The telson is the last division of the body of a crustacean. Structure of crustaceans As Arthropods crustaceans have a stiff Exoskeleton, which must be shed to allow the animal to grow ( Ecdysis or molting It is not considered a true segment because it does not arise in the embryo from teloblast areas as do real segments. Segmentation in biology refers to the division of some Metazoan bodies and Plant body plans into a series of semi-repetitive segments and the question of It never carries any appendages, but a forked "tail" called the caudal furca is often present. An appendage in the broadest sense is an additional or subsidiary part existing on or added to something which can generally still function if the appendage has never existed or Together with the uropods, the telson forms the tail fan of lobsters, shrimp and other decapods. The decapod Crustacean such as a crab lobster shrimp or prawn is made up of nineteen Body segments grouped into two main body parts the Cephalothorax Clawed lobsters compose a family ( Nephropidae, sometimes also Homaridae) of large marine Crustaceans Lobsters are economically important as True shrimp are swimming decapod Crustaceans classified in the Infraorder Caridea, found widely around the world in both fresh The decapods or Decapoda ( literally means "ten footed") are an order of Crustaceans within the class Malacostraca, including many 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. The Caridoid Escape Reaction, also known as lobstering or tail-flipping, refers to an innate escape mechanism in marine and freshwater Crustaceans Krill can reach speeds of over 60 cm per second by this means. Krill are a type of Shrimp -like marine Invertebrate animal These small Crustaceans are important organisms of the Zooplankton, particularly The trigger time to optical stimulus is, in spite of the low temperatures, only 55 ms. Induction, in Biology, refers to the initiation or cause of a change or process such as the production of a specific Morphogenetic effect in the developing Embryo In Physiology, a stimulus is a detectable change in the internal or external environment A millisecond (from Milli- and Second; abbreviation ms is one thousandth of a Second.
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. The subphylum Chelicerata constitutes one of the major subdivisions of the phylum Arthropoda including the Arachnids Horseshoe crabs and related forms The horseshoe crab or Atlantic horseshoe crab ( Limulus polyphemus) is a marine Chelicerate Arthropod. Scorpions are eight-legged Carnivorous Arthropods They are members of the order Scorpiones within the class Arachnida. 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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