Traditionally in the kitchen and in food preparation, a crabs lungs where called \"dead mans fingers\", probably for more than the reason that they look like fingers but are the parts that held bacteria etc., that could give you food poisoning. The same principle would apply to the green shore crab that we use for bait (we don\'t use edible crab for bait in Yorkshire, Co Durham and Northumberland do we !). Anyway, once a crab is dead, the lungs deteriorate very rapidly and may taint the rest of the meat. When I freeze crab, if they are very alive then they go into the freezer whole, but if they are about to pop then I shell them and remove the lungs. I can\'t say that one fishes better than the other.
On the subject of food poisoning, how many here realise that the summer favourite, mackerel is also quite poisonous when past it\'s best, which soon comes on a warm day inside a bucket or bin liner. Best out of the water and in the pan within an hour or so. Or you could try it as sushi, take a clean knife and some lemon with you next time, slice a bit of meat from the tail end before cleaning the fish. Not my thing, but the Japanese seem to like their raw fish.