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Haplochromis Pyrrhocephalus
''Haplochromis pyrrhocephalus'' is a species of cichlid fish endemic to Lake Victoria in East Africa. This species can reach a standard length of . Historically a common species, the species rapidly declined and went unrecorded from the mid-1980s to the early 1990s when it reappeared. As in several other Lake Victoria haplochromines of demersal habitats, its sudden decline has been attributed to the introduced Nile perch and eutrophication of the lake's water. After its reappearance it has again become common, likely aided by adaptions to the changes in its habitat. This includes it moving into shallower water (it used to be found mostly at depths of ), feeding on insects larvae and similar animals (it used to feed on zooplankton), getting a larger caudal peduncle compared to the head (allowing it to swim faster to escape the Nile perch), and larger gills (allowing it to cope with lower oxygen-levels). The ability to make these changes possibly is related to a level of hybridizat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frans Witte
Frans is an Afrikaans, Danish, Dutch, Finnish, Icelandic, Norwegian, and Swedish given name, sometimes as a short form of ''François''. One cognate of Frans in English is ''Francis''. Given name * Frans van Aarssens (1572–1641), Dutch diplomat and statesman * Frans Ackerman (1330–1387), Flemish statesman * Frans Adelaar (born 1960), Dutch football player and manager * Frans Alphons Maria Alting von Geusau (born 1933), Dutch legal scholar and diplomat * Frans Aerenhouts (born 1937), Belgian cyclist * Frans Ananias (born 1972), Namibian footballer * Frans Andersson (1911–1988), Danish bass-baritone * Frans Andriessen (1929–2019), Dutch politician * Frans Anneessens (1660–1719), Flemish protest leader * Frans van Anraat (born 1942), Dutch businessman and convicted war criminal * Frans Badens ( fl. 1571–1618), Flemish painter * Frans Bak (born 1958), Danish composer, choral conductor, saxophonist, and pianist * Frans Decker (1684–1751), 18th-century painter from the Nor ... [...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, fo ... [...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] |
Fish Of Tanzania
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. Most ... [...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] |
Haplochromis Laparogramma
''Haplochromis laparogramma'' is a species of cichlid endemic to 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 tropical lake, and the world's second-largest fresh water lake by surface area after .... This species can reach a length of SL. References laparogramma Fish of Lake Victoria Fish of Tanzania Fish described in 1969 Taxonomy articles created by Polbot {{Haplochromis-stub ... [...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] |
Fish Gill
Fish gills are organs that allow fish to breathe underwater. Most fish exchange gases like oxygen and carbon dioxide using gills that are protected under gill covers (operculum) on both sides of the pharynx (throat). Gills are tissues that are like short threads, protein structures called filaments. These filaments have many functions including the transfer of ions and water, as well as the exchange of oxygen, carbon dioxide, acids and ammonia. Each filament contains a capillary network that provides a large surface area for exchanging oxygen and carbon dioxide. Fish exchange gases by pulling oxygen-rich water through their mouths and pumping it over their gills. Within the gill filaments, capillary blood flows in the opposite direction to the water, causing counter-current exchange. The gills push the oxygen-poor water out through openings in the sides of the pharynx. Some fish, like sharks and lampreys, possess multiple gill openings. However, bony fish have a single gill op ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caudal Peduncle
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with the spine and are supported only by muscles. Their principal function is to help the fish swim. Fins located in different places on the fish serve different purposes such as moving forward, turning, keeping an upright position or stopping. Most fish use fins when swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling. Fins can also be used for other purposes; male sharks and mosquitofish use a modified fin to deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines in their dorsal fins that inject venom, anglerfish use the first spine of their dorsal fin like a fishing rod to lu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eutrophication
Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytoplankton productivity". Water bodies with very low nutrient levels are termed oligotrophic and those with moderate nutrient levels are termed mesotrophic. Advanced eutrophication may also be referred to as dystrophic and hypertrophic conditions. Eutrophication can affect freshwater or salt water systems. In freshwater ecosystems it is almost always caused by excess phosphorus. In coastal waters on the other hand, the main contributing nutrient is more likely to be nitrogen, or nitrogen and phosphorus together. This depends on the location and other factors. When occurring naturally, eutrophication is a very slow process in which nutrients, especially phosphorus compounds and organic matter, accumulate in water bodies. These nutrients deriv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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