1. Flying crabs belong to the same kind of crabs, but live in different sea areas. For example, swimming crabs produced in Liaoning are often called flying crabs, while those produced in Donghai, Zhejiang are called swimming crabs.

2. The shell and appendages of Scylla serrata are blue-green, the head and breastplate are slightly oval, the surface is smooth, the center is slightly convex, the surface of the carapace has obvious H-shaped depression, the forehead has four big teeth, the claw feet are smooth, the crab claws are asymmetrical and have thorns, but the hind feet have no spikes.