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Stone Sucker
''Garra ceylonensis'' (the stone sucker or Ceylon logsucker) is a species of ray-finned fish in the cyprinid family. It is endemic to rivers and streams in Sri Lanka (formerly known as "Ceylon") - and is considered as a schooling fish. It is a rheophilic species and occurs in slow to moderately flowing rivers and streams, and ascends small, rocky streams in order to breed. It primarily feeds on algae such as diatoms. Taxonomy A 2021 study found ''G. ceylonensis'' to be a sister species to the mullya garra (''Garra mullya'') from mainland India, which itself may comprise two species. ''G. ceylonensis'' comprises primarily six genetically distinct subclades that are each tied to a single river basin, albeit with two exceptions. Evolution The ancestor of ''G. ceylonensis'' colonized Sri Lanka from India once during the late Pliocene, via a former isthmus that existed in the Palk Strait, and from the Pleistocene until its submergence, the still-exposed isthmus may have had a h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pieter Bleeker
Pieter Bleeker (10 July 1819 – 24 January 1878) was a Dutch medical doctor, ichthyologist, and herpetologist. He was famous for the ''Atlas Ichthyologique des Indes Orientales Néêrlandaises'', his monumental work on the fishes of East Asia published between 1862 and 1877. Life and work Bleeker was born on 10 July 1819 in Zaandam. He was employed as a medical officer in the Royal Netherlands East Indies Army from 1842 to 1860, (in French). stationed in the Dutch East Indies (now Indonesia). During that time, he did most of his ichthyology work, besides his duties in the army. He acquired many of his specimens from local fishermen, but he also built up an extended network of contacts who would send him specimens from various government outposts throughout the islands. During his time in Indonesia, he collected well over 12,000 specimens, many of which currently reside at the Naturalis Biodiversity Center in Leiden. Bleeker corresponded with Auguste Duméril of Paris. His wor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek grc, label=none, πλεῖστος, pleīstos, most and grc, label=none, καινός, kainós (latinized as ), 'new'. At the end of the preceding Pliocene, the previously isolated North and South American continents were joined by the Isthmus of Panama, causing Great American Interchang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freshwater Fish Of Sri Lanka
Sri Lanka is a tropical island situated close to the southern tip of India. It is situated in the middle of Indian Ocean. Because of being an island, Sri Lanka has many endemic freshwater fauna, including fish, crabs, molluscs, and other aquatic insects. Species List Class: Actinopterygii Freshwater fish are physiologically differ from marine and brackish water forms. The low salinity and high osmotic pressure makes them so different. Few fish can be found in all three ecological systems. There are 95 species of freshwater fish occur in the country, where 53 of those are endemic. 41% of all known species of fish of Sri Lanka are found in freshwater. There are about 70% of endemism of those fish. Most of them are listed into IUCN categories. Four ''Devario'' species were described in 2017 by Batuwita et al. However, the taxonomy and descriptions were cited as problematic by fellow local ichthyologists. Note: introduced species are not included in the list. Go to '' List of intro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Garra
''Garra'' is a genus of fish in the family Cyprinidae. These fish are one example of the "log suckers", sucker-mouthed barbs and other cyprinids commonly kept in aquaria to keep down algae. The doctor fish of Anatolia and the Middle East belongs in this genus. The majority of the more than 140 species of garras are native to Asia, but about one-fifth of the species are from Africa (East, Middle and West, but by far the highest species richness in Ethiopia). The genus was established by Francis Buchanan-Hamilton in 1822 as a subgenus of ''Cyprinus'' (which at that time was a " wastebin, basket genus" for carp-like cyprinids); though it didn't lead to an act of him to designate a type species by the time. However, as no other garras except the newly discovered '' G. lamta'' were known to science in 1822, this was designated as the type species by Pieter Bleeker in 1863. The garras and their closest relatives are sometimes placed in a subfamily Garrinae, but this seems hardly wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydropower
Hydropower (from el, ὕδωρ, "water"), also known as water power, is the use of falling or fast-running water to Electricity generation, produce electricity or to power machines. This is achieved by energy transformation, converting the Potential energy, gravitational potential or kinetic energy of a water source to produce power. Hydropower is a method of sustainable energy production. Hydropower is now used principally for Hydroelectricity, hydroelectric power generation, and is also applied as one half of an energy storage system known as pumped-storage hydroelectricity. Hydropower is an attractive alternative to fossil fuels as it does not directly produce Carbon dioxide in Earth's atmosphere, carbon dioxide or other Air pollution, atmospheric pollutants and it provides a relatively consistent source of power. Nonetheless, it has economic, sociological, and environmental downsides and requires a sufficiently energetic source of water, such as a river or elevated lake. Int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deforestation
Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated deforestation occurs in tropical rainforests. About 31% of Earth's land surface is covered by forests at present. This is one-third less than the forest cover before the expansion of agriculture, a half of that loss occurring in the last century. Between 15 million to 18 million hectares of forest, an area the size of Bangladesh, are destroyed every year. On average 2,400 trees are cut down each minute. The Food and Agriculture Organization of the United Nations defines deforestation as the conversion of forest to other land uses (regardless of whether it is human-induced). "Deforestation" and "forest area net change" are not the same: the latter is the sum of all forest losses (deforestation) and all forest gains (forest expansion) in a gi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fishkeeping
Fishkeeping is a popular hobby, practiced by aquarists, concerned with keeping fish in a home aquarium or garden pond. There is also a piscicultural fishkeeping industry, serving as a branch of agriculture. Origins of fishkeeping Fish have been raised as food in pools and ponds for thousands of years. Brightly colored or tame specimens of fish in these pools have sometimes been valued as pets rather than food. Many cultures, ancient and modern, have kept fish for both functional and decorative purposes. Ancient Sumerians kept wild-caught fish in ponds, before preparing them for meals. Depictions of the sacred fish of Oxyrhynchus kept in captivity in rectangular temple pools have been found in ancient Egyptian art. Similarly, Asia has experienced a long history of stocking rice paddies with freshwater fish suitable for eating, including various types of catfish and cyprinid. Selective breeding of carp into today's popular and completely domesticated koi and fancy goldfish b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biological species. It uses a set of precise criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world. With its strong scientific base, the IUCN Red List is recognized as the most authoritative guide to the status of biological diversity. A series of Regional Red Lists are produced by countries or organizations, which assess the risk of extinction to species within a political management unit. The aim of the IUCN Red List is to convey the urgency of conservation issues to the public and policy makers, as well as help the international community to reduce species extinction. According to IUCN the formally stated goals of the Red List are to provi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Near-threatened Species
A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be vulnerable to endangerment in the near future, but it does not currently qualify for the threatened status. The IUCN notes the importance of re-evaluating near-threatened taxon at appropriate intervals. The rationale used for near-threatened taxa usually includes the criteria of vulnerable which are plausible or nearly met, such as reduction in numbers or range. Near-threatened species evaluated from 2001 onwards may also be ones which are dependent on conservation efforts to prevent their becoming threatened, whereas before this conservation-dependent species were given a separate category ("Conservation Dependent"). Additionally, the 402 conservation-dependent taxa may also be considered near-threatened. IUCN Categories and Criteria version 2.3 Before 2001, the IUCN used the version 2.3 Categories and Criteri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stream Capture
Stream capture, river capture, river piracy or stream piracy is a geomorphological phenomenon occurring when a stream or river drainage system or watershed is diverted from its own bed, and flows instead down the bed of a neighbouring stream. This can happen for several reasons, including: *Tectonic earth movements, where the slope of the land changes, and the stream is tipped out of its former course *Natural damming, such as by a landslide or ice sheet *Erosion, either **Headward erosion of one stream valley upwards into another, or **Lateral erosion of a meander through the higher ground dividing the adjacent streams. **Within an area of karst topography, where streams may ''sink'', or flow underground (a sinking or losing stream) and then reappear in a nearby stream valley *Glacier retreat The additional water flowing down the capturing stream may accelerate erosion and encourage the development of a canyon (gorge). The now-dry valley of the original stream is known as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relict (biology)
In biogeography and paleontology, a relict is a population or taxon of organisms that was more widespread or more diverse in the past. A relictual population is a population currently inhabiting a restricted area whose range was far wider during a previous geologic epoch. Similarly, a relictual taxon is a taxon (e.g. species or other lineage) which is the sole surviving representative of a formerly diverse group. Definition A relict (or relic) plant or animal is a taxon that persists as a remnant of what was once a diverse and widespread population. Relictualism occurs when a widespread habitat or range changes and a small area becomes cut off from the whole. A subset of the population is then confined to the available hospitable area, and survives there while the broader population either shrinks or evolves divergently. This phenomenon differs from endemism in that the range of the population was not always restricted to the local region. In other words, the species or group did n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Local Extinction
Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinctions. Local extinctions mark a change in the ecology of an area. In recent times, local extinction has sometimes been followed by a replacement of the species taken from other locations; wolf reintroduction is an example of this. The term "local extinction" is highly vernacular. The more proper biological term is ''extirpation''. Discussion Glaciation can lead to local extinction. This was the case during the Pleistocene glaciation event in North America. During this period, most of the native North American species of earthworm were killed in places covered by glaciation. This left them open for colonization by European earthworms brought over in soil from Europe. Species naturally become extirpated from islands over time. The number ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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