Clams can be eaten normally and have rich nutritional value. However, it is recommended not to eat black things in clam meat. The black thing on the body of Meretrix meretrix is mud in the sea or excrement of Meretrix meretrix, or internal organs of Meretrix meretrix, which contains a lot of cholesterol, some sediments, bacteria and metabolites, and has a bad smell. Moreover, these clams have not been tested and may contain parasites, heavy metals and so on. If you want to eat it, you'd better cook it at high temperature first.

Clams belong to mollusk phylum, bivalve, heterodonta, cladocera, claudiodea, Claudioside. There are warm water species and hot water species in this family, which are distributed in all oceans of the world. More than 30 species have been found in China's coastal areas, most of which live in the shallow sea bottom within 100 meters of the intertidal zone and subtidal zone in the middle and lower reaches, and a few can live in the deep sea above 100 meters and live in caves. Clam animals have high economic value, tender and delicious meat and rich nutrition, and are also the main species of beach culture in China.