purple shore crab moving on a rock

animal animalia arthropoda bahrain beach beauty blending brachyura brown busaiteen camouflage camouflaged claw closeup coast crab creature crustacea crustacean decapoda ecology environment fauna grains hard hemigrapsus legs malacostraca marine moving natural nature nudus ocean ocypode outdoor purple rock sand sandy sea shell shore silca tropical unnoticed varunidae water white wild wildlife