A spinneret is a silk-spinning organ of a spider or the larva of an insect. Some adult insects also have spinnerets, such as those borne on the forelegs of Embioptera.[1] Spinnerets are usually on the underside of a spider's opisthosoma, and are typically segmented.[2][3] While most spiders have six spinnerets, some have two, four, or eight.[4] They can move both independently and in concert.
Most spinnerets are not simple structures with a single orifice producing a single thread, but complex structures of many microscopic spigots, each producing one filament. This produces the necessary orientation of the protein molecules, without which the silk would be weak and useless. Spigots can be singular or found in groups, which also permits spiders to combine multiple filaments in different ways to produce many kinds of silk for various purposes. Spinneret morphology can help arachnologists identify the taxon of a specimen and the specific morphology of a spigot can determine its use as well. For example, flagelliform spigot is unique to Araneoidea, and another kind of spigot found in sets of three, referred to as cylindrical gland spots, are found only in females and used for making egg sacs.[5] The desert grass spider, Agelenopsis aperta, has especially prominent spinnerets that extend out of the end of their abdomen.[6]
Various species of spiders use silk extruded from spinnerets to build webs, to transfer sperm, to entrap insects by wrapping it around them, to make egg-cases, to manipulate static electricity in the air, and to fly (ballooning), etc.
Some insect larvae (including silkworms) extrude silk to make a protective cocoon for their metamorphosis. The insects known as web spinners weave silken galleries for protection from predators and the elements while foraging and breeding.[7]
Evolutionedit
Observations suggesting that there might be silk-producing organs on the feet of the zebra tarantula (Aphonopelma seemanni) led to questions about the origins of spinnerets. It was hypothesised that spinnerets in spiders were originally used as climbing aids on the feet and evolved and were used for webmaking at a later time.[8]
The compact spinnerets of Argiope bruennichi; placed ventrally below the posterior.
A barn spider encases her prey in silk emanating from her spinneret seen in the foreground.
Ventral aspect of spinnerets of spider species with unusually long spinnerets.
Referencesedit
^INSECTA: EMBIOPTERA (EMBIIDINA) 2013-12-03 at the Wayback Machine, Retrieved December 1, 2013
^Wiggins, Charlotte (Nov 10, 2013). "Gardening to Distraction: Along came a spider". The Rolla Daily News. Therolladailynews.com. Retrieved December 1, 2013.
^Pechmann, Matthias; Khadjeh, Sara; Sprenger, Frederik; Prpic, Nikola-Michael (2010). "Patterning mechanisms and morphological diversity of spider appendages and their importance for spider evolution". Arthropod Structure and Development. 39 (6): 453–467. doi:10.1016/j.asd.2010.07.007. PMID 20696272.
^Spider Identification – Types of Spiders, Retrieved December 1, 2013
^Coddington, Jonathan A. (Spring 1989). "Spinneret Silk Spigot Morphology: Evidence for the Monophyly of Orbweaving Spiders, Cyrtophorinae (Araneidae), and the Group Theridiidae Plus Nesticidae". The Journal of Arachnology. 17 (1). American Arachological Society: 71–95. JSTOR 3705406. Retrieved 31 August 2020.
^Bradley, Richard A. (2012-12-18), "FAMILY CLUBIONIDAE • Sac Spiders", Common Spiders of North America, University of California Press, pp. 105–106, doi:10.1525/california/9780520274884.003.0014, ISBN978-0-520-27488-4, retrieved 2020-12-08
^Richards, O. W.; Davies, R.G. (1977). Imms' General Textbook of Entomology: Volume 1: Structure, Physiology and Development Volume 2: Classification and Biology. Berlin: Springer. ISBN0-412-61390-5.
spinneret, this, article, about, spider, insect, organ, other, uses, disambiguation, spinneret, silk, spinning, organ, spider, larva, insect, some, adult, insects, also, have, spinnerets, such, those, borne, forelegs, embioptera, usually, underside, spider, op. This article is about the spider or insect organ For other uses see Spinneret disambiguation A spinneret is a silk spinning organ of a spider or the larva of an insect Some adult insects also have spinnerets such as those borne on the forelegs of Embioptera 1 Spinnerets are usually on the underside of a spider s opisthosoma and are typically segmented 2 3 While most spiders have six spinnerets some have two four or eight 4 They can move both independently and in concert The spinnerets of an Australian garden orb weaver spider Black spinneret of Phidippus adumbratus visible below red abdomenMost spinnerets are not simple structures with a single orifice producing a single thread but complex structures of many microscopic spigots each producing one filament This produces the necessary orientation of the protein molecules without which the silk would be weak and useless Spigots can be singular or found in groups which also permits spiders to combine multiple filaments in different ways to produce many kinds of silk for various purposes Spinneret morphology can help arachnologists identify the taxon of a specimen and the specific morphology of a spigot can determine its use as well For example flagelliform spigot is unique to Araneoidea and another kind of spigot found in sets of three referred to as cylindrical gland spots are found only in females and used for making egg sacs 5 The desert grass spider Agelenopsis aperta has especially prominent spinnerets that extend out of the end of their abdomen 6 Various species of spiders use silk extruded from spinnerets to build webs to transfer sperm to entrap insects by wrapping it around them to make egg cases to manipulate static electricity in the air and to fly ballooning etc Some insect larvae including silkworms extrude silk to make a protective cocoon for their metamorphosis The insects known as web spinners weave silken galleries for protection from predators and the elements while foraging and breeding 7 Evolution editObservations suggesting that there might be silk producing organs on the feet of the zebra tarantula Aphonopelma seemanni led to questions about the origins of spinnerets It was hypothesised that spinnerets in spiders were originally used as climbing aids on the feet and evolved and were used for webmaking at a later time 8 nbsp The compact spinnerets of Argiope bruennichi placed ventrally below the posterior nbsp A barn spider encases her prey in silk emanating from her spinneret seen in the foreground nbsp Ventral aspect of spinnerets of spider species with unusually long spinnerets References edit INSECTA EMBIOPTERA EMBIIDINA Archived 2013 12 03 at the Wayback Machine Retrieved December 1 2013 Wiggins Charlotte Nov 10 2013 Gardening to Distraction Along came a spider The Rolla Daily News Therolladailynews com Retrieved December 1 2013 Pechmann Matthias Khadjeh Sara Sprenger Frederik Prpic Nikola Michael 2010 Patterning mechanisms and morphological diversity of spider appendages and their importance for spider evolution Arthropod Structure and Development 39 6 453 467 doi 10 1016 j asd 2010 07 007 PMID 20696272 Spider Identification Types of Spiders Retrieved December 1 2013 Coddington Jonathan A Spring 1989 Spinneret Silk Spigot Morphology Evidence for the Monophyly of Orbweaving Spiders Cyrtophorinae Araneidae and the Group Theridiidae Plus Nesticidae The Journal of Arachnology 17 1 American Arachological Society 71 95 JSTOR 3705406 Retrieved 31 August 2020 Bradley Richard A 2012 12 18 FAMILY CLUBIONIDAE Sac Spiders Common Spiders of North America University of California Press pp 105 106 doi 10 1525 california 9780520274884 003 0014 ISBN 978 0 520 27488 4 retrieved 2020 12 08 Richards O W Davies R G 1977 Imms General Textbook of Entomology Volume 1 Structure Physiology and Development Volume 2 Classification and Biology Berlin Springer ISBN 0 412 61390 5 Gorb SN Niederegger S Hayashi CY Summers AP Votsch W Walther P September 28 2006 Bio materials silk like secretion from tarantula feet Nature 443 7110 407 Bibcode 2006Natur 443 407G doi 10 1038 443407a PMID 17006505 S2CID 4415648 External links editElectron microscope image of spider spinnerets nbsp This spider related article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Spinneret amp oldid 1180335952, wikipedia, wiki, book, books, library,
