Golden Orbweavers - Family: Nephilidae
Photo by Erik Beringen
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First described in 1894 by Eugene Simon, the renowned French naturalist, the Golden Orbweavers are large to very large, colourful spiders that construct enormous webs from strong silk that under certain viewing conditions has a golden sheen to it. They can be found in the warmer regions around the globe. There are currently 58 species in 7 genera listed in the World Spider Catalog but their phylogeny is by no means agreed upon by all. The last 6 to 7 years in particular has seen a lot of disagreement on whether or not the Nephiladae were to be seen as a subfamily of the Aranaeidae or as a family in their own right. The last word on the matter was had only this year by Kuntner et al (2023). As well as that, individual genera and species have moved around a bit.
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Of the seven genera, four are represented in Australia. Three species from two genera are found in the Northern Rivers. Members of this family display extreme sexual dimorphism. Females of the Giant Golden Orbweaver, until recently the largest web-weaving spider known, may reach a bodylength of up to 50 mm. Males on the other hand, do not usually grow beyond 5 - 6 mm, only 1/10th the size of the female. The web of some Nepilids is strong enough for Indigenous peoples of P.N.G. as well as of northern Queensland to have used it when fishing, either as bait, tangled up, or as a net. (Presumably scooped up whole between two long sticks creating a 'net with handles'.)
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Nephilidae are somewhat of a bilogical oddity in that body size evolution of both female and male spiders appears to not only have occurred independently of each other, it also appears to move in opposite directions. And it is a preference towards male dwarfism, rather than a tendency towards female gigantism, that has resulted in the extreme sexual dimorphism between the sexes. Over the years various theories have been suggested for this trait and the most current proposition is that the size difference between males and females as well as the tendency for males to become smaller is closely related to the mating habits of nephilid spiders in general. Most mating takes place during the moulting process of the female, when she is somewhat incapacitated, so finding a female at that particular point in time is a result of stealth, speed and good fortune. Male to male competition, and therefore the need for size and strength, does not really come into play.
(For more on this, see: Scramble competition.) |
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Giant Golden Orbweaver - Nephila pilipes
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Australian Golden Orbweaver - Trichonephila edulis
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Tiger Spider - Trichonephila plumipes
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C 634 - E.Beringen
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Taxonomy:
Phylum: Arthropoda (Arthropods)
> Subphylum: Chelicerata (Chelicerates)
> Class: Arachnida (Arachnids)
> Order: Aranea (Spiders)
> Suborder: Araneomorphae (Typical Spiders)
> Infraorder: Entelegynea (Entelegyne Spiders)
> Superfamily: Araneoidea (Araneoid Spiders)
> Family: Nephilidae (Golden Orbweavers)
> Genus: Nephila
> Species: N. pilipes - Giant Golden Orbweaver
> Genus: Trichonephila
> Species: T. edulis - Australian Golden Orbweaver
> Species: T. plumipes - Tiger Spider
* = likely
^ = possibly
References and links:
> Danielson-François, A., Chueh Hou, Cole, N. and I-Min Tso, (2012). 'Scramble competition for moulting females as a driving force for extreme male dwarfism in spiders,' Animal Behaviour, Volume 84, Issue 4, 2012, Pages 937-945, ISSN 0003-3472, doi.org/10.1016/j.anbehav.2012.07.018
> Kuntner, M., Čandek, K., Gregorič, M., Turk, E., Hamilton, C.A., Chamberland, L., Starrett, J., Cheng, R.C., Coddington, J.A., Agnarsson, I. and Bond, J.E., (2023). 'Increasing information content and diagnosability in family-level classifications.' Systematic Biology 72(4): 964-971. doi:10.1093/sysbio/syad021
> Kuntner, M. and Coddington, J.A., (2009). 'Discovery of the largest orbweaving spider species: the evolution of gigantism in Nephila.' PLoS One 4(10, e7516): 1-5.
doi:10.1371/journal.pone.0007516
> Kuntner, M., Hamilton, C.A., Cheng, R.C., Gregorič, M., Lupse, N., Lokovsek, T., Lemmon, E.M., Lemmon, A.R., Agnarsson, I., Coddington, J.A. and Bond, J.E.. (2019). 'Golden orbweavers ignore biological rules: phylogenomic and comparative analyses unravel a complex evolution of sexual size dimorphism.' Systematic Biology 68(4): 555-572. doi:10.1093/sysbio/syy082
> Vis, C.W. de, (1911). 'A fisherman's spider.' Annals of the Queensland Museum 10: 167-168.
https://en.wikipedia.org/wiki/Eug%C3%A8ne_Simon
https://en.wikipedia.org/wiki/Nephila_komaci
https://en.wikipedia.org/wiki/Phylogenetics
https://en.wikipedia.org/wiki/Scramble_competition
https://en.wikipedia.org/wiki/Sexual_dimorphism
> Danielson-François, A., Chueh Hou, Cole, N. and I-Min Tso, (2012). 'Scramble competition for moulting females as a driving force for extreme male dwarfism in spiders,' Animal Behaviour, Volume 84, Issue 4, 2012, Pages 937-945, ISSN 0003-3472, doi.org/10.1016/j.anbehav.2012.07.018
> Kuntner, M., Čandek, K., Gregorič, M., Turk, E., Hamilton, C.A., Chamberland, L., Starrett, J., Cheng, R.C., Coddington, J.A., Agnarsson, I. and Bond, J.E., (2023). 'Increasing information content and diagnosability in family-level classifications.' Systematic Biology 72(4): 964-971. doi:10.1093/sysbio/syad021
> Kuntner, M. and Coddington, J.A., (2009). 'Discovery of the largest orbweaving spider species: the evolution of gigantism in Nephila.' PLoS One 4(10, e7516): 1-5.
doi:10.1371/journal.pone.0007516
> Kuntner, M., Hamilton, C.A., Cheng, R.C., Gregorič, M., Lupse, N., Lokovsek, T., Lemmon, E.M., Lemmon, A.R., Agnarsson, I., Coddington, J.A. and Bond, J.E.. (2019). 'Golden orbweavers ignore biological rules: phylogenomic and comparative analyses unravel a complex evolution of sexual size dimorphism.' Systematic Biology 68(4): 555-572. doi:10.1093/sysbio/syy082
> Vis, C.W. de, (1911). 'A fisherman's spider.' Annals of the Queensland Museum 10: 167-168.
https://en.wikipedia.org/wiki/Eug%C3%A8ne_Simon
https://en.wikipedia.org/wiki/Nephila_komaci
https://en.wikipedia.org/wiki/Phylogenetics
https://en.wikipedia.org/wiki/Scramble_competition
https://en.wikipedia.org/wiki/Sexual_dimorphism
Photographic contributions:
Beringen, Erik. C 540 - C 613 - C 634.
Beringen, Erik. C 540 - C 613 - C 634.