Live crabs can be eaten if they are frozen and then thawed, they just don't taste as good as fresh crabs.
If you buy them the same day and eat them the next day, you don't need to freeze them, just refrigerate them. A day's worth of frozen crab is still alive.
When freezing, crabs must be sealed in a plastic bag to prevent evaporation of water. At minus 18 degrees Celsius, crabs are able to retain their shelf life for about half a year. Thawing is done by soaking in water, waiting until the crab claws can be bent freely, and steaming for 20 minutes on the pot before serving. It's best to eat it with vinegar and ginger, which can remove the fishy smell and refresh the taste; and secondly, it can drive away the cold.
The crab flavor is fresh and fragrant, belongs to the cold ingredients, the body cold people should not eat too much.
The crabs are fattest in the fall and thinnest in the summer. The pike crabs from the northern waters are large and meaty, and are the best of the crabs.