Shellfish mostly have this fluff, long tide ebb and flow of water back and forth to bring a variety of micro-organisms are sucked and stuck in these fluff, these micro-organisms have become part of the food of the shellfish; these shellfish fish out of the water, because of these with bacteria and micro-organisms see sunlight and air also oxidized black, that is, once you see it, you feel nauseous for the sake of the; in fact, it's really dirty, after buying back to the must be used to carefully clean the brush to be able to Cooking, some allergies after eating, diarrhea are not cleaned due to the previous epidemic in Shanghai, "Hepatitis B" epidemic infection, and finally proved that the source of the disease comes from the shellfish "arkshell".