The scientific name of the small clam shell is triangular clam.

The triangle clam is commonly known as river clam, pearl clam, freshwater pearl clam, triangle clam, and its scientific name is Hyriopsis cumingii. Freshwater bivalve molluscs, belonging to the class Bivalvia, the family Mucilidae, and the genus Scalyptus.

Widely distributed in Hunan, Hubei, Anhui, Jiangsu, Zhejiang, Jiangxi and other provinces, especially in Dongting Lake and medium-sized lakes in my country.

The spinnaker clam shell is large and flat, with a black or tan shell surface, thick and hard, nearly 20 cm long, and a sail-like rear wing extending upward from the back edge, giving the clam a triangular shape. The back spine has several oblique thick ribs composed of nodular protrusions. The nacre layer is thick and lustrous. The hinge is well developed. The left shell has 2 pseudo-main teeth and 2 lateral teeth of different sizes, and the right shell has 2 pseudo-main teeth and 1 lateral tooth. Dioecious.