Forcipule

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Plutonium zwierleini - Trecastagni - 1 - Lucio Bonato.jpg

Forcipules are the modified, pincer-like, front legs of centipedes that are used to inject venom into prey. [1] [2] They are the only known examples of front legs acting as venom injectors. [1] [3]

Contents

Nomenclature

Forcipules go by a variety of names in both scientific and colloquial usages. They are sometimes known as poison claws or jaw legs, [4] referencing their evolution from maxillipeds, a term which they are also sometimes known by in the context of centipedes (maxillipeds, maxillipedes). Other names include prehensors, telopodites, and forcipulae (singular forcipula). [5] [6] In the specific case in which the forcipules are used to inject venom, they are called toxicognaths (from toxic + the Greek gnathos , jaw). [7]

The term forcipule references their similarity with forceps. [1]

Scientific illustration of a forcipule Forcipule detail.jpg
Scientific illustration of a forcipule

Anatomy, systematics, and variation

The forcipules of Eupolybothrus cavernicolus (Lithobiidae) Eupolybothrus cavernicolus forcipules.jpg
The forcipules of Eupolybothrus cavernicolus (Lithobiidae)

Forcipules evolved from the maxillipeds – front legs – of centipedes' last common ancestor, believed to be somewhat Scutigeromorph-like. They were initially leg-like, then progressed into a more pincer or claw-like shape, as seen today, and restricted to horizontal movement. [1] The forcipules of modern Scutigeromorphs are the most significantly different in shape: they are more leg-like, and cannot hold prey like they are used among other orders: they are used for envenomation only, making their use more comparable to a knife than a pincer. [8]

References

  1. 1 2 3 4 Dugon, Michel M.; Black, Alexander; Arthur, Wallace (2012-05-01). "Variation and specialisation of the forcipular apparatus of centipedes (Arthropoda: Chilopoda): A comparative morphometric and microscopic investigation of an evolutionary novelty". Arthropod Structure & Development. 41 (3): 231–243. doi:10.1016/j.asd.2012.02.001. ISSN   1467-8039. PMID   22370199.
  2. "Are Centipedes Poisonous? | Do Centipedes Bite or Sting? | Orkin". www.orkin.com. Retrieved 2022-08-23.
  3. Shelley, Rowland M. (March 1999). "Centipedes and Millipedes with Emphasis on North American Fauna". Kansas School Naturalist. 45 (3): 3–16. CiteSeerX   10.1.1.365.8963 . Archived from the original on 2016-11-12.
  4. "Molecular Expressions: Science, Optics & You - Olympus MIC-D: Oblique Gallery - Centipede Poison Claws". micro.magnet.fsu.edu. Retrieved 2022-09-05.
  5. Shelley, Rowland M (March 1999). "Centipedes and Millipedes with an emphasis on North American fauna". The Kansas School Naturalist. 45 (3): 3–15. ISSN   0022-877X via CiteSeerX.
  6. Bonato, Lucio; Edgecombe, Gregory; Lewis, John; Minelli, Alessandro; Pereira, Luis; Shelley, Rowland; Zapparoli, Marzio (2010-11-18). "A common terminology for the external anatomy of centipedes (Chilopoda)". ZooKeys (69): 17–51. doi: 10.3897/zookeys.69.737 . ISSN   1313-2970. PMC   3088443 . PMID   21594038.
  7. "Definition of TOXICOGNATH". www.merriam-webster.com. Retrieved 2022-08-23.
  8. Dugon, Michel M. (2017), Malhotra, Anita (ed.), "Evolution, Morphology, and Development of the Centipede Venom System", Evolution of Venomous Animals and Their Toxins, Toxinology, Dordrecht: Springer Netherlands, pp. 261–278, doi:10.1007/978-94-007-6458-3_1, ISBN   978-94-007-6457-6 , retrieved 2022-08-23