Hackled Orbweavers - Family: Uloboridae
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Also known as Cribellate Orbweavers the Family: Uloboridae contains 285 species in 19 genera. These Orbweavers do make a web but it is not nearly as elaborate as that of the araneoid Orbweavers. Some species produce little more than a few radiating lines without the spiral that orb webs are known for. For many other species the web looks like a big mass of radial lines and a tangled mess pretending to be a spiral, to join them. The web is made from cribellate silk which is not sticky itself but rather the spider relies on the physical (adhesive) properties of the silk that have come about merely by the manner in which the silk was created. (from thousands of extremely fine threads protruding from the spiders' cribellum. The threads are so fine that molecular attraction (Van der Waals' Forces) starts to play a role.
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Uloborid spiders are not venomous. They do have chelicerae but the venom glands have disappeared as a secondary evolutionary outcome. iIn other words, their ancestors did have them but they were lost over time. To subdue their prey the Uloborids wrap it over and over and over, sometimes thousands of times using meters and meters of silk. In the process the prey is flattened and covered in digestive fluids. The digested material is then sucked through all the silk around the prey; filtered, if you like, and consumed by the spider. During this whole process the spiders' mouthparts never actually touch the prey itself.
Hackled Orbweavers have been around for some 145 - 152 My. The oldest fossil having been founs some 60 kilometers east of Dubbo in New South Wales. (See Selden&Beattie, 2013) |
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Among the Hackled Orbweavers there are a number of species that display social behaviour and live communally.. Some in groups of only a few spiders, others in groups as large as hundreds of individuals. It would appear as if these colonies form while the spiders are still very young as colonies can be nymph dominated: i.e. mostly young individuals. Or. they may be adult dominated; i.e. a colony of grown-up spiders. The larger colonies contain males wheras the smaller ones do not which indicates the smaller female only colonies may well be about to disappear altogether.
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Miagrammopes bradleyi (likely occurrence)
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Colourful Rainforest Miagrammopes - Miagrammopes flavus
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Social House Spider - Philoponella congregabilis
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Philoponella variabilis
Bearded-legs Uloborid - Uloborus barbipes
Ninja-star Ceiling Spider - Zosis geniculata
Taxonomy:
Phylum: Arthropoda (Arthropods)
> Subphylum: Chelicerata (Chelicerates)
> Class: Arachnida (Arachnids)
> Order: Aranea (Spiders)
> Suborder: Araneomorphae (Typical Spiders)
> Infraorder: Entelegynea (Entelegyne Spiders)
> Superfamily: Uloboroidea (Hackled Orbweavers and Net-casting Spiders)
> Family: Uloboridae (Hackled Orbweavers)
> Genus: Miagrammopes (Feather-legged Spiders)
> Species: M. bradleyi *
> Species: M. flavus - Colourful Rainforest Miagrammopes
> Genus: Philoponella
> Species: P. congregabilis - Social House Spider
> Species: P. variabilis
> Genus: Uloborus (Feather-legged Spiders)
> Species: U. barbipes - Bearded-legs Uloborid
> Genus: Zosis
> Species: Z. geniculata - Ninja-star Ceiling Spider
* = likely
^ = possibly
References and links:
> Eberhard, W.G. and Zschokke, S., (2022. 'The primary webs of Uloboridae (Araneae),' The Journal of Arachnology, 50(3), 335-350, (published 23 November 2022)
> Framenau, V.W., Baehr, B.C. and Zborowski, P., (2014). 'A Guide to the Spiders of Australia.' New Holland Publishers, Chatswood, N.S.W., Australia.
> Hawthorn, A.C., Opell, B.D., (2002). 'Evolution of adhesive mechanisms in cribellar spider prey capture thread: evidence for van der Waals and hygroscopic forces.' Biological Journal of the Linnean Society. 77 (1): 1–8. doi:10.1046/j.1095-8312.2002.00099.x.
> Selden, P. and Beattie, R., (2013). 'A spider fossil from the Jurassic Talbragar Fossil Fish Bed of New South Wales.' Alcheringa: An Australasian Journal of Palaeontology. 37. 10.1080/03115518.2013.735072.
> Sewlal, J.-A.N., (2014). 'Observations of Colonies and Responses to Disturbance by the Uloborid Spider Philoponella republicana (Araneae: Uloboridae) at Simla Research Station, Trinidad and Tobago.' Living World, Journal of the Trinidad and Tobago Field Naturalists' Club: 57–58. ISSN 1029-3299.
> Weng, J.-L., Barrantes, G. and Eberhard, W.G., (2007). 'Feeding by Philoponella vicina (Araneae, Uloboridae) and how uloborid spiders lost their venom glands.' Canadian Journal of Zoology. doi:10.1139/z06-149.
https://australian.museum/learn/animals/spiders/hackled-orb-weavers/
https://eol.org/pages/9037/articles
https://en.wikipedia.org/wiki/Van_der_Waals_force#:~:text=8%20External%20links-,Definition,a%20consequence%20of%20quantum%20dynamics).
> Eberhard, W.G. and Zschokke, S., (2022. 'The primary webs of Uloboridae (Araneae),' The Journal of Arachnology, 50(3), 335-350, (published 23 November 2022)
> Framenau, V.W., Baehr, B.C. and Zborowski, P., (2014). 'A Guide to the Spiders of Australia.' New Holland Publishers, Chatswood, N.S.W., Australia.
> Hawthorn, A.C., Opell, B.D., (2002). 'Evolution of adhesive mechanisms in cribellar spider prey capture thread: evidence for van der Waals and hygroscopic forces.' Biological Journal of the Linnean Society. 77 (1): 1–8. doi:10.1046/j.1095-8312.2002.00099.x.
> Selden, P. and Beattie, R., (2013). 'A spider fossil from the Jurassic Talbragar Fossil Fish Bed of New South Wales.' Alcheringa: An Australasian Journal of Palaeontology. 37. 10.1080/03115518.2013.735072.
> Sewlal, J.-A.N., (2014). 'Observations of Colonies and Responses to Disturbance by the Uloborid Spider Philoponella republicana (Araneae: Uloboridae) at Simla Research Station, Trinidad and Tobago.' Living World, Journal of the Trinidad and Tobago Field Naturalists' Club: 57–58. ISSN 1029-3299.
> Weng, J.-L., Barrantes, G. and Eberhard, W.G., (2007). 'Feeding by Philoponella vicina (Araneae, Uloboridae) and how uloborid spiders lost their venom glands.' Canadian Journal of Zoology. doi:10.1139/z06-149.
https://australian.museum/learn/animals/spiders/hackled-orb-weavers/
https://eol.org/pages/9037/articles
https://en.wikipedia.org/wiki/Van_der_Waals_force#:~:text=8%20External%20links-,Definition,a%20consequence%20of%20quantum%20dynamics).
Photographic contributions: