The spotted danio or dwarf danio is a tropical fish belonging to the minnow family. Originating in northern Myanmar, this fish is sometimes found in community tanks by fish-keeping hobbyists, it grows to a maximum length of 1.5 inches. In the wild, the spotted danio is found in rivers in a tropical climate and prefers water with a pH of 6.5 – 7.0 and a hardness of 5.0 – 12.0 dGH, an ideal temperature range of 75–82 °F. The spotted danio is oviparous. Froese and Pauly, eds.. "Danio nigrofasciatus" in FishBase. April 2004 version. Danio nigrofasciatus
An aquarium is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, amphibians, aquatic reptiles such as turtles, aquatic plants; the term "aquarium", coined by English naturalist Philip Henry Gosse, combines the Latin root aqua, meaning water, with the suffix -arium, meaning "a place for relating to". The aquarium principle was developed in 1850 by the chemist Robert Warington, who explained that plants added to water in a container would give off enough oxygen to support animals, so long as the numbers of animals did not grow too large; the aquarium craze was launched in early Victorian England by Gosse, who created and stocked the first public aquarium at the London Zoo in 1853, published the first manual, The Aquarium: An Unveiling of the Wonders of the Deep Sea in 1854. An aquarium is a water-filled tank. Small aquariums are kept in the home by hobbyists. There are larger public aquariums in many cities.
This kind of aquarium is other aquatic animals in large tanks. A large aquarium may have otters, turtles and other sea animals. Most aquarium tanks have plants. An aquarist owns fish or maintains an aquarium constructed of glass or high-strength acrylic. Cuboid aquaria are known as fish tanks or tanks, while bowl-shaped aquaria are known as fish bowls. Size can range from a small glass bowl, under a gallon in volume, to immense public aquaria of several thousand gallons. Specialized equipment maintains appropriate water quality and other characteristics suitable for the aquarium's residents. In 1369, the Hongwu Emperor of China established a porcelain company that produced large porcelain tubs for maintaining goldfish. Leonhard Baldner, who wrote Vogel-, Fisch- und Tierbuch in 1666, maintained weather loaches and newts, it is sometimes held that the aquarium was invented by the Romans, who are said to have kept sea barbels in marble-and-glass tanks, but this is unlikely to be true. In 1832, Jeanne Villepreux-Power, a pioneering French marine biologist, became the first person to create aquaria for experimenting with aquatic organisms.
In 1836, soon after his invention of the Wardian case, Dr. Nathaniel Bagshaw Ward proposed to use his tanks for tropical animals. In 1841 he did so, though only with toy fish. However, he soon housed real animals. In 1838, Félix Dujardin noted owning a saltwater aquarium. In 1846, Anne Thynne maintained stony corals and seaweed for three years, was credited as the creator of the first balanced marine aquarium in London. English chemist Robert Warington experimented with a 13-gallon container, which contained goldfish and snails, creating one of the first stable aquaria; the aquarium principle was developed by Warington, explaining that plants added to water in a container would give off enough oxygen to support animals, so long as their numbers do not grow too large. He published his findings in 1850 in the Chemical Society's journal; the keeping of fish in an aquarium spread quickly. In the United Kingdom, it became popular after ornate aquaria in cast-iron frames were featured at the Great Exhibition of 1851.
In 1853, the aquarium craze was launched in England by Philip Henry Gosse who created and stocked the first public aquarium in the London Zoo which came to be known as the Fish House. Gosse coined the word "aquarium", opting for this term in 1854 in his book The Aquarium: An Unveiling of the Wonders of the Deep Sea. In this book, Gosse discussed saltwater aquaria. In the 1850s, the aquarium became a fad in the United Kingdom. Tank designs and techniques for maintaining water quality were developed by Warington cooperating with Gosse until his critical review of the tank water composition. Edward Edwards developed these glass-fronted aquaria in his 1858 patent for a "dark-water-chamber slope-back tank", with water circulating to a reservoir beneath. Germans soon rivaled the British in their interest. In 1854, an anonymous author had two articles published about the saltwater aquaria of the United Kingdom: Die Gartenlaube entitled Der Ocean auf dem Tische. However, in 1856, Der See im Glase was published, discussing freshwater aquaria, which were much easier to maintain in landlocked areas.
In 1862 William Alford Lloyd bankrupt because of the craze in England being over, moved to Grindel Dammthor, Hamburg, to supervise the installation of the circulating system and tanks at the Hamburg Aquarium. During the 1870s, some of the first aquarist societies were appearing in Germany; the United States soon followed. Published in 1858, Henry D. Butler's The Family Aquarium was one of the first books written in the United States about the aquarium. According to the July issue of The North American Review of the same year, William Stimson may have owned some of the first functional aquaria, had as many as seven or eight; the first aquarist society in the United States was founded in New York City in 1893, followed by others. The New York Aquarium Journal, first published in October 1876, is considered to be the world's first aquarium magazine. In the Victorian era in the United Kingdom, a common design for the home aquarium was a glass front with the other sides made of wood; the bottom would be heated from below.
More advanced systems soon began to be introduced, along with tanks of
Danio margaritatus, the celestial pearl danio referred to in the aquarium trade as galaxy rasbora or Microrasbora sp.'Galaxy', is a small cyprinid from Myanmar. It has so far been found only in a small area near Hopong east of Inle Lake, at an altitude of over 1,000 m, its habitat is part of namely the Nam Lang and Nam Pawn Rivers. Discovered in 2006, the species appeared in the aquarium trade, where its small size and bright colours made it an instant hit; this is a small, plump danionin with a markedly blunt snout, measuring just 2–2.5 cm standard length. The body is about three times as long. In general shape, it resembles Danio erythromicron more than any other known species; this species shows some sexual dimorphism: males have a bright-blue background color, their fins are more brightly colored. The tail end of their bodies is higher than in females; the body is sprinkled with pearly dots. The back is bronzy green, the belly in females is yellowish-white; the gill covers are transparent. The males will prominently display their unpaired fins to conspecifics.
All fins, save the pectoral fins, show two parallel black lines with a bright red area in between. Females have a weaker version of the pattern in the tail and dorsal fins only, sometimes in the anal fin, too. A courting male develops a red belly and the flanks brighten and darken, making the pearly spots stand out more, with the back appearing paler than the flanks and standing out. A female in reproductive age can be recognized by a black anal spot which separates the belly color from the uniformly reddish base of the anal fin; the male has a small black pad at the edges of the lower jaw, absent or reduced in females. Immature fish show some indication of a striped pattern, which decomposes into the pearly dots; the celestial pearl danio was assumed to be a member of the genus Microrasbora, due to its similarity to "Microrasbora" erythromicron. Less than a year after the discovery of the celestial pearl danio, it was scientifically described and given the genus name Celestichthys. In 2008, a more comprehensive study showed the celestial pearl danio was a member of the genus Danio, with Danio erythromicron and Danio choprae as its closest relatives.
The fish lives in small ponds created by seeping groundwater or overflow from small brooks or springs. Water temperature in January was rather low, but as the habitat is shallow, it would heat up during hot spells, thus D. margaritatus is tolerant of temperatures above the low 20s. As in most water bodies in the Inle drainage, the water is alkaline; the habitat is vegetated with Hydrocharitaceae similar to Elodea. The celestial pearl danio shares its habitat with a few fish species: a Microrasbora similar to M. rubescens, a rosy loach (Yunnanilus a new species, the dwarf snakehead Channa harcourtbutleri. The latter species is the only known significant predator of D. margaritatus. The species is locally fished for food to some extent. A can of some 500 D. margaritatus sold for food fetched about 25 kyat before the fish was discovered for the aquarium trade. The spawning behavior has significant consequences for captive breeding; the celestial pearl danio appears to be adapted to somewhat ephemeral habitats.
It does not have a dedicated spawning season, nor do the females lay continuously. Rather, they produce small batches of around 30 eggs per spawning episode; the time between spawnings is unknown at present. Eggs are not strewn into the water, but they are not deposited in clutches to a prepared surface either. Courting males will try to defend a patch of dense vegetation. While pursuit swimming has been observed, it does not seem to be connected directly to the actual act of reproduction in which the male displays to a passing female, tests her readiness with a brief chase; the pair moves into the substrate and deposits the eggs. Other males noticing reproduction will try to follow the mating pair, either to try to fertilize the eggs with their own sperm or eat them. At 24–25 °C, the larvae hatch after 3–4 days, they are dark and cryptic and for about three days after hatching, they hide away between substrate and detritus and are hard to see. They subsequently become lighter in color and start swimming and feeding on their own.
At some 8–10 weeks after hatching, they undergo metamorphosis to adult form, the color pattern starts to appear from week 12 onwards. Within six months of its appearance in the aquarium trade, the species was falsely reported as having become so rare, collectors were obtaining only a "few dozen fish per day". Only a small number of aquarists managed to breed the fish while nearly all the fish offered for sale were wild-caught; the concern over the wild populations led British fishkeeping magazine Practical Fishkeeping to request that only aquarists prepared to breed the fish should buy any fish they see for sale, to reduce pressure on the wild stocks by diminishing the demand for them in the UK. As the species seems adapted to living in and colonizing small ephemeral pools, it seemed not well able to withstand prolonged and intense exploitation—if the stock in all pools at one location is fished off, it is unclear in how far the fish would be able to
The glowlight danio is a small, schooling fish related to the popular zebrafish Danio rerio. This should not be confused with the GloFish, a trademarked brand of fluorescent zebrafish that appear to glow in the dark under ultraviolet light. Danio choprae is an active danionin species; this species feeds on insects that have fallen into the water, aquatic insect larvae, other small animals. In the aquarium, it accepts, it has a streamlined body marked with a brilliant orange longitudinal band and a series of vertical blue-black bars on the flanks. The fins are edged with yellow. In recent years, it has become quite traded as an aquarium fish, but otherwise has no commercial importance, its common name derives from its similarity to the glowlight tetra, a South American characin only distantly related to this fish. They get on well with all other Danio species except the giant danio. A less traded geographical variant from the Putao area of northern Myanmar, known as the "northern glowlight danio", sometimes is referred to by a fictitious scientific name "Danio putaoensis".
This variant has more vertical bars and longer barbels. Maximum length: 1.25 inches 4 cm Colors: Brown, green, red Temperature preference: 19-24°Celsius pH preference: 6 to 7 Hardness preference: Soft to medium Salinity preference': Fresh water Compatibility: Good Lifespan: Typically one to three years Ease of keeping: Moderate Ease of breeding: Moderate to hard S. L. Hora named this fish Danio choprae after Dr. B. N. Chopra. However, names ending in' - ae' are reserved for Latin names honouring women. Latin names honouring men end with'-i', the fish name sometimes is reported as Danio choprai. "Danio choprai". Integrated Taxonomic Information System. Retrieved 11 March 2006. Glowlight danio on FishBase Danio choprai
In scientific nomenclature, a synonym is a scientific name that applies to a taxon that goes by a different scientific name, although the term is used somewhat differently in the zoological code of nomenclature. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies; this name is no longer in use: it is now a synonym of the current scientific name, Picea abies. Unlike synonyms in other contexts, in taxonomy a synonym is not interchangeable with the name of which it is a synonym. In taxonomy, synonyms have a different status. For any taxon with a particular circumscription and rank, only one scientific name is considered to be the correct one at any given time. A synonym cannot exist in isolation: it is always an alternative to a different scientific name. Given that the correct name of a taxon depends on the taxonomic viewpoint used a name, one taxonomist's synonym may be another taxonomist's correct name. Synonyms may arise whenever the same taxon is named more than once, independently.
They may arise when existing taxa are changed, as when two taxa are joined to become one, a species is moved to a different genus, a variety is moved to a different species, etc. Synonyms come about when the codes of nomenclature change, so that older names are no longer acceptable. To the general user of scientific names, in fields such as agriculture, ecology, general science, etc. A synonym is a name, used as the correct scientific name but, displaced by another scientific name, now regarded as correct, thus Oxford Dictionaries Online defines the term as "a taxonomic name which has the same application as another one, superseded and is no longer valid." In handbooks and general texts, it is useful to have synonyms mentioned as such after the current scientific name, so as to avoid confusion. For example, if the much advertised name change should go through and the scientific name of the fruit fly were changed to Sophophora melanogaster, it would be helpful if any mention of this name was accompanied by "".
Synonyms used in this way may not always meet the strict definitions of the term "synonym" in the formal rules of nomenclature which govern scientific names. Changes of scientific name have two causes: they may be taxonomic or nomenclatural. A name change may be caused by changes in the circumscription, position or rank of a taxon, representing a change in taxonomic, scientific insight. A name change may be due to purely nomenclatural reasons, that is, based on the rules of nomenclature. Speaking in general, name changes for nomenclatural reasons have become less frequent over time as the rules of nomenclature allow for names to be conserved, so as to promote stability of scientific names. In zoological nomenclature, codified in the International Code of Zoological Nomenclature, synonyms are different scientific names of the same taxonomic rank that pertain to that same taxon. For example, a particular species could, over time, have had two or more species-rank names published for it, while the same is applicable at higher ranks such as genera, orders, etc.
In each case, the earliest published name is called the senior synonym, while the name is the junior synonym. In the case where two names for the same taxon have been published the valid name is selected accorded to the principle of the first reviser such that, for example, of the names Strix scandiaca and Strix noctua, both published by Linnaeus in the same work at the same date for the taxon now determined to be the snowy owl, the epithet scandiaca has been selected as the valid name, with noctua becoming the junior synonym. One basic principle of zoological nomenclature is that the earliest published name, the senior synonym, by default takes precedence in naming rights and therefore, unless other restrictions interfere, must be used for the taxon. However, junior synonyms are still important to document, because if the earliest name cannot be used the next available junior synonym must be used for the taxon. For other purposes, if a researcher is interested in consulting or compiling all known information regarding a taxon, some of this may well have been published under names now regarded as outdated and so it is again useful to know a list of historic synonyms which may have been used for a given current taxon name.
Objective synonyms refer to taxa with same rank. This may be species-group taxa of the same rank with the same type specimen, genus-group taxa of the same rank with the same type species or if their type species are themselves objective synonyms, of family-group taxa with the same type genus, etc. In the case of subjective synonyms, there is no such shared type, so the synonymy is open to taxonomic judgement, meaning that th
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. While these definitions may seem adequate, when looked at more they represent problematic species concepts. For example, the boundaries between related species become unclear with hybridisation, in a species complex of hundreds of similar microspecies, in a ring species. Among organisms that reproduce only asexually, the concept of a reproductive species breaks down, each clone is a microspecies. All species are given a two-part name, a "binomial"; the first part of a binomial is the genus.
The second part is called the specific epithet. For example, Boa constrictor is one of four species of the genus Boa. None of these is satisfactory definitions, but scientists and conservationists need a species definition which allows them to work, regardless of the theoretical difficulties. If species were fixed and distinct from one another, there would be no problem, but evolutionary processes cause species to change continually, to grade into one another. Species were seen from the time of Aristotle until the 18th century as fixed kinds that could be arranged in a hierarchy, the great chain of being. In the 19th century, biologists grasped. Charles Darwin's 1859 book The Origin of Species explained how species could arise by natural selection; that understanding was extended in the 20th century through genetics and population ecology. Genetic variability arises from mutations and recombination, while organisms themselves are mobile, leading to geographical isolation and genetic drift with varying selection pressures.
Genes can sometimes be exchanged between species by horizontal gene transfer. Viruses are a special case, driven by a balance of mutation and selection, can be treated as quasispecies. Biologists and taxonomists have made many attempts to define species, beginning from morphology and moving towards genetics. Early taxonomists such as Linnaeus had no option but to describe what they saw: this was formalised as the typological or morphological species concept. Ernst Mayr emphasised reproductive isolation, but this, like other species concepts, is hard or impossible to test. Biologists have tried to refine Mayr's definition with the recognition and cohesion concepts, among others. Many of the concepts are quite similar or overlap, so they are not easy to count: the biologist R. L. Mayden recorded about 24 concepts, the philosopher of science John Wilkins counted 26. Wilkins further grouped the species concepts into seven basic kinds of concepts: agamospecies for asexual organisms biospecies for reproductively isolated sexual organisms ecospecies based on ecological niches evolutionary species based on lineage genetic species based on gene pool morphospecies based on form or phenotype and taxonomic species, a species as determined by a taxonomist.
A typological species is a group of organisms in which individuals conform to certain fixed properties, so that pre-literate people recognise the same taxon as do modern taxonomists. The clusters of variations or phenotypes within specimens would differentiate the species; this method was used as a "classical" method of determining species, such as with Linnaeus early in evolutionary theory. However, different phenotypes are not different species. Species named in this manner are called morphospecies. In the 1970s, Robert R. Sokal, Theodore J. Crovello and Peter Sneath proposed a variation on this, a phenetic species, defined as a set of organisms with a similar phenotype to each other, but a different phenotype from other sets of organisms, it differs from the morphological species concept in including a numerical measure of distance or similarity to cluster entities based on multivariate comparisons of a reasonably large number of phenotypic traits. A mate-recognition species is a group of sexually reproducing organisms that recognize one another as potential mates.
Expanding on this to allow for post-mating isolation, a cohesion species is the most inclusive population of individuals having the potential for phenotypic cohesion through intrinsic cohesion mechanisms. A further development of the recognition concept is provided by the biosemiotic concept of species. In microbiology, genes can move even between distantly related bacteria extending to the whole bacterial domain; as a rule of thumb, microbiologists have assumed that kinds of Bacteria or Archaea with 16S ribosomal RNA gene sequences more similar than 97% to each other need to be checked by DNA-DNA hybridisation to decide if they belong to the same species or not. This concept was narrowed in 2006 to a similarity of 98.7%. DNA-DNA hybri
South Asia or Southern Asia, is a term used to represent the southern region of the Asian continent, which comprises the sub-Himalayan SAARC countries and, for some authorities, adjoining countries to the west and east. Topographically, it is dominated by the Indian Plate, which rises above sea level as Nepal and northern parts of India situated south of the Himalayas and the Hindu Kush. South Asia is bounded on the south by the Indian Ocean and on land by West Asia, Central Asia, East Asia, Southeast Asia; the current territories of Afghanistan, Bhutan, Nepal, India and Sri Lanka form South Asia. The South Asian Association for Regional Cooperation is an economic cooperation organisation in the region, established in 1985 and includes all eight nations comprising South Asia. South Asia covers about 5.2 million km2, 11.71% of the Asian continent or 3.5% of the world's land surface area. The population of South Asia is about 1.891 billion or about one fourth of the world's population, making it both the most populous and the most densely populated geographical region in the world.
Overall, it accounts for about 39.49% of Asia's population, over 24% of the world's population, is home to a vast array of people. In 2010, South Asia had the world's largest population of Hindus and Sikhs, it has the largest population of Muslims in the Asia-Pacific region, as well as over 35 million Christians and 25 million Buddhists. The total area of South Asia and its geographical extent is not clear cut as systemic and foreign policy orientations of its constituents are quite asymmetrical. Aside from the central region of South Asia part of the British Empire, there is a high degree of variation as to which other countries are included in South Asia. Modern definitions of South Asia are consistent in including Afghanistan, Pakistan, Sri Lanka, Nepal and Maldives as the constituent countries. Myanmar is included in Southeast Asia by others; some do not include Afghanistan, others question whether Afghanistan should be considered a part of South Asia or the Middle East. The current territories of Bangladesh and Pakistan, which were the core of the British Empire from 1857 to 1947, form the central region of South Asia, in addition to Afghanistan, a British protectorate until 1919, after the Afghans lost to the British in the Second Anglo-Afghan war.
The mountain countries of Nepal and Bhutan, the island countries of Sri Lanka and Maldives are included as well. Myanmar is added, by various deviating definitions based on substantially different reasons, the British Indian Ocean Territory and the Tibet Autonomous Region are included as well; the common concept of South Asia is inherited from the administrative boundaries of the British Raj, with several exceptions. The Aden Colony, British Somaliland and Singapore, though administered at various times under the Raj, have not been proposed as any part of South Asia. Additionally Burma was administered as part of the Raj until 1937, but is now considered a part of Southeast Asia and is a member state of ASEAN; the 562 princely states that were protected by but not directly ruled by the Raj became administrative parts of South Asia upon joining Union of India or Dominion of Pakistan. Geopolitically, it had formed the whole territory of Greater India,The South Asian Association for Regional Cooperation, a contiguous block of countries, started in 1985 with seven countries – Bangladesh, India, the Maldives, Nepal and Sri Lanka – and added Afghanistan as an eighth member in 2007.
China and Myanmar have applied for the status of full members of SAARC. This bloc of countries include two independent countries that were not part of the British Raj – Nepal, Bhutan. Afghanistan was a British protectorate from 1878 until 1919, after the Afghans lost to the British in the Second Anglo-Afghan war; the World Factbook, based on geo-politics and economy defines South Asia as comprising Afghanistan, Bhutan, British Indian Ocean Territory, Maldives, Nepal and Sri Lanka. The South Asia Free Trade Agreement incorporated Afghanistan in 2011, the World Bank grouping of countries in the region includes all eight members comprising South Asia and SAARC as well, the same goes for the United Nations Children's Fund; the United Nations Statistics Division's scheme of sub-regions include all eight members of the SAARC as part of Southern Asia, along with Iran only for statistical purposes. Population Information Network includes Afghanistan, Burma, Nepal and Sri Lanka as part of South Asia.
Maldives, in view of its characteristics, was admitted as a member Pacific POPIN subregional network only in principle. The Hirschman–Herfindahl index of the United Nations Economic and Social Commission for Asia and the Pacific for the region includes only the original seven signatories of SAARC; the British Indian Ocean Territory is connected to the region by a publication of Jane's for security considerations. The region may include the disputed territory of Aksai Chin, part of the British Indian princely state of Jammu and Kashmir, but is now administered as part of the Chinese autonomous region of Xinjiang; the inclusion of Myanmar in South Asia is without consensus, with many considering it a part of Southeast Asia and others including it within South Asia. Afghanistan was of importance to the British colonial empire after the Second Anglo-Afghan War over 1878–1880. Afghanistan remained a British protectorate until 1919, when a treaty with Vladimir Lenin included the granting of independe