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Haplochromis Vonlinnei
''Haplochromis vonlinnei'' is a species of cichlid endemic to Lake Victoria. It is greyish in color with a distinct mid-lateral band, and a rather slender shape. It feeds mainly on smaller fish. This species can reach a length of SL. The population of the species has declined due to the introduction of the Nile perch in the 1950s. It has not been recorded since 1980 and the IUCN lists it as " Critically Endangered" and considers it may already be extinct. This fish is named in honour of the Swedish naturalist, Carl Linnaeus. Description ''Haplochromis vonlinnei'' is a moderate-sized, slender cichlid with an acute snout, slightly protruding lower jaw and curved teeth. It is a greyish color with a narrow, intermittent blackish dorsal-lateral band and a broader, more distinct mid-lateral band. The flanks are yellowish and the belly white. In the male, the anal fin is grey with two to four bright orange circular spots with thin white rims (egg dummies). In the female, the anal fin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martien Van Oijen
Martien is both a given name and a surname. Notable people with the name include: *Martien Houtkooper (1891–1961), Dutch footballer *Martien Kas (born 1966), Dutch neuroscientist *Martien Vreijsen (born 1955), Dutch footballer *Samuel W. Martien Samuel Winter Martien (November 12, 1854 – May 31, 1946) was a wealthy cotton planter who served as a Democrat from 1906 to 1920 in the Louisiana House of Representatives from his adopted Tensas Parish in northeastern Louisiana. At the ... (1854–1946), American cotton planter and politician {{given name, type=both Dutch masculine given names ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplochromis
''Haplochromis'' is a ray-finned fish genus in the family Cichlidae. It has been used as the default "wastebin taxon" for Pseudocrenilabrinae cichlids of the East African Rift, and as such became the "largest" fish "genus". Many of these cichlids are popular aquarium fishes; like similar Haplochromini they are known as "haplos", "happies" or "haps" among aquarium enthusiasts. The genus was established by F.M. Hilgendorf in 1888. It was originally conceived as a subgenus of A.C.L.G. Günther's ''"Chromis"'', at that time an even larger "wastebin genus" for Pseudocrenilabrinae cichlids. The type species of Hilgendorf was '' H. obliquidens''. ''"Chromis"'' of Günther turned out to be a junior homonym of G. Cuvier's ocean fish genus '' Chromis'', already established in 1814, and was abolished. As the years went by, other genera of (mostly) Haplochromini were lumped with and split again from ''Haplochromis'', and the final delimitation of the clade around ''H. obliquidens'' is not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Of Lake Victoria
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts. The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods. Mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinction
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dodos, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trawling
Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net used for trawling is called a trawl. This principle requires netting bags which are towed through water to catch different species of fishes or sometimes targeted species. Trawls are often called towed gear or dragged gear. The boats that are used for trawling are called trawlers or draggers. Trawlers vary in size from small open boats with as little as 30 hp (22 kW) engines to large factory trawlers with over 10,000 hp (7.5 MW). Trawling can be carried out by one trawler or by two trawlers fishing cooperatively (pair trawling). Trawling can be contrasted with trolling. While trawling involves a net and is typically done for commercial usage, trolling instead involves a reed, rod and a bait or a lure and is typically done for recreational purposes. Trawling is also commonly used as a scientific sampling, or survey, method. Bottom vs. midwater trawling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Predation
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the host) and parasitoidism (which always does, eventually). It is distinct from scavenging on dead prey, though many predators also scavenge; it overlaps with herbivory, as seed predators and destructive frugivores are predators. Predators may actively search for or pursue prey or wait for it, often concealed. When prey is detected, the predator assesses whether to attack it. This may involve ambush or pursuit predation, sometimes after stalking the prey. If the attack is successful, the predator kills the prey, removes any inedible parts like the shell or spines, and eats it. Predators are adapted and often highly specialized for hunting, with acute senses such as vision, hearing, or smell. Many predatory animals, both vertebrate and inv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demersal
The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of the larger profundal zone. Being just above the ocean floor, the demersal zone is variable in depth and can be part of the photic zone where light can penetrate, and photosynthetic organisms grow, or the aphotic zone, which begins between depths of roughly and extends to the ocean depths, where no light penetrates. Fish The distinction between demersal species of fish and pelagic species is not always clear cut. The Atlantic cod (''Gadus morhua'') is a typical demersal fish, but can also be found in the open water column, and the Atlantic herring (''Clupea harengus'') is predominantly a pelagic species but forms large aggregations near the seabed when it spawns on banks of gravel. Two types of fish inhabit the demersal zone: those ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mwanza Gulf
Mwanza City, also known as Rock City to the residents, is a port city and capital of Mwanza Region on the southern shore of Lake Victoria in north-western Tanzania. With an urban population of 1,182,000 in 2021, it is Tanzania's second largest city, after Dar es Salaam. It is also the second largest city in the Lake Victoria basin after Kampala, Uganda and ahead of Kisumu, Kenya at least in population size. Within the East African community, Mwanza city is the fifth largest city after Dar, Nairobi, Mombasa, and Kampala. It is slightly ahead of Kigali, Kisumu, and Bujumbura in the population of city proper limits. However, in terms of infrastructure, Kigali and Kisumu cities are way ahead of Mwanza. Mwanza city is also the capital city of Mwanza Region, and is administratively divided into two municipal districts within that Region - Ilemela and Nyamagana. Ethnicity The Sukuma constitute over 90 percent of the population of the Mwanza Region. Other ethnic groups in the region, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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