More than first meets the eye

A hairy legged surf crab.

The hairy legs are for extra, sensory perception similar to touch. Without the hair the crustaceans shell is too hard to get much meaningful tactile details. The hairs on it function like whiskers on a predators face. They are able to give the crab a sense of what is going on around it.

This comes in handy when maintaining a solid grip in the breaking surf is crucial.