Because of the high nutrient content of crabs, the loose connection between the collagen fibers and its growth environment, it provides a rich environment for microbial growth, resulting in a high colony count of fresh crabs, and the content will begin to increase rapidly after death, the longer the time of death, the higher the colony count, and the high colony count will lead to nausea and vomiting, abdominal pain and diarrhea and other symptoms in the eaters.
Additionally, studies have found that sulfur-containing compounds can begin to be detected five hours after a crab dies, at which point the crab will emit a fishy odor, which can also lead to nausea and vomiting if the food is eaten with this odor.
In short, if you want to eat crabs, try to eat live crabs; if you want to eat dead crabs, you must choose the crabs that have just died not more than 5 hours ago, and when cooking, you must cook the crabs to prevent causing gastrointestinal reactions and diarrhea.