Sheetweb and Dwarf Spiders - Family: Linyphiidae
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Sheetweb and Dwarf Spiders are the second largest family of the Araneoid Spiders with 4839 species in 636 genera at present count. The genera are arranged into seven subfamilies, three of which are represented in Australia. Linyphiids are found practically all over the world and generally they are best described as small to very small with body length not often exceeding 3 to 4 mm. As is usually the case, there are exceptions though with the largest Linyphiid spider, Orsonwellus malus, reaching lengths of upto 14 mm. O. malus is a native of one of the Hawaiian islands and it may well be that 'island gigantism' has played a role in this spiders' evolution.
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The Linyphiids are more common in colder climates and can be be found at the base of glaciers. Some even tolerate freezing temperatures. Australia though, is not very rich in diversity when it comes to these spiders. Furthermore, positive ID's are hard to establish. About 70% of all spiders found are juveniles and in the Linyphiidae these juveniles may not resemble the adult form at all. Sexual dimorphism also, can be an obstacle in when trying to identify spiders. In this family, some members may be identified to species, even as juveniles, but in most cases a positive ID to genus is all we may hope for.
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Linyphiidae are also known as Sheet Weavers and Money Spiders. The former due to the shape of the web they make and the latter because of a very old superstition that says they bring financial good fortune. Spiderlings and juveniles of Money Spiders spread from the the nest by using a technique called 'ballooning'. They spin a long strand from their spinnerets which is left to hang free and is eventually picked up by the wind carrying the small spider with it. They can travel considerable distances like this but, of course, they cannot control when or where they may eventually land. It is a perilous means of transportion with a high mortality rate as a result.
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Subfamily: Erigoninae
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Erigone prominens
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Mermessus fradeorum (possible occurrence)
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Black-tailed Ostearius - Ostearius melanopygius
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Subfamily: Linyphiinae
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Australolinyphoa remota
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Bathyphantes montanus
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Laetisia raveni
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Cupid's Money Spider - Laperousea blattifera
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Palaeohyphantes simplicipalpis
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Subfamily: Micronetinae
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True Agyneta - Agyneta vera (possible occurrence)
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Australophantes laetisiformis (possible occurrence)
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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: Linyphiidae (Sheetweb and Dwarf Spiders)
> Subfamily: Erigoninae (Dwarf Spiders)
> Genus: Erigone
> Species: E. prominens
> Genus: Mermessus (Decorated-fanged Linyphiids)
> Species: M. fradeorum ^
> Genus: Ostearius
> Species: O. melanopygius - Black-tailed Ostearius
> Subfamily: Linyphiinae (Sheetweb Weavers)
> Genus: Australolinyphia (Australian Money Spiders)
> Species: A. remota
> Genus: Bathyphantes
> Species: B. montanus
> Genus: Laetisia
> Species: L. raveni
> Genus: Laperousea
> Species: L. blattifera - Cupid's Money Spider
> Genus: Palaeohyphantes
> Species: P. simplicipalpis
> Subfamily: Micronetinae
> Genus: Agyneta
> Species: A. vera - True Agyneta ^
> Genus: Australophantes
> Species: A. laetisiformis ^
* = likely
^ = possibly
References and links:
> Hormiga, G., (2002). 'Orsonwelles, a new genus of giant linyphiid spiders (Araneae) from the Hawaiian Islands.' Invertebrate Systematics 16(3): 369-448. doi:10.1071/IT01026
> Raso, L., Sint, D., Rief, A., Kaufmann, R., and Traugott, M., (2014). 'Molecular Identification of Adult and Juvenile Linyphiid and Theridiid Spiders in Alpine Glacier Foreland Communities.' PLOS ONE 9(7): e101755. https://doi.org/10.1371/journal.pone.0101755
> Tanasevitch, A.V. and Stenchly, K. (2012). 'On linyphiid spiders from Sulawesi, Indonesia (Arachnida, Araneae).' Revue Suisse de Zoologie 119(2): 169-180. doi:10.5962/bhl.part.150023
> Wunderlich, J., (1976). 'Spinnen aus Australien. 2. Linyphiidae (Arachnida: Araneida).' Senckenbergiana Biologica 57: 125-142.
https://en.wikipedia.org/wiki/Island_gigantism#:~:text=Island%20gigantism%20is%20one%20aspect,smaller%20bodies%20(insular%20dwarfism).
https://en.wikipedia.org/wiki/John_Blackwall
https://en.wikipedia.org/wiki/Linyphiidae
https://wsc.nmbe.ch/family/48/Linyphiidae
> Hormiga, G., (2002). 'Orsonwelles, a new genus of giant linyphiid spiders (Araneae) from the Hawaiian Islands.' Invertebrate Systematics 16(3): 369-448. doi:10.1071/IT01026
> Raso, L., Sint, D., Rief, A., Kaufmann, R., and Traugott, M., (2014). 'Molecular Identification of Adult and Juvenile Linyphiid and Theridiid Spiders in Alpine Glacier Foreland Communities.' PLOS ONE 9(7): e101755. https://doi.org/10.1371/journal.pone.0101755
> Tanasevitch, A.V. and Stenchly, K. (2012). 'On linyphiid spiders from Sulawesi, Indonesia (Arachnida, Araneae).' Revue Suisse de Zoologie 119(2): 169-180. doi:10.5962/bhl.part.150023
> Wunderlich, J., (1976). 'Spinnen aus Australien. 2. Linyphiidae (Arachnida: Araneida).' Senckenbergiana Biologica 57: 125-142.
https://en.wikipedia.org/wiki/Island_gigantism#:~:text=Island%20gigantism%20is%20one%20aspect,smaller%20bodies%20(insular%20dwarfism).
https://en.wikipedia.org/wiki/John_Blackwall
https://en.wikipedia.org/wiki/Linyphiidae
https://wsc.nmbe.ch/family/48/Linyphiidae
Photographic contributions: