There are 2,000 species of fresh water, mainly belonging to the family Pinctada and the family Pinctada in the suborder Pinctada. In foreign countries, the species of mussels and pearl mussels are called mussels, and the species of clam and salamander are called fingernail clams. Oncomelania hupensis the largest kind of shellfish in the world, and there are about 12000 recorded freshwater species in the world.

Be distributed

Due to the uneven distribution of freshwater shellfish in the world, and the different degrees of research and attention paid by countries around the world to the conservation biology of freshwater shellfish, China and the United States are considered to be the countries with the richest biodiversity of freshwater shellfish. ?

Because of China's special position in the evolution of the earth, China is rich in species, and there are many unique species including living fossils, so the diversity of invertebrates in China, especially freshwater shellfish, is an important part of the global species diversity. There are 3,500 species of molluscs recorded in China, accounting for 3.5% of the world. Among them, there are 65,438+065,438+0 genera and 24 endemic species of freshwater bivalves.