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− | [[image:aquarium6.jpg|thumb|left|200px|A freshwater aquarium.]]
| + | {{Taxobox |
− | | + | | color = pink |
− | Fishkeeping is a popular [[hobby]] concerned with keeping [[fish]] in the home [[aquarium]] or garden [[pond]].
| + | | name = Green Swordtail |
− | | + | | status = {{StatusSecure}} |
− | The hobby can be broadly divided into three specific disciplines, [[freshwater]], [[brackish water|brackish]], and [[sea|marine]] (also called saltwater) fishkeeping. '''Freshwater fishkeeping''' is by far the most popular branch of the hobby, with even small pet stores often selling a variety of freshwater fish, such as [[goldfish]], [[guppy|guppies]], and [[freshwater angelfish|angelfish]]. While most freshwater aquaria are set up as [[community tank|'''community tanks''']] containing a variety of peaceful species, many aquarists keep single-species aquaria with a view to breeding. [[Live-bearing aquarium fish|Livebearing]] fish such as mollies and guppies are among the species that are most easily raised in captivity, but aquarists also regularly breed numerous other species, including many types of [[cichlid]], [[catfish]], [[characin]], and [[killifish]].
| + | | image = Xiphophorus_helleri_02.jpg |
− | | + | | image_width = 250px |
− | '''Marine aquaria''' are generally more difficult to maintain and the livestock is significantly more expensive, and as a result this branch of the hobby tends to attract more experienced fishkeepers. However, marine aquaria can be exceedingly beautiful, due to the attractive colours and shapes of the [[corals]] and [[coral reef]] fish kept in them. Temperate zone marine fish are not as commonly kept in home aquaria, primarily because they do not do well at room temperature. An aquarium containing these coldwater species usually needs to be either located in a cool room (such as an unheated basement) or else chilled using a [[refrigeration]] device known as a 'chiller'. | + | | regnum = [[Animal]]ia |
− | | + | | phylum = [[Chordate|Chordata]] |
− | '''Brackish water aquaria''' combine elements of both marine and freshwater fishkeeping, reflecting the fact that these aquaria contain water with a salinity in between that of freshwater and seawater. Fish kept in brackish water aquaria come from habitats with varying salinity, such as [[mangroves]] and [[estuaries]] and do not do well if permanently kept in freshwater aquaria. Although brackish water aquaria are not overly familiar to newcomers to the hobby, a surprising number of species prefer brackish water conditions, including the [[Poecilia|mollies]], many [[gobies]], some [[pufferfish]], [[Monodactylidae|monos]], [[Scatophagidae|scats]], and virtually all the [[Soleidae|freshwater soles]]. | + | | classis = [[Actinopterygii]] |
− | | + | | ordo = [[Cyprinodontiformes]] |
− | Fishkeepers are often known as '''aquarists''', since many of them are not solely interested in keeping fish. Many fishkeepers create freshwater aquaria where the focus is on the [[aquatic plants]] rather than on the fish. Though known as the 'Dutch Aquarium' in some circles, in reference to the pioneering work carried out by European aquarists in designing these sorts of aquaria, one of the most active advocates of the heavily planted aquarium is the Japanese aquarist [[Takashi Amano]]. Marine aquarists very often attempt to recreate the coral reef in their aquaria using large quantities of [[living rock]], porous calcareous rocks encrusted with algae, sponges, worms, and other small marine organisms. Larger corals as well as shrimps, crabs, echinoderms, and molluscs are added later on, once the aquarium has matured, as well as a variety of small fish. Such aquaria are sometimes called '[[reef tank]]s'.
| + | | familia = [[Poeciliidae]] |
− | | + | | genus = ''[[Xiphophorus]]'' |
− | Garden ponds are in some ways similar to freshwater aquaria, but are usually much larger and exposed to the ambient climatic conditions. In the tropics, tropical fish can be kept in garden ponds, but in the cooler regions goldfish, [[koi]], and [[orfe]] are kept instead.
| + | | species = '''''X. hellerii''''' |
− | | + | | binomial = ''Xiphophorus hellerii'' |
− | == The origins of fishkeeping == | + | | binomial_authority = [[Heckel (taxonomy)|Heckel]], [[1848]] |
− | Fish have been raised as food in pools and ponds for thousands of years. In Medieval Europe, [[carp]] pools were a standard feature of estates and monasteries, providing an alternative to meat on [[Calendar of saints|feast days]] when meat could not be eaten for religious reasons. Similarly, throughout Asia there is a long history of stocking [[rice paddies]] with freshwater fish suitable for eating, including various types of catfish and cyprinid. Particularly brightly coloured or tame specimens of fish in these pools have sometimes been valued as pets rather than food, and some of these have given rise to completely domesticated varieties, most notably the goldfish and the koi carp, which have their origins in China and Japan respectively.
| + | }} |
− | | + | :''For the genus of butterflies commonly known as swordtails, see [[Graphium]].'' |
− | Marine fish have been similarly valued for centuries, and many wealthy [[ancient Rome|Romans]] kept [[lamprey]]s and other fish in salt water pools. [[Cicero]] reports that the [[advocate]] [[Hortensius |Quintus Hortensius]] wept when a favoured specimen died, while [[Tertullian]] reports that Asinius Celer paid 8000 sesterces for a particularly fine [[Mullet (fish)|mullet]].
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− | == Modern fishkeeping ==
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− | Although some tropical fish were kept in gas-heated tanks in [[Victorian times]], tropical fishkeeping only really became popular from the 1930s onwards when devices like electric heaters and inexpensive glass aquaria became available. Air transportation has also made it possible for fish to be imported from many parts of the world rapidly and inexpensively. As a result, aquarists are routinely offered large numbers of freshwater fish collected from South America, South East Asia, and East Africa. However, the majority of freshwater fish sold to aquarists are commercially bred, primarily in South East Asia and Florida.
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− | Marine fish are not easily bred in captivity, and only a few species, most notably [[seahorses]] and [[clownfish]] are farm-raised. Most are collected from coral reefs, in particular from South East Asia, the Red Sea, and the Caribbean.
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− | ==The Fishkeeping Industry==
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− | Worldwide, the fishkeeping hobby is a multi-million dollar industry, and the [[United States]] is considered the largest market in the world, followed by [[Europe]] and [[Japan]]. In [[1994]], 56% of U.S. households had pets, and 10.6% owned ornamental freshwater or saltwater fish, with an average of 8.8 fish per household. In [[1993]], the retail value of the fish hobby in the United States was [[USD|$]]910 million.
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− | From [[1989]] to [[1992]], almost 79% of all U.S. ornamental fish imports arrived from [[Southeast Asia]] and Japan. [[Singapore]], [[Thailand]], the [[Phillipines]], [[Hong Kong]], and [[Indonesia]] were the top five exporting nations. [[South America]] was the second largest exporting region, accounting for 14% of the total annual value. [[Colombia]], [[Brazil]], and [[Peru]] were the major suppliers. The remaining 7% of ornamental fish imports came from other regions of the world.
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− | Approximately 201 million fish worth $44.7 million were imported into the United States in 1992. These fish comprised 1,539 different [[species]]; 730 [[freshwater]] species, and 809 [[saltwater]] species. The freshwater fish accounted for approximately 96% of the total volume and 80% of the total import value. Of the total of all trade, only 32 species had import values over $10,000. These top species were all of freshwater origin and accounted for 58% of the total imported value of the fish. The top imported species are the [[guppy]], [[neon tetra]], [[Southern platyfish|platy]], [[betta]], [[chinese algae eater]], and [[goldfish]].
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− | == Fish breeding ==
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− | Fish breeding is a challenge that many aquarists find attractive. While some species reproduce freely in community tanks, most require special conditions, known as [[spawning triggers]] before they will breed. The majority of fish lay eggs, and the juvenile fish that emerge are very small and need tiny live foods or their substitutes to survive. A fair number of popular aquarium fish are livebearers, and these fish produce small number of relatively large offspring, and these will usually take ground flake food straight away (see article on [[Live-bearing aquarium fish|livebearing aquarium fish]]).
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− | == Conservation and science ==
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− | According to the [[FAO]], at least 90% of aquarium fish are captive bred [http://www.fao.org/documents/show_cdr.asp?url_file=/docrep/005/x4933e/X4933e10.htm]. The rest of the fish are collected from the wild, and provide an especially valuable source of income for people in regions where other high-value [[exports]] may be lacking [http://www.wetwebmedia.com/AqBizSubWebIndex/marlifeuse.htm].
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− | In theory, wild fish should be a good example of a [[renewable resource]] that places value on maintaining the integrity and diversity of the natural habitat: more and better fish can be exported from clean, pristine aquatic habitat than one that has been polluted or otherwise degraded. However, this has not been the case with industries such as [[trapping|fur trapping]], [[logging]], or [[Fishing industry|fishing]] where a similar situation existed. Historically, wild resources have tended to be overexploited rather than managed (see [[Tragedy of the commons|Tragedy of the Commons]]). Moreover, in places where collecting for aquaria is very intensive, there is good evidence that collecting can result in a decline in fish populations. A particular notorious example is to be found on the [[Philippines]], where overfishing and the widespread use of [[cyanide]] to stun the fish has caused a drastic decline in the diversity of the coral reef fish considered most desirable by aquarists [http://www.panda.org/news_facts/newsroom/features/news.cfm?uNewsID=5563].
| + | The '''Green swordtail''' (''Xiphophorus hellerii'') is a [[species]] of [[freshwater]] [[fish]] in [[family (biology)|family]] [[Poecilidae]] of [[order (biology)|order]] [[Cyprinodontiformes]]. It is also called '''Red swordtail'''. A [[live-bearing aquarium fish|live-bearer]], it is closely related to the [[southern platyfish]] or "platy" (''X. maculatus'') and can interbreed with it. It is native to an area of [[North America|North]] and [[Central America]] stretching from [[Veracruz]], [[Mexico]], to northwestern [[Honduras]]. |
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− | On the other hand, breeding programs by aquarists have helped to preserve species that have become rare or extinct in the wild, most notably among the [[Lake Victoria]] cichlids. Some species of aquarium fish have also become important as laboratory animals, with cichlids and [[Poecilia|poecilids]] being especially important for studies on learning, mating, and social behaviour. Aquarists also observe a large number of fishes not otherwise studied, and thereby provide valuable data on the ecology and behaviour of many species.
| + | [[Image:Swordtail cultivar.JPG|thumb|left|Cultivated form of ''X. hellerii.'']] |
| + | The male green swordtail grows to a maximum overall length of 14 [[centimeter|cm]] (5.5 [[inch|in]]) and the female to 16 cm (6.3 in),although when kept in a freshwater aquarium, they will not grow over 5 inches. |
| + | The name "swordtail" derives form the elongated lower lobe of the male's [[caudal fin]] (tailfin). [[Sexual dimorphism]] is moderate, with the female being larger than the male but lacking the "sword". The wild form is olive green in color, with a red or brown lateral stripe and speckles on the [[dorsal fin|dorsal]] and, sometimes, caudal fins. The male's "sword" is yellow, edged in black below. Captive breeding has produced many color varieties, including black, red, and many patterns thereof, for the aquarium hobby. |
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− | == Animal Welfare ==
| + | The green swordtail prefers swift-flowing, heavily-vegetated rivers and streams, but is also found in warm springs and canals. Omnivorous, its diet includes both plants and small [[crustacean]]s, [[insect]]s, and [[annelid]] worms. |
− | At its best, a properly maintained aquarium allows the fish to socialise with their own kind and in many cases breed successfully. This is in marked contrast to the conditions enjoyed by larger animals like [[cats]] and [[dog]]s, which are often kept alone and [[spay|neutered]], and thus unable to experience anything like a natural lifestyle. However, in many cases fish are maintained in the wrong conditions and therefore live short lives and never breed. Inexperienced aquarists often attempt to keep too many fish in their tanks, or introduce too many fish into an immature aquarium, with the result that large numbers of fish sicken and die. This has given the hobby a bad reputation among some animal welfare groups, such as [[PETA]], for treating aquarium fish as nothing more than cheap toys that are simply replaced when they die [http://www.peta.org/factsheet/files/FactsheetDisplay.asp?ID=30].
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− | Marine fish in particular tend to be less resilient during transportation than freshwater fish, and relatively large numbers of them die before they are finally sold to the aquarist. Although the trade in marine fish and corals for aquaria probably represents a minor threat to coral reefs when compared with habitat destruction, fishing for food, and climate change, it is a booming trade and may be a serious problem in specific locations such as the Philippines and Indonesia where most of the collecting is done [http://www.ofish.org/data-area.asp?aid=9823&gid=4838], [http://www.aaas.org/international/africa/coralreefs/index.shtml].
| + | ''X. hellerii'' has become a nuisance pest as an [[introduced species]] in a number of countries. It has caused ecological damage because of its ability to rapidly reproduce in high numbers. Feral populations have established themselves in southern [[Africa]], including [[KwaZulu-Natal Province|Natal]] and eastern [[Transvaal]] in [[South Africa]] and [[Lake Otjikoto]] in [[Namibia]]. |
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− | Goldfish and [[Siamese fighting fish|bettas]] in particular have often been kept in cramped bowls or aquaria that are really far too small for their needs [http://www.peta.org/feat/aquab/]. In some cases fish have been installed in all sorts of inappropriate objects such as the '''AquaBabies Micro Aquaria''', '''Bubble Gear Bubble Bag''' and '''Betta in a Vase''', all of which contain live fish housed in unfiltered and entirely too small quantities of water [http://boeing_dude.tripod.com/id27.htm], [http://www.peta.org/feat/aquab/wycd.html]. These types of products are not really aimed at aquarists but rather at people looking for a novelty gift, and in fact most aquarists abhor them. Similarly, the awarding of goldfish as prizes at [[funfair]]s is traditional in many parts of the world, but has been criticised by aquarists and animal welfare charities alike as cruel and irresponsible, and giving away live-animal prizes such as goldfish was made illegal in the UK in 2004 [http://news.bbc.co.uk/1/hi/magazine/3893889.stm].
| + | One of the most popular [[tropical]] [[aquarium]] fish, the green swordtail has been bred into various hybrid forms for the aquarium hobby due to its hardiness and suitability for community tanks. |
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− | == Controversy ==
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− | Modifying fish to make them more attractive as pets is an increasingly divisive issue. Historically, artificially dyeing fish was fairly common, with [[Ambassidae|glassfish]] for example being injected with fluorescent dyes. The major British fishkeeping magazine, Practical Fishkeeping, has been effective in its campaign to remove these fish from the market by educating retailers and aquarists to the cruelty and health risks involved [http://www.practicalfishkeeping.co.uk/pfk/pages/show_article.php?article_id=72]. On the other hand, genetically modified fish like the [[glofish]] are likely to become increasingly available, particularly in the United States [http://www.glofish.com/], [http://www.ofish.org/data-area.asp?aid=9820&gid=4839].
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− | == Invasive Species ==
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− | Serious problems can occur when fish originally kept in ponds or [[aquaria]] are released into the wild. While [[tropical zone|tropical]] species of fish will not live for long in [[temperate zone]] climates, fish released into places with similar climatic conditions to those that they originally came from can survive and potentially form viable populations. Species that have established themselves in place that they are not native to are called [[exotic species]]. Examples of exotic fish that have become established outside their normal range are the Asian [[snakeheads]] in Hawaii, African [[walking catfish]] in Florida, and goldfish in Australia. Some of these exotic species can become extremely disruptive preying on, or competing with, the native fish (see [[invasive species]]).
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− | == References and further reading ==
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− | * ''Aquarium Atlas, vol. 1'', by Hans A. Baensch and Rudiger Riehl
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− | * ''Brackish Water Fishes'', by Frank Schäfer
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− | * ''The Conscientious Marine Aquarist'', by Robert Fenner
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− | *{{cite journal
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− | | author = Chapman, F.
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− | | coauthors = Sharon A. Fitz-Coy, Eric M. Thunberg, and Charles M. Adams
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− | | journal = Journal of the World Aquaculture Society
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− | | title = United States of America Trade in Ornamental Fish
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− | | volume = 28
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− | | issue = 1
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− | | month = March
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− | | year = 1997
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− | | pages = 1-10
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− | }}
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− | == See also ==
| + | The green swordtail, as the most common of the swordtail species (and in recognition of the fact that many captive-bred color varieties are not green), is typically known simply as the '''swordtail''' in the aquarium hobby. It is often designated ''X. helleri'' (with one ''i''), but authorities consider this an orthographic error and the spelling with two ''i''s is the valid specific epithet. |
− | * [[Aquarium]]
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− | ==External links== | + | == References == |
− | ''Media''
| + | * {{FishBase_species|genus=Xiphophorus|species=hellerii|year=2004|month=October}} |
− | *[http://www.tfhmagazine.com/ Tropical Fish Hobbyist] - Popular American fishkeeping magazine. | + | * {{ITIS|taxon=Xiphophorus hellerii|ID=647013|year=2004|date=9 December}} |
− | *[http://practicalfishkeeping.co.uk/pfk/pages/home.php Practical Fishkeeping] - Popular British fishkeeping magazine. | |
− | ''General Information''
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− | *[http://www.HoustonFishBox.com/ HoustonFishBox.com] - Promotes knowledgeable Freshwater Fishkeeping.
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− | *[http://www.aquahobby.com Age of Aquariums] Promotes responsible fishkeeping internationally since 1997.
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− | *[http://www.wetwebmedia.com/ Wet Web Media] - Large web site covering different aspects of fishkeeping.
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− | *[http://www.fishtankguy.com Fish Tanks] - Setup and maintenance guide for freshwater aquariums.
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− | * [http://www.tropicalfishkeeper.com/ Tropical Fish Keeper] - Information and help on keeping tropical fish.
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− | ''Specific Fishkeeping Disciplines''
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− | *[http://www.planetcatfish.com/ Planet Catfish] - Web site devoted to catfish in aquaria
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− | *[http://homepage.mac.com/nmonks/aquaria/brackfaqpart1.html Brackish Water Aquarium FAQ] - Detailed FAQ on brackish water fish and aquaria.
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− | ''Community''
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− | *[http://www.fishforums.net/ Tropical Fish Forums] - Friendly fishkeeping discussion and advice forum.
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− | *[http://www.CarolinaFishTalk.com Carolina Aquarium Community Forum]
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− | [[Category:Fishkeeping| ]] | + | [[Category:Live-bearing fish]] |
| + | [[Category:Ovoviviparous fish]] |
| + | [[Category:New Zealand introduced freshwater fish]] |
| + | [[Category:Poeciliidae]] |
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− | [[de:Aquaristik]] | + | [[da:Sværddrager]] |
− | [[fr:Aquariophilie]] | + | [[de:Schwertträger]] |
− | [[it:Acquariofilia]] | + | [[fr:Xipho]] |
− | [[pl:Akwarystyka]] | + | [[nl:Zwaarddrager]] |
| + | [[ja:ソードテール]] |
| + | [[pl:Mieczyk Hellera]] |
| + | [[ru:Зелёный меченосец]] |
| + | [[fi:Miekkapyrstö]] |
| + | [[sv:Svärdbärare]] |
| + | [[zh:红剑鱼]] |
Template:Taxobox
- For the genus of butterflies commonly known as swordtails, see Graphium.
The Green swordtail (Xiphophorus hellerii) is a species of freshwater fish in family Poecilidae of order Cyprinodontiformes. It is also called Red swordtail. A live-bearer, it is closely related to the southern platyfish or "platy" (X. maculatus) and can interbreed with it. It is native to an area of North and Central America stretching from Veracruz, Mexico, to northwestern Honduras.
Cultivated form of
X. hellerii.
The male green swordtail grows to a maximum overall length of 14 cm (5.5 in) and the female to 16 cm (6.3 in),although when kept in a freshwater aquarium, they will not grow over 5 inches.
The name "swordtail" derives form the elongated lower lobe of the male's caudal fin (tailfin). Sexual dimorphism is moderate, with the female being larger than the male but lacking the "sword". The wild form is olive green in color, with a red or brown lateral stripe and speckles on the dorsal and, sometimes, caudal fins. The male's "sword" is yellow, edged in black below. Captive breeding has produced many color varieties, including black, red, and many patterns thereof, for the aquarium hobby.
The green swordtail prefers swift-flowing, heavily-vegetated rivers and streams, but is also found in warm springs and canals. Omnivorous, its diet includes both plants and small crustaceans, insects, and annelid worms.
X. hellerii has become a nuisance pest as an introduced species in a number of countries. It has caused ecological damage because of its ability to rapidly reproduce in high numbers. Feral populations have established themselves in southern Africa, including Natal and eastern Transvaal in South Africa and Lake Otjikoto in Namibia.
One of the most popular tropical aquarium fish, the green swordtail has been bred into various hybrid forms for the aquarium hobby due to its hardiness and suitability for community tanks.
The green swordtail, as the most common of the swordtail species (and in recognition of the fact that many captive-bred color varieties are not green), is typically known simply as the swordtail in the aquarium hobby. It is often designated X. helleri (with one i), but authorities consider this an orthographic error and the spelling with two is is the valid specific epithet.
References
da:Sværddrager
de:Schwertträger
fr:Xipho
nl:Zwaarddrager
ja:ソードテール
pl:Mieczyk Hellera
ru:Зелёный меченосец
fi:Miekkapyrstö
sv:Svärdbärare
zh:红剑鱼