Telson

Telson

The telson is the last division of the body of a crustacean. 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 is often present. Together with the uropods, the telson forms the tail fan of lobsters, shrimp and other decapods. These are 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 ms.

The same term "telson" is widely used (e. g. invertebrate textbooks such as Ruppert & Barnes, 1994 and Brusca & Brusca, 2003) for the caudal spine of Chelicerata, clearly seen in a number of fossil species and for example in the horseshoe crabs and the scorpion sting. Usage of this word in this context is discouraged. Lauterbach (1980) provided a fine discussion on this, with many illustrations.

References

*Richard C. Brusca & Gary J. Brusca. 2003. Invertebrates. 2nd edition (January 2003), Sinauer Associates. 936 pages.
*Lauterbach, Karl-Ernst. 1980. Schüsselereignisse in der Evolution des Grundplans der Arachnata (Arthropoda). "Abh. naturwiss. Ver. Hamburg" (NF) 23: 163-327.
*Ruppert, E.E. & R.D. Barnes. 1994. Invertebrate Zoology, 6th Ed, Saunders.


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  • telson — [ tɛlsɔ̃ ] n. m. • 1890; en angl. 1855; mot gr. « limite » ♦ Zool. Dernier anneau de l abdomen, chez les arthropodes. Le telson des scorpions porte l aiguillon. ● telson nom masculin (grec telson, extrémité) Synonyme de pygidium. ● telson… …   Encyclopédie Universelle

  • telson — TELSÓN, telsoane, s.n. 1. Ultimul segment abdominal la raci, care formează, împreună cu apendicele segmentului anterior, înotătoarea codală. 2. Segmentul terminal al cozii scorpionilor, care poartă acul veninos. – Din fr. telson. Trimis de… …   Dicționar Român

  • Telson — (Detail) von Hemimysis anomala. Rechts: Uropod Das Telson (von altgriechisch τέλσον Grenze, in älterer Literatur häufig auch als Pygidium bezeichnet) ist der letzte, den After tragende Körperabschnitt der Gliederfüßer (Arthropoden). Es ist, wie… …   Deutsch Wikipedia

  • telson — 1855, from Gk. telson a limit …   Etymology dictionary

  • Telson — Tel son, n.; pl. {Telsons}. [NL., fr. Gr. ? a boundary, limit.] (Zo[ o]l.) The terminal joint or movable piece at the end of the abdomen of Crustacea and other articulates. See {Thoracostraca}. [1913 Webster] …   The Collaborative International Dictionary of English

  • Telson — Telson, Afterregion der Arthropoden …   Deutsch wörterbuch der biologie

  • telson — sustantivo masculino 1. Área: zoología Segmento último del abdomen de los crustáceos, diferenciado de los restantes y provisto en ocasiones de dos apéndices …   Diccionario Salamanca de la Lengua Española

  • telson — (Del gr. τέλσον, extremo). m. Zool. Último segmento del cuerpo de los crustáceos, que suele ser laminar y está situado a continuación del pleon …   Diccionario de la lengua española

  • telson — [tel′sən] n. [ModL < Gr, a limit, boundary, prob. akin to telos, end: see TELO 2] the last, stinging segment of the body of a scorpion, or a projection of the last body segment, as in many decapod crustaceans …   English World dictionary

  • Telson — Exopodios, endopodios y telson (urópodo de un crustáceo). El telson en una pieza o somita que se encuentra al final del abdomen de muchos artrópodos. No se considera un verdadero segmento porque no está presente en estado embrionario, y es… …   Wikipedia Español

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