2, crab dead half an hour can eat.

3, crab dead five hours can still eat.

4, crab dead four or five hours can still eat.

1. Crabs can't be eaten after five hours of death.

2. There is no problem with quick-freezing or eating crabs before they are dying, but after the crabs are dead, they will produce histamine, which is toxic and heat-resistant, so the dead crabs can not be eaten, and you can't eat groundnuts, pomegranates and grapes when you eat crabs.