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Fisheries Survey Of Lake Victoria
Lake Victoria supports Africa's largest inland fishery, with the majority of present catch being the invasive Nile perch, introduced to the Lake in the 1950s. Prior to the introduction of Nile perch as well as Nile tilapia, the fish community was very different and consisted mainly of 'Ngege' (''Oreochromis esculentus'') and Victoria tilapia (''O. variabilis'') as well as vast numbers of Haplochromis species. Fish communities in the first half of the 20th century are known primarily from a unique fisheries survey conducted in 1927-1928 by the Colonial Office. In 1927 Michael Graham was sent from the fisheries laboratory in Lowestoft, together with Edgar Barton Worthington to spend a year surveying fisheries in Lake Nyanza ( Lake Victoria).Graham M. (1929.) The Victoria Nyanza and Its Fisheries: A Report on the Fish Survey of Lake Victoria 1927–1928 and Appendices. London: Crown Agents for the Colonies. 256pp. This unique survey represents the first ever systematic characteri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Victoria Fisheries Survey
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger oceans, they do form part of the Earth's water cycle. Lakes are distinct from lagoons, which are generally coastal parts of the ocean. Lakes are typically larger and deeper than ponds, which also lie on land, though there are no official or scientific definitions. Lakes can be contrasted with rivers or streams, which usually flow in a channel on land. Most lakes are fed and drained by rivers and streams. Natural lakes are generally found in mountainous areas, rift zones, and areas with ongoing glaciation. Other lakes are found in endorheic basins or along the courses of mature rivers, where a river channel has widened into a basin. Some parts of the world have many lakes formed by the chaotic drainage patterns left over from the last ic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SS Kavirondo
SS ''Kavirondo'' was a steam tug on Lake Victoria in East Africa. She was named after a local Lake Victoria region and was one of many compact Lake Victoria steamships operated by the Uganda Railway. Bow, McLachlan and Company of Paisley in Renfrewshire, Scotland built her as a "knock down" vessel; that is, she was bolted together in the shipyard at Paisley, all the parts marked with numbers, disassembled into many hundreds of parts and transported in kit form by sea to Mombasa, Kenya. The kit was shipped by railway to Kisumu on the shore of Lake Victoria for reassembly and launch in 1913. In the First World War ''Kavirondo'' was armed as a gunboat. In 1921 she was still recorded as a functioning vessel based in Kisumu - her telegraph address was recorded as 'Kavirontug'. Between 22 August 1927 and 19 February 1928 the SS ''Kavirondo'' was chartered by Michael Graham on behalf of the British Colonial Office in order to conduct the first ever Fisheries Survey of Lake Vict ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplochromis Guiarti
''Haplochromis guiarti'' is a species of cichlid endemic to Lake Victoria though it may now be extinct. This species can reach a length of SL. The specific name honours the French parasitologist Jules Guiart (1870-1965), who was a friend of Jacques Pellegrin Jacques Pellegrin (12 June 1873, Paris – 12 August 1944) was a French zoologist. In Paris, he worked under zoologist Léon Vaillant (chair of reptiles and fishes) at the ''Muséum national d'histoire naturelle''. From 1897, Pellegrin served a ...'s. References guiarti Fish of Tanzania Fish of Lake Victoria Fish described in 1904 Taxonomy articles created by Polbot {{Haplochromis-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schilbe Intermedius
''Schilbe intermedius'' or the silver butter catfish is a widespread species of African catfish. It seems closely related to '' Schilbe uranoscopus'' and these two species are sympatric over part of their ranges. Distribution Widespread in sub-Saharan Africa from the Senegal River across to Somalia and south as far as the Pongola River in South Africa. Biology ''Schilbe intermedius'' is a potamodromous catfish. It is reported to be a pelagic species which occurs mainly in shallow waters and open waters of lakes, it migrates to the surface at night. Generally found in the lower reaches of river systems. It feeds on a fish, either swallowed whole or in pieces and a wide range of invertebrates including terrestrial insects. It is mainly piscivorous once it reaches 13–34 cm in length. ''Schilbe intermedius'' rarely grows to lengths greater than 30 cm. It breeds throughout the year peaking in the rainy season when it migrates into rivers in fairly compact schools to spaw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clarias Gariepinus
''Clarias gariepinus'' or African sharptooth catfish is a species of catfish of the family Clariidae, the airbreathing catfishes. Distribution They are found throughout Africa and the Middle East, and live in freshwater lakes, rivers, and swamps, as well as human-made habitats, such as oxidation ponds or even urban sewage systems. The African sharptooth catfish was introduced all over the world in the early 1980s for aquaculture purposes, so is found in countries far outside its natural habitat, such as Brazil, Vietnam, Indonesia, and India. Description The African sharptooth catfish is a large, eel-like fish, usually of dark gray or black coloration on the back, fading to a white belly. In Africa, this catfish has been reported as being second in size only to the vundu of the Zambesian waters, References External links Reproduction of African catfish [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ripon Barbel
The Ripon barbel (''Labeobarbus altianalis'') is an East African ray-finned fish species in the family Cyprinidae. A notably large barb, its maximum recorded total length is . Taxonomy Like other African "barbs", placement of this species in '' Barbus'' – the genus of the typical barbels and relatives – was provisional. Though called "barbel", it is probably not closely enough related to the typical barbels – the core group of ''Barbus'' – to be considered congeneric. Several supposedly distinct species have been merged into ''B. altianalis'', and numerous subspecies have been proposed. None of these are deemed valid. Some authorities place this species in the genus Labeobarbus. On the other hand, '' B. longifilis'', '' B. paucisquamatus'' and '' B. somereni'' were once considered subspecies of ''L: altianalis'', the second as sspp. ''lobogenysoides'' and ''paucisquamata'' and the third as ssp. ''urundensis''. Significant junior synonyms of ''L. alti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marbled Lungfish
The marbled lungfish (''Protopterus aethiopicus'') is a lungfish of the family Protopteridae. Also known as the leopard lungfish, it is found in Eastern and Central Africa, as well as the Nile region. At 133 billion base pairs, it has the largest known genome of any vertebrate and one of the largest of any organism, along with '' Polychaos dubium'' and '' Paris japonica'' at 670 billion and 150 billion, respectively. The marbled lungfish is caught in large numbers throughout much of its range, including several hundred metric tonnes per year in the Mwanza Gulf of Lake Victoria alone. It is mostly a food fish, although this varies depending on the exact community, with some recognizing it as a delicacy and others strongly disliking its taste or considering it as a taboo to eat it. In some regions, parts of this fish are used as traditional medicine. Description The marbled lungfish is smooth, elongated, and cylindrical with deeply embedded scales. The tail is very long and has t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Singida Tilapia
''Oreochromis esculentus'', the Singida tilapia or Graham's tilapia, is a species of cichlid endemic to the Lake Victoria basin, including some of its satellite lakes such as Kyoga, in Tanzania, Uganda, and Kenya. Its common name refers to Lake Singida, but this population is the result of an introduction that happened in the 1950s. This fish is highly valued by local fishermen, who know it as ''ngege''. In 1927-1928 Michael Graham conducted the first ever systematic Fisheries Survey of Lake Victoria. In his official report of the expedition, Graham wrote that "The ngege or satu ''Tilapia esculenta'', is the most important food fish of the lake, whether for native or non-native consumption. No other fish equals it in the quality of the flesh. It is convenient size for trade, travels well and is found in much greater numbers than other important fish, such as semutundu (Luganda), ''Bagrus sp.'.Graham M. (1929.) The Victoria Nyanza and Its Fisheries: A Report on the Fish Surv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conservation Biology (journal)
''Conservation Biology'' is a bimonthly peer-reviewed scientific journal of the Society for Conservation Biology, published by Wiley-Blackwell and established in May 1987. It covers the science and practice of conserving Earth's biological diversity, including issues concerning any of the Earth's ecosystems or regions. The editor-in-chief is Mark Burgman. Scope The scientific papers in the journal cover a variety of topics, such as population ecology and genetics, climate change, freshwater and marine conservation, ecosystem management, citizen science, and other human dimensions of conservation, but all topics focus primarily on conservation relevance rather than specific ecosystems, species, or situations. Subscription to the journal is only open to members of Society for Conservation Biology. Journal Metrics According to the ''Journal Citation Reports'', the journal has a 2019 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytoplankton
Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater ecosystems. The name comes from the Greek words (), meaning 'plant', and (), meaning 'wanderer' or 'drifter'. Phytoplankton obtain their energy through photosynthesis, as do trees and other plants on land. This means phytoplankton must have light from the sun, so they live in the well-lit surface layers ( euphotic zone) of oceans and lakes. In comparison with terrestrial plants, phytoplankton are distributed over a larger surface area, are exposed to less seasonal variation and have markedly faster turnover rates than trees (days versus decades). As a result, phytoplankton respond rapidly on a global scale to climate variations. Phytoplankton form the base of marine and freshwater food webs and are key players in the global carbon cycle. They account for about half of global photosynthetic activity and at least half of the oxygen production, desp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zooplankton
Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by currents in the ocean, or by currents in seas, lakes or rivers. Zooplankton can be contrasted with phytoplankton, which are the plant component of the plankton community ("phyto" comes from the Greek word for ''plant''). Zooplankton are heterotrophic (other-feeding), whereas phytoplankton are autotrophic (self-feeding). This means zooplankton cannot manufacture their own food but must eat other plants or animals instead — in particular they eat phytoplankton. Zooplankton are generally larger than phytoplankton, most are microscopic, but some (such as jellyfish) are macroscopic and can be seen with the naked eye. Many protozoans (single-celled protists that prey on other microscopic life) are zooplankton, including zooflagellates, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
