... is a name given to at least two species of large, colourful crab: Grapsus grapsus (a.k.a. the red rock crab or abuete negro – the latter being Spanish for 'black boot') and Percnon gibbesi (a.k.a. the nimble spray crab or urchin crab).
The red rock crab lives on the Pacific coast of the Americas; the nimble spray crab is found there and on both sides of the Atlantic – from the equator, and as far north as Florida or Madeira.
According to the Santa Cruz Galapagos Cruise website, the original Sally Lightfoot was a Caribbean dancer; the crab was named after her "thanks to its agility and her lightfoot way of dancing."
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