|European Green Shore Crab / Carcinus maenas|
They make a living off the seafloor, dining on worms, molluscs, small crustaceans and any number of bits and pieces that fall their way.
Shore Crabs are euryhaline, meaning they can tolerate a wide range of salinities (4 to 52 %), and survive in temperatures of zero to 30 °C (32 to 86 °F).
This adaptability gives them a very wide range and competitive edge. This fellow is from the chilly waters of central Norway. The ability to eat pretty near anything and survive in extremely cold climates means he'll do quite well beneath the ice this winter.