Tidepool Tim says,  “Rock crabs are the most common crab commercially caught in Maine. These guys like the river estuaries, bays, and coves. Their larger cousin, the Jonah crab, is a larger, deeper, and more offshore species. The two look pretty similar.  Today I was towing a net for shrimp - up came the most beautiful pink & red rock crab. I had never seen one so brightly colored.  When I picked him up I learned why. This crab had just molted. It was amazingly soft and touchable. I had seen a lot of soft-shells, but never a rock crab.”