a kind of sea crab. That is, crickets, commonly known as blue crabs and swimming crabs. The pincers are strong and asymmetrical, and the fourth pair of legs are like paddles, which are suitable for swimming. The common Japanese horseshoe crab is the main edible crab.

Fujian, Zhejiang, Taiwan Province area refers to a local common name of decapod crabs. Such as: Gao Ji (Scylla serrata), Shi Ji (Japanese crab), Hong Hua Ji (rusty crab) and so on.

The above is from Baidu Encyclopedia. You can go to the Encyclopedia for details.

1 The yellow things in the shells of the clams and crabs are crab paste, the red things are crab seeds (the paste is for male crabs and the seeds are for female crabs), and the white things are respirators, so you can't eat them.

2. The feces of the midge and crab don't grow in front of the shell. After peeling, they are on the shell, and between the eyes is the crab's stomach. Obviously, there is a bag of dirt.

3 The white side of the crab navel before peeling is triangular or oval. The triangle is male and the ellipse is female. This is also a way to distinguish between male and female.