile Perch
The Nile perch (''Lates niloticus''), also known as the African snook, Goliath perch, African barramundi , Goliath barramundi, Giant lates or the Victoria perch, is a species of freshwater fish in family Latidae of order Perciformes. It is widespread throughout much of the Afrotropical realm, being native to the Congo, Nile, Senegal, Niger and Lake Chad, Volta, Lake Turkana, and other river basins. It also occurs in the brackish waters of Lake Maryut in Egypt. The Nile perch is a fish of substantial economic and food-security importance in East Africa. Originally described as ''Labrus niloticus,'' among the marine wrasses, the species has also been referred to as ''Centropomus niloticus''. Common names include African snook, Victoria perch (a misleading trade name, as the species is not native to Lake Victoria, though they have been introduced there), and many local names in various African languages, such as the Luo name ''mbuta'' or ''mputa''. In Tanzania, it is called '' ...
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Plankton
Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish and whales. Marine plankton include bacteria, archaea, algae, protozoa and drifting or floating animals that inhabit the saltwater of oceans and the brackish waters of estuaries. Freshwater plankton are similar to marine plankton, but are found in the freshwaters of lakes and rivers. Plankton are usually thought of as inhabiting water, but there are also airborne versions, the aeroplankton, that live part of their lives drifting in the atmosphere. These include plant spores, pollen and wind-scattered seeds, as well as microorganisms swept into the air from terrestrial dust storms and oceanic plankton swept into the air ...
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Oreochromis Variabilis
''Oreochromis variabilis'', the Victoria tilapia, is a species of African cichlid native to Lake Victoria and its tributaries, Lake Kyoga, Lake Kwania, and Lake Bisina (Salisbury), as well as being found in the Victoria Nile above Murchison Falls. This species can reach a standard length of . This species is important to local commercial fisheries and is potentially important in aquaculture. It is also found in the aquarium trade. Despite its common name, it is not the only tilapia native to Lake Victoria. The equally threatened '' O. esculentus'' has a similar distribution. Description ''Oreochromis variabilis'' has typical characteristics of a cichlid fish: long dorsal fin with both spiny and soft rays, a broken lateral line, a single pair of nostrils and a single lower pharyngeal bone. Like other typical 'tilapias', it has relatively small closely packed teeth, numerous gill rakers and juveniles have a dark 'tilapia spot' at the base of the soft-rayed part of the dorsal f ...
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Mouthbrooder
Mouthbrooding, also known as oral incubation and buccal incubation, is the care given by some groups of animals to their offspring by holding them in the mouth of the parent for extended periods of time. Although mouthbrooding is performed by a variety of different animals, such as the Darwin's frog, fish are by far the most diverse mouthbrooders. Mouthbrooding has evolved independently in several different families of fish. Mouthbrooding behaviour Paternal mouthbrooders are species where the male looks after the eggs. Paternal mouthbrooders include the arowana, various mouthbrooding bettas and gouramies such as ''Betta pugnax'', and sea catfish such as ''Ariopsis felis''. Among cichlids, paternal mouthbrooding is relatively rare, but is found among some of the tilapiines, most notably the black-chin tilapia ''Sarotherodon melanotheron''. In the case of the maternal mouthbrooders, the female takes the eggs. Maternal mouthbrooders are found among both African and South American ci ...
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Lake Malawi
Lake Malawi, also known as Lake Nyasa in Tanzania and Lago Niassa in Mozambique, is an African Great Lake and the southernmost lake in the East African Rift system, located between Malawi, Mozambique and Tanzania. It is the fifth largest fresh water lake in the world by volume, the ninth largest lake in the world by area—and the third largest and second deepest lake in Africa. Lake Malawi is home to more species of fish than any other lake in the world, including at least 700 species of cichlids.Turner, Seehausen, Knight, Allender, and Robinson (2001). "How many species of cichlid fishes are there in African lakes?" ''Molecular Ecology'' 10: 793–806. The Mozambique portion of the lake was officially declared a reserve by the Government of Mozambique on June 10, 2011,WWF (10 June 2011)"Mozambique’s Lake Niassa declared reserve and Ramsar site"Retrieved 17 July 2014. while in Malawi a portion of the lake is included in Lake Malawi National Park. Lake Malawi is a meromic ...
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Mbuna
Mbuna (pronounced Mmm-boo - nah ) is the common name for a large group of African cichlids from Lake Malawi, and are members of the haplochromine family. The name ''mbuna'' means "rockfish" in the language of the Tonga people of Malawi.Loiselle Paul V. (1988) ''A Fishkeepers Guide to African Cichlids.'' p 97. Salamander Books, London & New York, . As the name implies, most mbuna are cichlids that live among the piles of rocks and along the rocky shores of Lake Malawi, as opposed to the utaka, cichlids that live in the open water or on sandy shores or soft substrates. Some species of mbuna are highly sexually dimorphic, although many are not. Among biologists, almost all of the cichlid species of Lake Malawi, including mbuna and non mbuna such as the utaka, are believed to have descended from one or a very few species that became isolated in the lake. With rising water levels, new habitats could be colonized and the many isolated rocky outcrops allowed new mbuna species to form.G ...
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Haplochromine
__NOTOC__ The haplochromine cichlids are a tribe of cichlids in subfamily Pseudocrenilabrinae called Haplochromini. This group includes the type genus (''Haplochromis'') plus a number of closely related genera such as '' Aulonocara'', '' Astatotilapia'', and '' Chilotilapia''. They are endemic to eastern, southern and northern Africa, except for ''Astatotilapia flaviijosephi'' in the ''Middle East''. A common name in a scientific context is East African cichlids – while they are not restricted to that region, they are the dominant Cichlidae there. This tribe was extensively studied by Ethelwynn Trewavas, who made major reviews in 1935 and 1989, at the beginning and at the end of her career in ichthyology. Even today, numerous new species are being described each year. The haplochromines were in older times treated as subfamily Haplochrominae, However, the great African radiation of pseudocrenilabrine cichlids is certainly not monophyletic without them, and thus they are t ...
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Melanin
Melanin (; from el, μέλας, melas, black, dark) is a broad term for a group of natural pigments found in most organisms. Eumelanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino acid tyrosine is followed by polymerization. The melanin pigments are produced in a specialized group of cells known as melanocytes. Functionally, eumelanin serves as protection against Ultraviolet, UV radiation. There are five basic types of melanin: eumelanin, pheomelanin, neuromelanin, allomelanin and pyomelanin. The most common type is eumelanin, of which there are two types— brown eumelanin and black eumelanin. Pheomelanin, which is produced when melanocytes are malfunctioning due to derivation of the gene to its recessive format is a cysteine-derivative that contains polybenzothiazine portions that are largely responsible for the of red yellow tint given to some skin or hair colors. Neuromelanin is found in the brain. Research ha ...
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Polymorphism (biology)
In biology, polymorphism is the occurrence of two or more clearly different morphs or forms, also referred to as alternative ''phenotypes'', in the population of a species. To be classified as such, morphs must occupy the same habitat at the same time and belong to a panmictic population (one with random mating). Ford E.B. 1965. ''Genetic polymorphism''. Faber & Faber, London. Put simply, polymorphism is when there are two or more possibilities of a trait on a gene. For example, there is more than one possible trait in terms of a jaguar's skin colouring; they can be light morph or dark morph. Due to having more than one possible variation for this gene, it is termed 'polymorphism'. However, if the jaguar has only one possible trait for that gene, it would be termed "monomorphic". For example, if there was only one possible skin colour that a jaguar could have, it would be termed monomorphic. The term polyphenism can be used to clarify that the different forms arise from the s ...
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