Brittle stars use their five limbs to crawl along the sea floor in a bilateral manner, even though their bodies have radial, not bilateral, symmetry.
Henry Astley at Brown University in Providence, Rhode Island, measured the movements of 13 Ophiocoma echinata brittle stars (pictured). He found that the creatures coordinate their limb movements, rather than having each leg react independently to stimuli. The animals move along the axis of a central limb, held either in front of or behind the body, and turn by re-designating the central limb rather than by rotating the body.
Brittle stars are unusual in having limbs with different, interchangeable roles in locomotion that are not constrained by anatomy.
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Star's five-legged coordination. Nature 485, 419 (2012). https://doi.org/10.1038/485419d