World Library  
Flag as Inappropriate
Email this Article

Telson

Article Id: WHEBN0001095056
Reproduction Date:

Title: Telson  
Author: World Heritage Encyclopedia
Language: English
Subject: Uropod, Megalograptus, Dendrobranchiata, Scorpion, Sanctacaris
Collection: Arthropod Anatomy, Crustacean Anatomy
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Telson

Diagram highlighting the telson of the prawn Litopenaeus setiferus
Telson (arrow no. 3) of the horseshoe crab Carcinoscorpius rotundicauda

The telson is the posterior-most division of the body of an arthropod. It is not considered a true segment because it does not arise in the embryo from teloblast areas as do real segments. It never carries any appendages, but a forked "tail" called the caudal furca may be present. The shape and composition of the telson differs between arthropod groups.

Contents

  • Crustaceans 1
  • Chelicerates 2
  • Myriapods 3
  • See also 4
  • References 5

Crustaceans

In lobsters, shrimp and other decapods, the telson, along with the uropods forms the tail fan. This is used as a paddle in the caridoid escape reaction ("lobstering"), whereby an alarmed animal rapidly flexes its tail, causing it to dart backwards. Krill can reach speeds of over 60 cm per second by this means. The trigger time to optical stimulus is, in spite of the low temperatures, only 55 milliseconds.

In the Isopoda and Tanaidacea (superorder Peracarida), the last abdominal body segment is fused with the telson, forming a "pleotelson".[1]

Chelicerates

The term telson is widely used for the caudal spine of some chelicerates .[2][3] The chelicerate telson can be clearly seen in a number of fossil species (like in eurypterids) and in extant animals (like the horseshoe crab "tail" and the scorpion sting). Some authorities have urged that the usage of this word in this context be discouraged.[4]

Myriapods

Telson of a millipede, including an epiproct (e), hypoproct (h) and paraprocts (p)

In millipedes, the telson consists of a legless pre-anal body segment (which may contain an posterior extension known as an epiproct), a pair of anal valves (paraprocts) or plates closing off the anus, and a plate below the anus (hypoproct), also known as a subanal scale.[5][6]

In centipedes the telson is the rear-most body segment, posterior to the genital openings, bearing two anal valves.[7]

See also

References

  1. ^ S. J. Keable, G. C. B. Poore & G. D. F. Wilson (October 2, 2002). "Australian Isopoda: Families".  
  2. ^ Richard C. Brusca & Gary J. Brusca (2003). Invertebrates (2nd ed.).  
  3. ^ E. E. Ruppert & R. D. Barnes (1994). Invertebrate Zoology (6th ed.).  
  4. ^ Karl-Ernst Lauterbach (1980). "Schlüsselereignisse in der Evolution des Grundplans der Arachnata (Arthropoda)" [Key events in the evolution of the ground plan of the Arachnata (Arthropoda)]. Abhandlungen des Naturwissenschaftlichen Vereins in Hamburg. NF (in German) 23: 163–327. 
  5. ^ Sierwald, Petra; Bond, Jason E. (2007). "Current Status of the Myriapod Class Diplopoda (Millipedes): Taxonomic Diversity and Phylogeny". Annual Review of Entomology 52 (1): 401–420.  
  6. ^ Mesibov, Robert. "Tail". External Anatomy of Polydesmida. Retrieved 4 November 2013. 
  7. ^ Lewis, J. G. E. (2008). The Biology of Centipedes. (Digitally printed 1st paperback version. ed.). Cambridge:  
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.