Yes mate shore crab are lighter in coulor, river crab is always darker probably simply through the environment(water) each crab live in. I have found it is easier to keep shore crab alive even red hot days when flattie bashing, river crab seems to be weaker for some reason. But this doesn't effect how they fish, people get live peelers in the winter and most of these are river crab however people catch fish on these year in year out but i like using sea crab its cleaner and personally i think it fishes amazing in the rights conditions. Frozen and fresh a fish will scoff it either way if it sees it.(codling/Cod they are worser than whiteys they get going in a Big sea)