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Nephila és un gènere d'aranyes araneomorfs de la subfamília dels nefilins (Nephilinae), dins la família dels araneids (Araneidae).[2] Va sé ubicada en els Araneidae per Wunderlich el 2004;[3] fou transferida dels Tetragnathidae als Nephilidae per Kuntner l'any 2006;[4] finalment, fou traslladada dels Nephilidae als Araneidae per Dimitrov et al. el 2017.[5]
Són conegudes com a aranyes de seda d'or a causa del color de la seda que produeixen. Els fils de rosca de la seva teranyina brillen com l'or a la llum del sol. El mascle és prop d'1/5 de la grandària de l'aranya femenina. Les aranyes de seda d'or exhibeixen comportament molt interessant. Amb freqüència, la femella reconstrueix la meitat de la seva tela cada matí. Teixeix els elements radials, després es teixeixen els elements circulars. Quan ha acabat de teixir, torna i completa els esvorancs. A més, les aranyes joves mostren un moviment vibratori quan són aguaitades per un depredador.
Les aranyes de seda daurada es poden trobar des d'Amèrica del Nord fins a Xile, adaptant-se a una gran varietat de climes; són considerades aranyes anuals doncs solen morir després de la còpula.
L'espècie Nephila maculata es troba en la majoria dels països del món, posseeix la teranyina coneguda més resistent, tant que a Indonèsia s'utilitza en l'elaboració de peces de vestir. A més conté propietats coagulants ajudant a la curació de ferides.
Nephila és un gènere d'aranyes araneomorfs de la subfamília dels nefilins (Nephilinae), dins la família dels araneids (Araneidae). Va sé ubicada en els Araneidae per Wunderlich el 2004; fou transferida dels Tetragnathidae als Nephilidae per Kuntner l'any 2006; finalment, fou traslladada dels Nephilidae als Araneidae per Dimitrov et al. el 2017.
Die Seidenspinnen (Nephila) sind eine Gattung tropischer und subtropischer Echter Webspinnen aus der Familie der Seidenspinnen (Nephilidae) und umfassen 23 Arten.[1] (Stand: Juni 2016)
Gelegentlich werden sie Goldene Radnetzspinnen (engl.: golden (silk) orb-weavers) genannt. Ihren englischen Namen silk spider erhielten sie wegen ihrer feinen, aber stabilen Fäden, deren Herstellung auch Gegenstand der Forschung ist. Im konischen Hinterleib, der teilweise auffällig bunt gemustert ist, liegt der Spinnapparat. Er enthält bei den weiblichen Tieren sechs verschiedene Typen von Spinndrüsen. Die Spinnen sind langbeinig und 2 bis 6 cm groß.
Seidenspinnen weben sehr große und stabile Spinnennetze, bei denen die untere Hälfte deutlich ausgeprägter ist. Die Fangspirale verläuft pendelförmig von einer Seite zur anderen. Nur die Hilfsspirale umrundet den gesamten Kreis. Über der Nabe, dem Sitzplatz der Spinne, weben sie einen gewölbten Sonnenschutz zur Thermoregulation, das sogenannte barrier web, welches auch als eine Abwandlung des sogenannten Stabilimentes gesehen wird. Der Faden der Seidenspinnen zeigt insbesondere bei Sonneneinstrahlung einen charakteristischen Goldschimmer.
Bei direkter Sonneneinstrahlung ändern die Spinnen auch ihre Körperhaltung und richten sich in Längsrichtung zu den einfallenden Sonnenstrahlen aus, sodass die exponierte Fläche geringer ist. Möglicherweise bieten auch die Guanineinlagerungen, welche die auffälligen Muster auf dem Hinterleib erzeugen, einen Wärmeschutz durch Reflexion. Bei steigender Hitze ziehen sich Seidenspinnen in den Schatten ihres Sonnenschutzes zurück. Bei über 40 °C tritt eine Art Narkosezustand, der Hitzestupor, ein. Bei Kälte wird der Körper quer zur Sonneneinstrahlung ausgerichtet, sodass die Körperoberfläche so viele Sonnenstrahlen wie möglich auffangen kann, wodurch die Körpertemperatur steigt.
Die Seidenspinnen fangen ihre Beute hauptsächlich mit ihren großen Netzen. Verfängt sich ein Tier passender Größe darin, spinnen sie es erst kurz ein und beißen dann zu, um ihr Gift über die Cheliceren zu injizieren. Im Anschluss wird die Beute zur Nabe transportiert und vollständig eingesponnen. Schließlich wird sie zum Fressen vom Netz abgelöst. Dies ist zeitaufwändig, macht aber den sicheren Transport größerer Tiere möglich. Mit ihren sehr festen Netzen können diese Spinnen selbst kleine Vögel erbeuten, was in Australien mit Fotos dokumentiert werden konnte.[2]
Zwischen 1990 und 2006 wurde die Gattung Nephila Leach, 1815 zu der Familie der Echten Radnetzspinnen (Araneidae) gezählt. Im Jahr 2006 übernahm der World Spider Catalog die Einteilung in die revidierte Familie der Seidenspinnen (Nephilidae) auf der Basis der Argumentation von Matjaž Kuntner.[3] Die Gattungen Nephilengys L. Koch, 1872 und Nephilingis Kuntner, 2013 enthalten weitere Arten, die früher zur Gattung Nephila gestellt wurden.
Die Gattung der Seidenspinnen umfasst 23 Arten mit teilweise mehreren Unterarten:[1] (Stand: Juni 2016)
In China wurde in den Daohugou-Schichten, die ins Jura gestellt werden, ein fossiles Weibchen einer Spinnenart gefunden, das in die Gattung Nephila gestellt und Nephila jurassica benannt wurde. Es handelt sich um die größte bisher gefundene fossile Webspinne überhaupt.[4] Allerdings wurden bald Zweifel an der Zuordnung laut, da das Fossil keine Autapomorphien der Seidenspinnen zeigt. Später wurde in denselben Schichten ein Männchen gefunden, dass aufgrund ähnlicher Merkmale als derselben Art zugehörig gewertet wird. An diesem wurde klar erkennbar, dass diese Art nicht zur Gattung Nephila gehört haben kann. Die Art wurde nun, von demselben Autorenteam, in eine eigene, ausgestorbene Gattung Mongolarachne, in einer Familie Mongolarachnidae, gestellt und wird dem entsprechend heute Mongolarachne jurassica genannt. Mongolarachne gehört, der Analyse zufolge, in die Stammgruppe der Radnetzspinnen.[5]
Die Seidenspinnen (Nephila) sind eine Gattung tropischer und subtropischer Echter Webspinnen aus der Familie der Seidenspinnen (Nephilidae) und umfassen 23 Arten. (Stand: Juni 2016)
Gelegentlich werden sie Goldene Radnetzspinnen (engl.: golden (silk) orb-weavers) genannt. Ihren englischen Namen silk spider erhielten sie wegen ihrer feinen, aber stabilen Fäden, deren Herstellung auch Gegenstand der Forschung ist. Im konischen Hinterleib, der teilweise auffällig bunt gemustert ist, liegt der Spinnapparat. Er enthält bei den weiblichen Tieren sechs verschiedene Typen von Spinndrüsen. Die Spinnen sind langbeinig und 2 bis 6 cm groß.
பீமன் சிலந்தி (golden silk orb-weavers, பேரினம்: "நெபீலா", Nephila) ஓர் அபூர்வ வகை பெரிய சிலந்திகள் ஆகும். 165 மில்லியன் ஆண்டுகட்கு முன் வாழ்ந்த நெஃபிலியா ஜீராசிக்கா எனும் சிற்றினம் இது வரை கிடைத்த சிலந்தி புதைபடிமங்களிலேயே பெரியது.[1]
நான்கு முதல் ஆறு அங்குலம் வரை நீளமும் இரண்டு அங்குல அகலமும் உள்ள இச்சிலந்தியின் உடல் நடுவில் மஞ்சள் நிற கோடுகளும், புள்ளிகளும் நிறைந்து காணப்படும். தரையில் இருந்து குறைந்தது ஆறு மீட்டர் வரை உயரத்திற்கு இவை வலை பின்னும். அவ்வாறான வலைகளின் விஸ்தீரணமும், 2 மீட்டர் வரை இருக்கும். இவ்வலைகள் பிற வகை சிலந்திகளின் வலைகளைக் காட்டிலும் நீண்ட நாள் நீடித்து நிற்கக் கூடியவை. சில வெளிநாடுகளில் இந்த வலைகளை கொண்டு சிறிய மீன்களை பிடித்து வருகின்றனர்.
இவ்வலைகளை சேகரித்து, அவற்றை சுருட்டி அதில் இரைகளை வைத்து மீன்களை பிடிப்பதாகத் தெரிகிறது. வனங்கள் செயற்கையாக அழிக்கப்படுவது, தீயில் எரிந்து நாசமாதல் போன்ற பல்வேறு காரணங்களால், இவ்வகை சிலந்தி இனம் அழிந்து வருகிறது. இதன் உடலில் விஷக்கிருமிகள் இருந்தாலும், மனிதர்களை இவ்வகை சிலந்திகள் தீண்டுவதில்லை. இவ்வகை சிலந்திகளில், பெண் சிலந்திகள் தரையில் குழி தோண்டி அதில் முட்டையிடுகின்றன. இவைகள் இனப்பெருக்கத்திற்காக 15 மணி நேரம் வரை சேர்ந்திருக்கும். அடர்ந்த வனங்களில் மட்டுமே இவ்வகை சிலந்திகள் காணப்படும். மனித நடமாட்டம் உள்ள பகுதிகளில் தென்படாது.
பீமன் சிலந்தி (golden silk orb-weavers, பேரினம்: "நெபீலா", Nephila) ஓர் அபூர்வ வகை பெரிய சிலந்திகள் ஆகும். 165 மில்லியன் ஆண்டுகட்கு முன் வாழ்ந்த நெஃபிலியா ஜீராசிக்கா எனும் சிற்றினம் இது வரை கிடைத்த சிலந்தி புதைபடிமங்களிலேயே பெரியது.
நான்கு முதல் ஆறு அங்குலம் வரை நீளமும் இரண்டு அங்குல அகலமும் உள்ள இச்சிலந்தியின் உடல் நடுவில் மஞ்சள் நிற கோடுகளும், புள்ளிகளும் நிறைந்து காணப்படும். தரையில் இருந்து குறைந்தது ஆறு மீட்டர் வரை உயரத்திற்கு இவை வலை பின்னும். அவ்வாறான வலைகளின் விஸ்தீரணமும், 2 மீட்டர் வரை இருக்கும். இவ்வலைகள் பிற வகை சிலந்திகளின் வலைகளைக் காட்டிலும் நீண்ட நாள் நீடித்து நிற்கக் கூடியவை. சில வெளிநாடுகளில் இந்த வலைகளை கொண்டு சிறிய மீன்களை பிடித்து வருகின்றனர்.
இவ்வலைகளை சேகரித்து, அவற்றை சுருட்டி அதில் இரைகளை வைத்து மீன்களை பிடிப்பதாகத் தெரிகிறது. வனங்கள் செயற்கையாக அழிக்கப்படுவது, தீயில் எரிந்து நாசமாதல் போன்ற பல்வேறு காரணங்களால், இவ்வகை சிலந்தி இனம் அழிந்து வருகிறது. இதன் உடலில் விஷக்கிருமிகள் இருந்தாலும், மனிதர்களை இவ்வகை சிலந்திகள் தீண்டுவதில்லை. இவ்வகை சிலந்திகளில், பெண் சிலந்திகள் தரையில் குழி தோண்டி அதில் முட்டையிடுகின்றன. இவைகள் இனப்பெருக்கத்திற்காக 15 மணி நேரம் வரை சேர்ந்திருக்கும். அடர்ந்த வனங்களில் மட்டுமே இவ்வகை சிலந்திகள் காணப்படும். மனித நடமாட்டம் உள்ள பகுதிகளில் தென்படாது.
Nephila is a genus of araneomorph spiders noted for the impressive webs they weave. Nephila consists of numerous species found in warmer regions around the world. They are commonly called golden silk orb-weavers, golden orb-weavers, giant wood spiders, or banana spiders.
The genus name Nephila is derived from Ancient Greek, meaning "fond of spinning",[2] from the words νεῖν (nein) = to spin (related to nema νήμα "thread") + φίλος (philos) = "love".
Nephila spiders vary from reddish to greenish yellow in color with distinctive whiteness on the cephalothorax and the beginning of the abdomen. Like many species of the superfamily Araneoidea, most of them have striped legs specialized for weaving (where their tips point inward, rather than outward as is the case with many wandering spiders). Their contrast of dark brown/black and green/yellow allows warning and repelling of potential predators to which their venom might be of little danger.
Golden orb-weavers reach sizes of 4.8–5.1 cm (1.5–2 in) in females, not including legspan, with males being usually two-thirds smaller (less than 2.5 cm, 1 in). In 2012, a large individual was photographed killing and consuming a 0.5-m-long brown tree snake in Freshwater, Queensland.[3] Species from Taiwan have been known to reach over 130 mm (5.1 in), legspan included, in mountainous country.[4] In 2014, a study discovered that golden orb-weavers living in urban areas, particularly areas of a high socioeconomic status, grew larger and carried more eggs than those in their native habitats. A number of possible explanations were suggested, such as increased food supplies due to artificial light or lack of predators and parasites.[5]
In 2018, twelve Nephila species were reclassified as Trichonephila,[6] with another two (N. kuhlii and N. robusta) considered in 2020 to be junior synonyms of N. pilipes.[7] Species whose placement has been changed by some sources include:
As of October 2021, the World Spider Catalog did not accept all of these changes, listing the following species in the genus Nephila:[1]
Additional fossil species are known from the Cenozoic. In 2012 Geratonephila burmanica was described from the Cenomanian aged Burmese amber, Wunderlich 2015 synonymised Geratonephilia with Nephilia tenuis, a species from the Dominican Amber, as he considered it unlikely that the amber was actually Burmese in origin.[9] Though largely ambiguous, the origins of Nephila are undoubtedly Gondowanan. With the prime candidates being Africa, Indomalaya, and Australasia.[10]
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N. kuhlii dorsal side
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N. kuhlii ventral side
Golden silk orb-weavers are widespread in warmer regions throughout the world, with species in Australia, Asia, Africa (including Madagascar), and the Americas. Spiderlings can be carried by the wind over long distances, and each year, a small number of female golden orb web spiders are found in New Zealand (where they are not endemic) after having been blown across the Tasman Sea; the spiders usually end up in the North Island.[11]
Whilst the geographic distribution of Nephila is large, many habitat similarities are seen between these locations. A warm and reasonably wet climate is generally preferred, as these are some of the environmental cues that induce spiderling hatching.[12] Locally, spiders look for relatively dense vegetation where webs can be set up in areas that insects will regularly fly through. Urban environments are also attractive due to the large prey concentrations and lower levels of predation.[13]
Nephila spiders produce large asymmetric orb webs up to 1.5 m (5 ft) in diameter. Nephila species remain in their webs permanently, so have a higher predation risk. The golden silk orb-weaver is named for the yellow color of the spider silk used to construct these webs.
Yellow threads of their web shine like gold in sunlight. Carotenoids are the main contributors to this yellow color, but xanthurenic acid, two quinones, and an unknown compound may also aid in the color.[14] Experimental evidence suggests that the silk's color may serve a dual purpose: sunlit webs ensnare bees that are attracted to the bright yellow strands, whereas in shady spots, the yellow blends in with background foliage to act as a camouflage. The spider is able to adjust pigment intensity relative to background light levels and color; the range of spectral reflectance is specifically adapted to insect vision.
The webs of most Nephila spiders are complex, with a fine-meshed orb suspended in a maze of non-sticky barrier webs. As with many weavers of sticky spirals, the orb is renewed regularly if not daily, apparently because the stickiness of the orb declines with age. When weather is good (and no rain has damaged the orb web), subadults and adults often rebuild only a portion of the web. The spider removes and consumes the portion to be replaced, builds new radial elements, then spins the new spirals. This partial orb renewal is distinct from other orb-weaving spiders that usually replace the entire orb web. The web of Nephila antipodiana contains ant-repellent chemicals to protect the web.[15]
Typically, the golden orb-weaver first weaves a nonsticky spiral with space for two to 20 more spirals in between (the density of sticky spiral strands decreases with increasing spider size). When she has completed the coarse weaving, she returns and fills in the gaps. Whereas most orb-weaving spiders remove the nonsticky spiral when spinning the sticky spiral, Nephila spiders leave it. This produces a "manuscript paper" effect when the orb is seen in the sun: groups of sticky spirals reflecting light with "gaps" where the nonsticky spiral does not reflect the light.
In relation to the ground, the webs of adults may be woven from eye-level upwards high into the tree canopy. The orb web is usually truncated by a top horizontal support strand, giving it an incomplete look.
Adjacent to one face of the main orb, a rather extensive and haphazard-looking network of guard-strands may be suspended a few centimeters distant across a free space. This network is often decorated with a lumpy string or two of plant detritus and insect carcasses clumped with silk. This "barrier web" may function as a kind of early-warning system for incoming prey or against spider-hunting predators, or as a shield against windblown leaves; it may also be remnants of the owner's previous web. At least one reference explains the suspended debris-chain as a cue for birds to avoid blundering into and destroying the web.
The golden silk orb-weaver targets many different organisms as prey, ranging from small flies and beetles to larger cicadas and locusts. As a result of their strong web structure, small birds and bats can also become trapped and fed upon. Whilst most of the captured prey is relatively small compared to Nephila, the majority of biomass consumed comes from larger, rarer prey. Prey larger than 66% of the captor's size accounts for just 16.5% of prey captured, but 85% of prey consumed, indicating the spider is selective in its feeding habits.[16]
Spiders are notified that potential prey has been caught in the web through vibrations along strands, and these can be followed to the prey location on the web and be used to estimate prey size.[13]
Nephila species also create caches of food for storage, which can be found above the hub of the web and contain up to 15 prey items. These items are arranged in a line vertically and are wrapped in silk to reduce dehydration. Caches are created and grow when prey is readily available and more biomass is available for consumption than is required by the spider. The purpose of caches is to have a backup food source when prey is scarce and occasionally to provide bait to attract more prey to the web.[17] Nephila species may also respond to food shortages by moving their webs, but this is a response to longer periods of prey scarcity than cache creation.[18] Web moving is seen as a result of environmental change, whereas caches occur from environmental fluctuation.
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Nephila spiders display large sexual dimorphism in size, with females being greatly larger than males. Debate exists as to whether this is a result of male dwarfism or female gigantism. Smaller males may be selected for due to the presence of competition for mating. Smaller males are quicker and more nimble, allowing them to be able to catch the females more easily, as well as to escape when threatened. Larger males may have to wait for the female to come close due to their slower speed.[19] Larger females may have been selected for as a result of males using mating plugs upon copulation. Larger individuals reduce the success of these plugs, allowing for multiple mating and reducing the risk of genital mutilation.[20] Gigantism in females is also associated with fecundity, as larger individuals can produce more eggs and therefore increase reproductive success.[21]
When males are fully mature, they leave their webs to search for a suitable female, often using web characteristics to identify potential mates. Often, multiple males attempt to court the same female, thus competition for territory on the web occurs, but is rarely physical, as smaller males surrender area to larger ones. When males approach females, they are often feeding, allowing the males to get closer without an aggressive response and also meaning the female is not moving. On approach, the male makes himself known by tapping on a web strand to ensure the female is amenable before proceeding to mate. When met with aggression, males stop approaching and remain in the same location until the female relaxes or they retreat. Females engage in multiple mating, but no benefit to the offspring occurs as a result of this; however, the energy cost of repelling a male is higher than that of allowing him to copulate.[22] As a result of this, sperm competition occurs through males altering the duration and frequency of mating, with longer mating being proportional to a greater likelihood of success. Sexual cannibalism is uncommon in Nephila as a result of male mating behaviours. By copulating when females are immobile after molting or inactive due to feeding, the males increase their chances of survival. Males also approach from the side of the web opposite the female, increasing the odds of a successful approach.[23] Male Nephila pilipes is reported to have a mate binding behavior to avoid sexual cannibalism.[13] Sexual cannibalism does still occur, but generally is more common with larger males, and from older females.
Females produce an egg sac in the surrounding environs of the web to protect their eggs. The eggs are deposited on a silk platform, then are covered in loose silk to form a sac, which is firmly attached to surrounding vegetation so that it is hidden from the view of predators. It is reported that egg sacs are mostly under leaves and other coverings. However, only Nephila pilipes is different than other Nephila species. They lay eggs in small pits on the ground to avoid parasitism.[13] These sacs can contain from 300 to 3000 eggs, depending on mating success and particular species.[18] Once hatched, the spiderlings inhabit a communal web to begin their lives.
Nephila spiders change their body positioning relative to the sun to maintain internal temperatures at an optimal level. As ambient temperatures increase, the spiders position themselves so the abdomen shades the cephalothorax from the sun. Spiders may also hang from their hind legs as a result of the heat due to a loss of hydrostatic pressure. Conversely, as temperatures cool down, the spiders position themselves perpendicular to the sun to retain as much heat energy as possible. When ambient temperatures reach extreme highs (above 40 °C), they may leave their webs and seek shade in the surrounding environment.[24]
Predation of Nephila species is relatively uncommon; when it does occur, the main group affected are the juvenile individuals. The major predators are birds, but wasps and damselflies also prey upon smaller juveniles.
Nephila species are frequently parasitized by Argyrodes, a genus of very small black-and-silver spiders that are kleptoparasitic. As many as a few dozen may infest a single Nephila web to feed from the host spider's captured prey. The frequent rebuilding or abandoning of webs by Nephila may be a tactic for controlling Argyrodes. Spiny orb-weaver spiders of the genus Gasteracantha also inhabit the webs of Nephila as kleptoparasites.
Egg sacs generally remain free from both predation and parasitism, often due to the close proximity of the mother and how well it is hidden.
Nephila spiderlings leave the egg sac as a result of environmental cues, often warmer and wetter conditions in spring. They then live on a communal web, eating dead siblings and web debris for around a week before dispersing to make individual webs.[12]
Young spiders do not generally build yellow-colored silk, and the young themselves can be easily mistaken for young orchard spiders (Leucauge) in general color and shape (both genera sport silver stripes or patches on their abdomens, described in some references as a form of heat control). The best distinction between Leucauge and Nephila juveniles is web structure: Leucauge species tend to build horizontal orbs that form a perfect circle, whereas Nephila species build vertical, elliptical orbs that are incomplete (missing the portion of the orb over the hub, the center where the spider sits). The latter seem to prefer more open habitat such as second-growth scrub or forest edges. Fences or building overhangs often do just as nicely.
Once they are juvenile, Nephila spiders inhabit their individual webs, then begin their growth by the molting process. The time between molts is called an instar and seven to 12 of these can occur depending on food availability. Ecdysis, the shedding of the exoskeleton, occurs through the formation of a soft exoskeleton inside the current one. Once the old exoskeleton is shed, the new, larger one begins to harden. Ecdysis occurs when the spider's mass becomes too great for the current exoskeleton to support.[25] Male spiders seek out females for copulation and live on their webs. When mating season arrives, both males and females stop molting and remain the same size for the remainder of their lives.
The venom of the golden silk orb-weaver is effective in action on prey, but has not been reported to be of any notable consequence for humans if accidentally bitten. In the literature, Nephila is one of several genera where the venom "must be considered as more or less ineffectual in human beings".[26] That said, the potentially large size of several members of the genus means that they possess relatively strong chelicerae, so any bite can cause some mechanical damage, but only of short-term localised effect for humans. However, further studies of the venom components are needed to better understand pathways associated with any toxicity.
Nephila do not seem to form either beneficial or harmful relationships with humans. Females often construct their webs using human structures as a base for support strands due to their stability. Individuals are often found in urban and suburban environments due to the protection from predation and greater prey availability.[27] As they weave their webs in bushes and near flowers, they might present a nuisance for gardeners or flower pickers. Some nests near fruits may repel or destroy known pests, such as Tephritid fruit flies, without the need to use insecticides. Spiders may bite humans if provoked but more often flee if confronted.
There have been several efforts in the past to produce garments from Nephila silk although none commercially viable.[29] These include two bed hangings that were shown at the 1900 Paris Exhibition.[30] In 2004 a textile designer, Simon Peers, and an entrepreneur, Nicholas Godley managed in three years' work and using 1.2 million Golden silk orb-weavers (collected in the wild and released some 30 minutes later after they produced the silk) to produce a shawl that was exhibited at the American Museum of Natural History in 2009.[31][32] By 2012 they managed to produce a second, bigger garment, a cape, that, together with the shawl, were exhibited at the Victoria and Albert Museum in London.[33] Two shawls and a traditional Madagascan lamba made of this spider silk were included in an exhibition of curios from the natural world in 2021.[34]
Another possible use of Nephila silk lies in tissue engineering. A study from the Medizinische Hochschule Hannover reports that processed Nephila silk is an excellent scaffold material thanks to its biocompatibility, mechanical strengths, and its property to promote cell adhesion and proliferation.[35] In particular, the silk acts as a suitable guiding material for peripheral nerve regrowth.[36]
Fishermen on the coasts of the Indo-Pacific ocean remove Nephila webs and form them into a ball, which is thrown into the water. There it unfolds and is used to catch bait fish.[29]
Nephila is a genus of araneomorph spiders noted for the impressive webs they weave. Nephila consists of numerous species found in warmer regions around the world. They are commonly called golden silk orb-weavers, golden orb-weavers, giant wood spiders, or banana spiders.
Nephila es un género de arañas araneomorfas perteneciente a la familia Araneidae desde 2017 (Dimitrov et al., 2017), fecha en la que fue transferida desde la familia Nephilidae, y conocidas como arañas de seda de oro debido al color de la seda que producen. Los hilos de rosca de su telaraña brillan como el oro a la luz del sol. El macho es cerca de 1/5 del tamaño de la araña hembra. Las arañas de seda de oro exhiben comportamiento muy interesante. Con frecuencia, la hembra reconstruye la mitad de su tela cada mañana. Teje los elementos radiales, después se tejen los elementos circulares. Cuando ha terminado de tejer, vuelve y completa los boquetes. Además, las arañas jóvenes muestran un movimiento vibratorio cuando son acechadas por un depredador.
Este género de araña posee un potente veneno neurotóxico similar al de la viuda negra, aunque de menor potencia, que no resulta letal en humanos. Los síntomas habituales de la mordedura (dolor local, enrojecimiento, ampollas) desaparecen en un intervalo aproximado de 24 horas.
Su seda de araña es estudiada por su alta resistencia, tanto que en Indonesia se utiliza en la elaboración de prendas de vestir.
La especie extinta Nephila jurassica, que vivió hace cerca de 165 millones de años, alcanzaba una anchura de 15 centímetros entre sus patas, siendo así la mayor araña conocida fosilizada.[1]
Muchas especies que formaban este género fueron transferidas al género Trichonephila en 2019.
Nephila es un género de arañas araneomorfas perteneciente a la familia Araneidae desde 2017 (Dimitrov et al., 2017), fecha en la que fue transferida desde la familia Nephilidae, y conocidas como arañas de seda de oro debido al color de la seda que producen. Los hilos de rosca de su telaraña brillan como el oro a la luz del sol. El macho es cerca de 1/5 del tamaño de la araña hembra. Las arañas de seda de oro exhiben comportamiento muy interesante. Con frecuencia, la hembra reconstruye la mitad de su tela cada mañana. Teje los elementos radiales, después se tejen los elementos circulares. Cuando ha terminado de tejer, vuelve y completa los boquetes. Además, las arañas jóvenes muestran un movimiento vibratorio cuando son acechadas por un depredador.
Este género de araña posee un potente veneno neurotóxico similar al de la viuda negra, aunque de menor potencia, que no resulta letal en humanos. Los síntomas habituales de la mordedura (dolor local, enrojecimiento, ampollas) desaparecen en un intervalo aproximado de 24 horas.
Su seda de araña es estudiada por su alta resistencia, tanto que en Indonesia se utiliza en la elaboración de prendas de vestir.
La especie extinta Nephila jurassica, que vivió hace cerca de 165 millones de años, alcanzaba una anchura de 15 centímetros entre sus patas, siendo así la mayor araña conocida fosilizada.
Nephila est un genre d'araignées aranéomorphes de la famille des Araneidae[1].
Ces araignées sont appelées Néphiles.
Les espèces de ce genre se rencontrent en Asie, en Océanie, en Afrique et en Amérique[1].
Les Néphiles de la faune française se rencontrent dans des départements d'Outre-Mer : Nephila inaurata (Walckenaer, 1842) de La Réunion[2],[3], Nephila comorana Strand,1916, de Mayotte[4] endémique des Comores et Nephila (Trichonephila) clavipes (Linnaeus,1767) de Guyane[5].
Ces araignées tissent des toiles de plus d'un mètre de diamètre avec un fil de soie aux nuances dorées. Ces toiles sont les plus grandes du monde.
Elles présentent habituellement un très fort dimorphisme sexuel, le mâle est plusieurs fois plus petit que la femelle[6].
Les toiles de toutes ces espèces hébergent régulièrement de petites Araignées cleptoparasites du genre Argyrodes (Theridiidae)
Selon World Spider Catalog (version 21.0, 15/06/2020)[7] :
Selon World Spider Catalog (version 20.5, 2020)[8] :
Entre 2006[9] et 2017[10], ce genre a été placé dans les Nephilidae.
Le sous-genre Trichonephila a été élevé au rang de genre par Kuntner et al. en 2019[11].
Nephila nigra est synonyme de Nephila inaurata et Nephila maculata est synonyme de Nephila pilipes[1].
Il y a eu des tentatives pour créer des soieries à Madagascar.
Nephila est un genre d'araignées aranéomorphes de la famille des Araneidae.
Ces araignées sont appelées Néphiles.
Nephila is een geslacht van spinnen uit de familie van de zijdespinnen (Nephilidae). De groep wordt soms in de familie der strekspinnen geplaatst. Maar ze wijken af van de strekspinnen: ze worden veel groter. Ze maken ook een indrukwekkend groot web.
Nephila is een geslacht van spinnen uit de familie van de zijdespinnen (Nephilidae). De groep wordt soms in de familie der strekspinnen geplaatst. Maar ze wijken af van de strekspinnen: ze worden veel groter. Ze maken ook een indrukwekkend groot web.
Multimedia w Wikimedia Commons Nephila – rodzaj pająków z rodziny prządkowatych (Nephilidae). Został nazwany w 1815 roku przez Williama Elforda Leacha, może być starszym synonimem rodzaju Heterargiope Kishida, 1931. Obecnie tradycyjnie zalicza się do niego kilkanaście gatunków[2], jednak dane molekularne sugerują, że może on być difiletyczny – wówczas do Nephila powinno włączać się jedynie Nephila pilipes i Nephila constricta. Kwestia polifiletyzmu tego rodzaju jest jednak dyskusyjna[3]. Rodzaj Nephila obejmuje największe pająki tkające sieci na świecie – samice Nephila komaci osiągają długość niemal 4 cm. Przedstawiciele tego rodzaju cechują się znaczącym dymorfizmem płciowym przejawiającym się różnicą rozmiarów. Samice osiągają znacznie większe rozmiary niż samce – najmniej wyraźny dymorfizm tego typu występuje u gatunku Nephila clavata, którego samice są około 2,2 raza większe od samców, zaś największy u Nephila turneri, u którego samice osiągają długość niemal dziesięciokrotnie większą niż samce[4].
Selden, Shih i Ren (2011) zaliczyli do rodzaju Nephila największego znanego kopalnego pająka – żyjący w środkowej jurze (ok. 165 mln lat temu) gatunek Nephila jurassica; w wypadku potwierdzenia takiej pozycji filogenetycznej tego gatunku Nephila byłaby najdłużej istniejącym ze wszystkich znanych rodzajów pająków[5]. Kuntner i in. (2013) sugerują jednak, że nie należy on do rodzaju Nephila ani w ogóle do prządkowatych. Rodzaj Nephila powstał natomiast prawdopodobnie nie mniej niż 16 mln lat temu[3]. W późniejszej publikacji Selden, Shih i Ren (2013) potwierdzili, że N. jurassica nie należy do prządkowatych; autorzy przenieśli go do odrębnego rodzaju Mongolarachne[6].
Nephila – rodzaj pająków z rodziny prządkowatych (Nephilidae). Został nazwany w 1815 roku przez Williama Elforda Leacha, może być starszym synonimem rodzaju Heterargiope Kishida, 1931. Obecnie tradycyjnie zalicza się do niego kilkanaście gatunków, jednak dane molekularne sugerują, że może on być difiletyczny – wówczas do Nephila powinno włączać się jedynie Nephila pilipes i Nephila constricta. Kwestia polifiletyzmu tego rodzaju jest jednak dyskusyjna. Rodzaj Nephila obejmuje największe pająki tkające sieci na świecie – samice Nephila komaci osiągają długość niemal 4 cm. Przedstawiciele tego rodzaju cechują się znaczącym dymorfizmem płciowym przejawiającym się różnicą rozmiarów. Samice osiągają znacznie większe rozmiary niż samce – najmniej wyraźny dymorfizm tego typu występuje u gatunku Nephila clavata, którego samice są około 2,2 raza większe od samców, zaś największy u Nephila turneri, u którego samice osiągają długość niemal dziesięciokrotnie większą niż samce.
Selden, Shih i Ren (2011) zaliczyli do rodzaju Nephila największego znanego kopalnego pająka – żyjący w środkowej jurze (ok. 165 mln lat temu) gatunek Nephila jurassica; w wypadku potwierdzenia takiej pozycji filogenetycznej tego gatunku Nephila byłaby najdłużej istniejącym ze wszystkich znanych rodzajów pająków. Kuntner i in. (2013) sugerują jednak, że nie należy on do rodzaju Nephila ani w ogóle do prządkowatych. Rodzaj Nephila powstał natomiast prawdopodobnie nie mniej niż 16 mln lat temu. W późniejszej publikacji Selden, Shih i Ren (2013) potwierdzili, że N. jurassica nie należy do prządkowatych; autorzy przenieśli go do odrębnego rodzaju Mongolarachne.
Nephila constitui um gênero de aranhas.[1] São muitas vezes chamadas de "aranhas-tecedeiras" ou tecedeiras-de-seda-dourada, e suas espécies foram no passado classificadas como parte de grupos aracniformes de morfologia similar, como Araneidae (em particular, dentro do gênero Argiope). Essas aranhas são notáveis na sofisticação de suas teias, que muitas vezes assumem uma forma "tridimensional".
Nephila constitui um gênero de aranhas. São muitas vezes chamadas de "aranhas-tecedeiras" ou tecedeiras-de-seda-dourada, e suas espécies foram no passado classificadas como parte de grupos aracniformes de morfologia similar, como Araneidae (em particular, dentro do gênero Argiope). Essas aranhas são notáveis na sofisticação de suas teias, que muitas vezes assumem uma forma "tridimensional".
Nephila, sau Păianjeni țesători aurii, este un gen de păianjeni araneomorfi din familia Nephilidae. Genul include cei mai mari păianjeni țesători de pânze. Ei se numesc țesători aurii nu din cauza culorii corpului, ci a firelor de mătase de culoare galbenă, în lumina soarelui căpătând nuanțe aurii. Pe lângă acest nume, sunt numiți și păianjeni banană sau păianjeni gigantici de lemn.
Numele genului Nephila provine de la cuvintele grecești νήμα (nema) - fir, ață, fibră și φίλος (philos) - a iubi, a plăcea; adică iubitori de a țese.
Dimensiunile corpului variază de la 1 până la 4 cm, inclusiv picioarele - 12 cm. Dimorfismul sexual este foarte pronunțat, masculii sunt de 4 - 5 ori mai mici decât femelele. Culoarea corpului e foarte variată. Se întâlnesc reprezentanți cu nuanțe de roșu, portocaliu, galben, argintiu, alb, gri și negru. Contrastul dintre culori avertizează dușmanii despre toxicitatea pe care o prezintă. Opistosoma este voluminoasă și, de regulă, tubulară. Forma alungită mărește suprafața de contact a corpului cu aerul prevenind supraîncălzirea. Vârful picioarelor, în special perechii a treia, posedă ghiare utilizate la țeserea mătase.
Un fapt foarte uimitor, spre deosebire de alți păianjeni, aceștia țes o mătase de culoare galbenă. Reflectând lumina soarelui mătasea strălucește asemenea aurului. Culoare galbenă se datorează prezenței în mătase a acidului xanthurenic, doua chinone și plus o substanță necunoscută. Ultimele experimente demonstrează că această culoare are un efect dublu: atrage unele insecte în plasă, care devin prada păianjenilor și acționează ca un camuflaj pe fonul frunzelor îngălbenite sau uscate. Păianjenul e capabil să modifice componența chimică a mătasei, schimbând astfel și nuanța mătasei, fiind adaptate vederii insectelor.
Păianjenii Nephila construiesc plase complexe cu diferite crenguțe, frunze, cuticula neconsumată a victemelor, ataște la o mică distanță de pânză, îndeplinind rolul unor bariere, care văzute de păsări sau de animale mai mari împiedică distrugerea lor. Pânză este de formă rotundă, țesută din radiare și spirale cu ochiuri puțin neregulate. Ea este reînnoit în mod regulat, pentru a menține adezivitatea la nivelul cuvenit. Când vremea este bună, sunt refăcute doar părțile deteriorate ale pânzei. Păianjenii consumă porțiunea care urmează să fie înlocuită, se țes întâi elemente radiare, apoi spirele noi. Această reînnoire parțială este diferită de ceilalți păianjeni care înlocuioesc întreagă pânza.
Firele radiare sunt nelipicioase, cele spirale alternează una nelipicioasă și 20 lipicioase (adezive)[1] . Mai întâi, păianjenul întinde firele radiare, apoi cele spirale nelipicioase. La urmă în locurile dintre spirele nelipicioase sunt țesute cele lipicioase. Pigmenții galbeni sunt prezenți numai în mătasea adezivă. Densitatea spirelor variază în funcție de mărimea păianjenului.
Pânza este verticală și asimetrică. Firele ce pleacă dinspre centru în sus se unesc într-un smoc comun, formând locul de retragere a păianjenului.
Pe pânzele specie Nephila clavipes s-a observat stabilimentum fabricat din mătase amestecată cu cuticulă rămasă de la năpârlirile anterioare, și dispuse în fâșii radiare, de unde a primit denumirea de pânză năpârlită sau pânză schelet. Nephila edulis, în timpul vântului puternic și în zilele ploioase, desface partea inferioară a pânzei pentru a permite curenților de aer vântului fără să distrugă întreaga plasă.
Datorită mărimii pânzei (la unele specii ea poate avea în diametru până la 1 -2 metri) cât și proprietăților, acești păianjeni au fost văzuți mâncând păsări mici[2] [3].
Pânza specie Nephila clavipes.
Pânza specie Nephila clavipes, Florida.
Pânza specie Nephila inaurata, Madagascar.
Pânza specie Nephila clavata, se observ firele galbene.
Mătasea galbenă în lumina soarelui.
Nephila clavipes, Mascul şi femelă
Coconul ascuns printre frunze
Nephila clavata mâncându-şi prada.
Unele specii (de exemplu Nephila clavipes) devin frecvent victime ale păianjenilor Argyrodes, un gen cu reprezentanți foarte mici albi-argintii. Uneori câteva zeci de indivizi pot infesta o singură pânză, hrănindu-se cu prada prinsă de păianjenul gazdă. Reconstruirea frecventă sau abandonarea pânzei poate fi și o tactică de eliminare a acestor mici paraziți.
Păianjenii tinere nu construiesc pânze din mătase galbenă, de aceea uneori pot fi confundați cu juvenilii Leucauge. Culoarea și forma corpului ambelor genuri se aseamănă, opistosoma posedă dungi argintii. Cea mai mare diferență dintre aceștia constă în structura pânzei. Leucauge tinde să construiască o pânză orizontală, care este un cerc perfect, în timp ce Nephila construiesc pânze verticale, eliptice și asimetrice. La apropierea prădătorilor, tinerii produc vibrația pânzei și în cele din urmă sar pe obiectele din jur[4].
Veninul țesătorilor aurii este foarte puternic, dar neletal pentru om. Aceasta are un efect neurotoxic similară cu cea a Văduvii negre. Mușcătura produce durere locală, roșeață, vezicule care în mod normal dispar într-un interval de 24 de ore. În cazuri rare, s-ar putea declanșa reacții alergice, crampe musculare involuntare, iar la persoanele afectate de astm provoacă difilcutăți în respirație/ respiratorii. Din cauza că genul posedă chelicere puternice, mușcătura ar putea lasă o cicatrice.
Acești păianjeni nu sunt mari dăunători pentru oameni. Construindu-și pânza pe arbuștii și florile din grădini, incomodează sau afectează estetica grădinilor. Însă prezența păianjenului lângă fructe poate respinge dăunătorii, fără a se folosi insecticide.
S-au făcut încercări de a produce haine din mătase. Dar, din punct de vedere comercial, această idee nu a avut succes, materialul rezultat era prea scump și productivitatea păianjenilor era scăzută[5].
La Muzeul American de Istorie Naturală,[6][7] este expusă o pânză țesută de peste 1 milion de țesători aurii (femele). Pescarii de pe coastele Oceanelor Indian și Pacific strâng mătase și meșteșugesc/fac din ea mingi utilizate la pescuit.[5]
Păianjenii țesători aurii sunt răspândiți în regiunile calde din întreaga lume: Australia, Africa, Asia tropicală, insulele din sudul Pacificului, în cele două Americi se găsește o singură specie Nephila clavipes.
Nephila, sau Păianjeni țesători aurii, este un gen de păianjeni araneomorfi din familia Nephilidae. Genul include cei mai mari păianjeni țesători de pânze. Ei se numesc țesători aurii nu din cauza culorii corpului, ci a firelor de mătase de culoare galbenă, în lumina soarelui căpătând nuanțe aurii. Pe lângă acest nume, sunt numiți și păianjeni banană sau păianjeni gigantici de lemn.
Nephila[2] är ett släkte av spindlar som ingår i familjen Nephilidae.[2]
Släktet beskrevs av William Elford Leach 1815.[1] Den första art som beskrevs var Nephila clavipes, vilket skedde redan 1767 av Linné, men han placerade den i ett annat släkte.[3] Typart för släktet, Nephila pilipes beskrevs cirka 30 år senare, 1793 av Johan Christian Fabricius.[1] Övriga släkten inom familjen Nephilidae är Clitaetra, Herennia och Nephilengys.
Arterna inom släktet återfinns oftast i varmare länder och väver gärna enorma nät. De har vanligen ett vitt eller gråaktigt prosoma och randiga, proportionellt mycket långa ben där orange, gul eller rött växlas med svart men det förekommer också arter med enfärgade ben, till exempel Nephila fenestrata, vars ben är svarta.
Artlista i alfabetisk ordning enligt Catalogue of Life[2]:
Nephila är ett släkte av spindlar som ingår i familjen Nephilidae.
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Це незавершена стаття з арахнології.Nephila là một loài nhện araneomorph đang với ý với độ dai của mạng nhện chúng tạo ra. Nhện Nephila bao gồm nhiều loài cá nhân được tìm thấy trên khắp thế giới. Chúng cũng thường được gọi là quả cầu vàng, thợ dệt, nhện gỗ khổng lồ, hoặc nhện chuối. Tại Bắc Mỹ, các loài nhện trong chi này (xem nhện Nephila clavipes) đôi khi được gọi là nhện viết chữ do mô hình zigzag thường xuyên (stabilimenta) được xây dựng vào lưới của chúng, mặc dù xảy ra thường xuyên hơn ở mạng của nhện Argiope, chẳng hạn St Andrew's Cross spider.
Loài N. jurassica, sống khoảng 165 triệu năm trước đây, đã có chiều dài chân khoảng 15 cm, và nhện hóa thạch lớn nhất được biết đến.
Nephila là một loài nhện araneomorph đang với ý với độ dai của mạng nhện chúng tạo ra. Nhện Nephila bao gồm nhiều loài cá nhân được tìm thấy trên khắp thế giới. Chúng cũng thường được gọi là quả cầu vàng, thợ dệt, nhện gỗ khổng lồ, hoặc nhện chuối. Tại Bắc Mỹ, các loài nhện trong chi này (xem nhện Nephila clavipes) đôi khi được gọi là nhện viết chữ do mô hình zigzag thường xuyên (stabilimenta) được xây dựng vào lưới của chúng, mặc dù xảy ra thường xuyên hơn ở mạng của nhện Argiope, chẳng hạn St Andrew's Cross spider.
Loài N. jurassica, sống khoảng 165 triệu năm trước đây, đã có chiều dài chân khoảng 15 cm, và nhện hóa thạch lớn nhất được biết đến.
Кругопряды-нефилы[1] (лат. Nephila; от греч. νήμα+φίλος, «любящий плести»[2]) — род крупных пауков. Пауки, плетущие самые большие паутины.[3] Известны под разными названиями: банановые пауки (banana spiders), golden silk orb-weavers (~золотопряды), гигантские древесные пауки (giant wood spiders) и т. д.
Размер тела (без ног) от 1 до 4 см, размах ног достигает 12 см. Характерен половой диморфизм: самцы в несколько раз мельче самок. Среди жертв, попавшихся в сети этих пауков в Австралии (Квинсленд) отмечены даже мелкие птицы.[4][5]
В ископаемом состоянии известно 6 видов рода Nephila (по состоянию на 2011 год): пять видов из неогена (около 16 млн лет; доминиканский янтарь) и вид Nephila pennatipes из эоцена (около 34 млн лет; Флориссант, США).
Некоторые виды (например, N. clavipes и многие другие) часто преследуются родом Argyrodes, мелких черно-серебристых пауков, являющихся их клептопаразитами. Дюжина этих нахлебников, ворующих корм, могут оккупировать сеть одного своего хозяина. Возможно, поэтому виды часто покидают свои старые сети и плетут новые.
Яд пауков рода Nephila сильный, но не смертелен для людей. Он имеет нейротоксический эффект, подобный таковому у каракурта. Укус причиняет местную боль, покраснение и появление волдырей, которые обычно исчезают в пределах 24-часового интервала. В редких случаях может вызвать аллергические реакции, а у астматиков и дыхательные затруднения. Поскольку род обладает относительно сильным хелицерами, укус может оставить небольшой шрам на тонкой коже (например, на пальцах).
Рыбаки на побережьях Индийского и Тихого океанов собирают сети пауков Nephila и формируют из них шар, который бросают в воду, чтобы поймать рыбу.[6]
Ученые Пенсильванского университета (США) секвенировали полный геном паука кругопряда-нефилы Nephila clavipes. Оказалось, что геном этого паука содержит более 14000 генов, в том числе 28 генов, которые кодируют белки паучьего шелка.[1]
В японском фольклоре сказочный монстр дзёрогумо (絡新婦 дословно «паук-девка», вид монстра или духа) использует пауков Nephila для того чтобы изменить внешность и превратиться в соблазнительную женщину. Она заманивает мужчин в свою паутину, где они и становятся её жертвами. Среди японских арахнологов и энтомологов под именем дзёро подразумеваются или вид Nephila clavata или в более широком смысле два близких рода пауков (Nephila и Argiope).
Австралия, Азия, Африка, Мадагаскар, Америка.
Около 30 видов. До 1990 род Nephila входил в состав семейства Araneidae. В 2006 Норман Платник установил отдельное семейство Nephilidae с учётом ревизии Matjaž Kuntner. Часть видов этого рода вошла в состав рода Nephilengys (L. Koch, 1872; Thetragnathidae).
Кругопряды-нефилы (лат. Nephila; от греч. νήμα+φίλος, «любящий плести») — род крупных пауков. Пауки, плетущие самые большие паутины. Известны под разными названиями: банановые пауки (banana spiders), golden silk orb-weavers (~золотопряды), гигантские древесные пауки (giant wood spiders) и т. д.
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