White clam, small and round, with a high arch shell, rough and thin surface and sharp axe feet (that is, the meat inside), tastes ordinary and is cheap. Some places are called scorpions.

Meretrix meretrix is small, slightly flat, with patterns, slightly rough shell surface and thin wall. It is common in the market and mostly occurs in the southern waters.

Meretrix meretrix is authentic only when it is produced in Rudong. Qianlong once named it: the freshest in the world. It has a huge size, and the largest diameter can reach about 5CM. Skin care products in 1980s: clam oil used big mussel shells as containers, because mussel shells are hard and thick, and clam shell is fat, and its shape is authentic axe-shaped. It tastes good and the price is slightly higher. Cold can be eaten raw to remove fire.

Generally, it is enough to raise 1 day in salt water for desanding.