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What is the purpose of a horseshoe crab’s telson?
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horseshoe crab
Horseshoe crab (Limulus polyphemus).
The horseshoe crab’s telson—a long, sharp tail-spine—serves as a vital tool for movement and navigation. While these animals can swim on their backs by beating their gill flaps, they typically move by plowing through mud. During this process, they arch their bodies and use the telson, in conjunction with their last pair of legs, to push themselves forward.1