telson

anatomy

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July 14, 2026

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The telson is the terminal segment of the body of an arthropod or segmented worm. In crustaceans, it forms the middle lobe of the tail. The telson is an unsegmented region at the posterior end of the body and may bear two processes that together form the furca. These processes can vary greatly in size, from short to as long as the rest of the body. The telson is one of the fundamental body parts of a crustacean, alongside the acron (an unsegmented presegmental region at the anterior end) and the fused somites that form the head, thorax, and abdomen.12

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apterygote
Modified abdominal structures
…aid in identification of the telson. The Protura, Collembola, and Monura lack cerci. In Diplura a pair of cerci arise from the small terminal segment. Cerci can be long with numerous segments, short with a central duct and terminal pore, or modified into a pair of pincers for holding prey.…
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…aid in identification of the telson. The Protura, Collembola, and Monura lack cerci. In Diplura a pair of cerci arise from the small terminal segment. Cerci can be long with numerous segments, short with a central duct and terminal pore, or modified into a pair of pincers for holding prey.…
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crustacean
General features
…is another unsegmented region, the telson, that may bear two processes, or rami, which together form the furca. These two processes at the tail end of the body vary greatly in form; in many crustaceans they are short, but in some they may be as long as the rest of…
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…is another unsegmented region, the telson, that may bear two processes, or rami, which together form the furca. These two processes at the tail end of the body vary greatly in form; in many crustaceans they are short, but in some they may be as long as the rest of…
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horseshoe crab
Natural history
…a long, sharp tail-spine, or telson. The smoothly arched upper surface of the cephalothorax has a pair of lateral compound eyes and a much smaller median pair of eyes that respond to ultraviolet light. Underneath, the cephalothorax bears six pairs of legs: the first pair, called chelicerae, are used exclusively…
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…a long, sharp tail-spine, or telson. The smoothly arched upper surface of the cephalothorax has a pair of lateral compound eyes and a much smaller median pair of eyes that respond to ultraviolet light. Underneath, the cephalothorax bears six pairs of legs: the first pair, called chelicerae, are used exclusively…
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