close-up view of a crab observing its environment at the shoreline during low tide

crab shore coastline tide sand beach marine life wildlife closeup nature environment observing seaside claws shell habitat ocean underwater crustacean aquatic sandy animal behavior low natural light coastal invertebrate ecosystem organism biology wild clear scuttling pattern texture blue crustaceans shoreside exploration macro close view shoreline sits still wet positioned defensively scans surroundings contrasts smooth backdrop