Nephila clavipes

Nephila clavipes
	Female, Jamaica
	Male, Jamaica
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Class:	Arachnida
Order:	Araneae
Infraorder:	Araneomorphae
Family:	Araneidae
Genus:	Nephila
Species:	N. clavipes
Binomial name
	Nephila clavipes; (Linnaeus, 1767) [1]
Synonyms
	Aranea clavipes; Aranea spinimobilis; Aranea longimana; Epeira clavipes; Epeira plumipes; Nephila wilderi; Nephila wistariana; Nephila concolor; Nephila thomensis;

Last updated August 17, 2019

Nephila clavipes is the only species of golden orb-web spider indigenous to continental North and South America. In the United States, it is commonly known as the "banana spider".

North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere. It is also considered by some to be a northern subcontinent of the Americas. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the west and south by the Pacific Ocean, and to the southeast by South America and the Caribbean Sea.

South America is a continent in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. It may also be considered a subcontinent of the Americas, which is how it is viewed in the Spanish and Portuguese-speaking regions of the Americas. The reference to South America instead of other regions has increased in the last decades due to changing geopolitical dynamics.

Physical attributes

N. clavipes has the large size and the long legs with clumps of hair that are typical of the genus. It is large compared to most other members of the genus, and is distinguished by the bright colors of the female abdomen, which changes color as the spider matures.

As is usual among orb-weavers, marked sexual dimorphism occurs in general appearance, but especially in size; in linear measurements, males are one-third to one-fourth the size of females, and they also are more slenderly built. This implies a mass some 1/30th to 1/70th of a large female.

Sexual dimorphism is the condition where the two sexes of the same species exhibit different characteristics beyond the differences in their sexual organs. The condition occurs in many animals and some plants. Differences may include secondary sex characteristics, size, weight, color, markings, and may also include behavioral and cognitive differences. These differences may be subtle or exaggerated, and may be subjected to sexual selection. The opposite of dimorphism is monomorphism.

Etymology

The specific epithet clavipes is derived from the Latin: clava, that variously may mean "knotted staff", "club", or "key"; and pēs meaning "of or pertaining to a foot".^[2]
In assigning the name, Linnaeus apparently referred to the clumps of hair on the legs.

Carl Linnaeus, also known after his ennoblement as Carl von Linné, was a Swedish botanist, zoologist, and physician who formalised binomial nomenclature, the modern system of naming organisms. He is known as the "father of modern taxonomy". Many of his writings were in Latin, and his name is rendered in Latin as Carolus Linnæus.

Distribution and transport

N. clavipes occurs most commonly in the Antilles and in Central America from Mexico in the north through Panama in the south. Less abundantly it occurs as far south as Argentina and in the north it occurs in parts of the southern states of the continental USA. Seasonally, it may range more widely; in summer, it may be found as far north as lower Eastern Canada. Beyond 40° N latitude, these spiders seldom survive the winter.

The Antilles is an archipelago bordered by the Caribbean Sea to the south and west, the Gulf of Mexico to the northwest, and the Atlantic Ocean to the north and east.

Central America is a region found in the southern tip of North America and is sometimes defined as a subcontinent of the Americas. This region is bordered by Mexico to the north, Colombia to the southeast, the Caribbean Sea to the east and the Pacific Ocean to the west and south. Central America consists of seven countries: Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua and Panama. The combined population of Central America is estimated to be between 41,739,000 and 42,688,190.

Mexico, officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatemala, Belize, and the Caribbean Sea; and to the east by the Gulf of Mexico. Covering almost 2,000,000 square kilometers (770,000 sq mi), the nation is the fourth largest country in the Americas by total area and the 13th largest independent state in the world. With an estimated population of over 129 million people, Mexico is the tenth most populous country and the most populous Spanish-speaking country in the world, while being the second most populous nation in Latin America after Brazil. Mexico is a federation comprising 31 states plus Mexico City (CDMX), which is the capital city and its most populous city. Other metropolises in the country include Guadalajara, Monterrey, Puebla, Toluca, Tijuana, and León.

Because humans inadvertently transport spiders as passengers in cargo containers, plant nursery stock, and the like, N. clavipes generally occurs very unevenly over wide areas; often, patches of high local densities are found far from any other populations. Accidental human transport of the species increases markedly in late August to early September, when the spiders' reproduction is at its height.

A nursery is a place where plants are propagated and grown to a desired age. They include retail nurseries which sell to the general public, wholesale nurseries which sell only to businesses such as other nurseries and to commercial gardeners, and private nurseries which supply the needs of institutions or private estates.

The main web of a mature female may be as large as 1 m in diameter, not counting the main filaments that anchor the web between trees; such anchor filaments may be 2-3 m in length. A yellow pigment in the silk lends it a rich, golden glow in suitable lighting. Males come into the female's web for copulation and mate with her, while she is feeding and unable to attack them. After mating, the female spins an egg sac on a tree, laying hundreds of eggs in each sac.

A spider web, spiderweb, spider's web, or cobweb is a structure created by a spider out of proteinaceous spider silk extruded from its spinnerets, generally meant to catch its prey.

In biology, mating is the pairing of either opposite-sex or hermaphroditic organisms, usually for the purposes of sexual reproduction. Some definitions limit the term to pairing between animals, while other definitions extend the term to mating in plants and fungi. Fertilization is the fusion of both sex cell or gamete. Copulation is the union of the sex organs of two sexually reproducing animals for insemination and subsequent internal fertilization. Mating may also lead to external fertilization, as seen in amphibians, fishes and plants. For the majority of species, mating is between two individuals of opposite sexes. However, for some hermaphroditic species, copulation is not required because the parent organism is capable of self-fertilization (autogamy); for example, banana slugs.

Significance to humans

The spider is not aggressive and only bites if handled roughly; the venom is relatively harmless and rarely causes more than slight redness and temporary localized pain.^[3]

A single thread of the anchor silk has a tensile strength of 4×10⁹ N/m², which exceeds that of steel by a factor of eight (ultimate strength of steel 500x10⁶ N/m²).

The silk of N. clavipes has recently been investigated to evaluate its usefulness in surgically improving mammalian neuronal regeneration. In vitro experiments showed that a filament of the silk can lead a severed neuron through the body to the site from which it was severed. The silk elicits no reaction from the immune system, and thereby escapes rejection by the host body.^[4]

Research at Iowa State University has shown that N. clavipes silk, specifically in the draglines, has exceptionally high thermal conductivity, exceeding that of most metals.^[5]

Related Research Articles

Spider silk is a protein fibre spun by spiders. Spiders use their silk to make webs or other structures, which function as sticky nets to catch other animals, or as nests or cocoons to protect their offspring, or to wrap up prey. They can also use their silk to suspend themselves, to float through the air, or to glide away from predators. Most spiders vary the thickness and stickiness of their silk for different uses.

Orb-weaver spiders or araneids are members of the spider family Araneidae. They are the most common group of builders of spiral wheel-shaped webs often found in gardens, fields and forests. "Orb" was previously used in English to mean "circular", hence the English name of the group. Araneids have eight similar eyes, hairy or spiny legs, and no stridulating organs.

Austracantha is a genus of spider with a single species, Austracantha minax, commonly known as the jewel spider or the Christmas spider. It is a member of the family Araneidae and is endemic to Australia. They are relatively small spiders, reaching a maximum total body length of only around 12 mm (0.47 in) for females, and 5 mm (0.20 in) for males. Their abdomen has six distinctive projections ("spines") that makes them easy to identify. They are predominantly a shiny black, with variable white, yellow, and orange patterns. Melanistic forms also occur during autumn. They are facultatively gregarious, and can be found in large aggregations of overlapping orb webs. They feed on small flying insects that get entangled in their webs. They are harmless to humans, though the webs can be a nuisance for bushwalkers. They are most abundant during the summer months.

The golden silk orb-weavers (Nephila) are 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 also commonly called golden orb-weavers, giant wood spiders, or banana spiders.

A web decoration or stabilimentum is a conspicuous silk structure included in the webs of some species of orb-web spider. Its function is a subject of debate.

Nephila inaurata, commonly known as the red-legged golden orb-weaver spider or red-legged nephila, is a species of golden orb-weaver spider. It is native to southern and East Africa, besides several islands of the western Indian Ocean.

<i>Nephila clavata</i> species of arachnid

Nephila clavata, also known as the Jorō spider, is a member of the golden orb-web spider genus. The spider can be found throughout Japan except Hokkaidō, in Korea, Taiwan, China, and more recently, Northeast Georgia in North America. Due to the large size as well as the bright, unique colors of the female Nephila, the spider is well-favored in Japan.

Latrodectus hesperus, the western black widow spider or western widow, is a venomous spider species found in western regions of North America. The female's body is 14–16 mm in length and is black, often with an hourglass-shaped red mark on the lower abdomen. This "hourglass" mark can be yellow, and on rare occasions, white. The male of the species is around half this length and generally a tan color with lighter striping on the abdomen. The population was previously described as a subspecies of Latrodectus mactans and it is closely related to the northern species Latrodectus variolus. The species, as with others of the genus, build irregular or "messy" webs: Unlike the spiral webs or the tunnel-shaped webs of other spiders, the strands of a Latrodectus web have no apparent organization.

The spider species Argiope aurantia is commonly known as the yellow garden spider, black and yellow garden spider, golden garden spider, writing spider, zigzag spider,corn spider, or McKinley spider. It is common to the contiguous United States, Hawaii, southern Canada, Mexico, and Central America. It has distinctive yellow and black markings on the abdomen and a mostly white cephalothorax. Its scientific Latin name translates to "gilded silver-face". Males range from 5–9 mm (0.20–0.35 in); females range from 19–28 mm (0.75–1.10 in). These spiders may bite if disturbed or harassed, but the venom is harmless to non-allergic humans, roughly equivalent to a bumblebee sting in intensity.

Nephilinae is a spider subfamily of the family Araneidae with five genera. The various genera in Nephilinae were formerly grouped in the family Nephilidae, and before that in the Tetragnathidae and in the Araneidae. All nephiline genera partially renew their webs.

Nephila edulis is a species of large spider of the Araneidae family. It is referred to the common name Australian golden orb weaver. It is found in Australia, in both tropical and temperate regions, and in parts of New Guinea and New Caledonia.

Nephila pilipes is a species of golden orb-web spider. It can be found in Japan, China, Vietnam, Cambodia, Taiwan, Malaysia, Singapore, Myanmar, Indonesia, Thailand, Laos, Philippines, Sri Lanka, India, Nepal, Papua New Guinea, and Australia. It is commonly found in primary and secondary forests and gardens. Females are large and grow to a body size of 30–50 mm, with males growing to 5–6 mm. It is the largest of the orb-weaving spiders apart from the recently discovered Nephila komaci, and one of the biggest spiders in the world.

Nephilengys is a genus of tropical spiders of the family Araneidae, consisting of two currently described species. The genus Nephilingis has been split off from this genus. Both genera have been called hermit spiders from the habit staying in their retreats during the day; the name eunuch spiders has been used for Nephilengys alone. Males may sever parts of their palpal bulbs after copulation.

Sexual cannibalism practice when a female cannibalizes her mate prior to, during, or after copulation

Sexual cannibalism is when a female cannibalizes her mate prior to, during, or after copulation. It is a phenomenon characterized primarily by members of most arachnid orders, as well as several insect orders. The adaptive foraging hypothesis, aggressive spillover hypothesis and mistaken identity hypothesis are among the proposed hypotheses to explain how sexual cannibalism evolved. This behavior is believed to have evolved as a manifestation of sexual conflict, occurring when the reproductive interests of males and females differ. In many species that exhibit sexual cannibalism, the female consumes the male upon detection. Females of cannibalistic species are generally hostile and unwilling to mate; thus many males of these species have developed adaptive behaviors to counteract female aggression.

Argiope anasuja, is a species of harmless orb-weaver spider found from the Seychelles to India, Pakistan and Sri Lanka, and in the Maldives.

Nephila komaci is a species of golden orb-web spider. It is the largest web-spinning spider known. A few specimens have been found in South Africa and Madagascar.

Darwin's bark spider is an orb-weaver spider that produces the largest known orb webs, ranging from 900 to 28,000 square centimetres, with bridge lines spanning up to 25 metres (82 ft). The spider was discovered in Madagascar in the Andasibe-Mantadia National Park in 2009. Its silk is the toughest biological material ever studied, over ten times tougher than a similarly-sized piece of Kevlar. The species was named in honour of the naturalist Charles Darwin, with the description being prepared precisely 150 years after the publication of The Origin of Species, on 24 November 2009.

Sexual selection in spiders shows how sexual selection explains the evolution of phenotypic traits in spiders. Male spiders have many complex courtship rituals and have to avoid being eaten by the females, with the males of most species survive a few matings, and having short life spans.

Nephila sumptuosa, the red-legged golden orb-web spider, is a species of golden orb-web spider.

References

↑ "Taxon details Nephila clavipes (Linnaeus, 1767)". World Spider Catalog. Natural History Museum Bern. Retrieved 2017-05-14.
↑ Jaeger, Edmund Carroll (1959). A source-book of biological names and terms. Springfield, Ill: Thomas. ISBN 978-0-398-06179-1.
↑ Weems H. V. Jr. and Edwards, G. B. Jr. 2001 (2004 revision). "Golden silk spider", at UF / IFAS Featured Creatures website
↑ Allmeling, C.; Jokuszies, A.; Reimers, K.; Kall, S. & Vogt (2006). "Use of spider silk fibres as an innovative material in a biocompatible artificial nerve conduit". J. Cell. Mol. Med.10(3): pp 770-777.
↑ Xiaopeng Huang, Guoqing Liu, Xinwei Wang. "New Secrets of Spider Silk: Exceptionally High Thermal Conductivity and Its Abnormal Change under Stretching". Advanced Materials, March 2012 (online)

External links

Mating pair
Pictures of N. clavipes (free for noncommercial use)
Gravity favours smaller males : Review of scientific article on why males are much smaller than females

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.

[WSC_s22435-1] "Taxon details Nephila clavipes (Linnaeus, 1767)". World Spider Catalog. Natural History Museum Bern. Retrieved 2017-05-14.

[Jaeger-2] Jaeger, Edmund Carroll (1959). A source-book of biological names and terms. Springfield, Ill: Thomas. ISBN 978-0-398-06179-1.

[3] Weems H. V. Jr. and Edwards, G. B. Jr. 2001 (2004 revision). "Golden silk spider", at UF / IFAS Featured Creatures website

[4] Allmeling, C.; Jokuszies, A.; Reimers, K.; Kall, S. & Vogt (2006). "Use of spider silk fibres as an innovative material in a biocompatible artificial nerve conduit". J. Cell. Mol. Med.10(3): pp 770-777.

[5] Xiaopeng Huang, Guoqing Liu, Xinwei Wang. "New Secrets of Spider Silk: Exceptionally High Thermal Conductivity and Its Abnormal Change under Stretching". Advanced Materials, March 2012 (online)