Horse Knife Meat, a Chinese medicine, refers to the meat of bivalve mollusks such as Megalonaias nervosa and Sinanodonta woodiana. Megalonaias nervosa is mainly found in Jiangsu, Anhui, Zhejiang, Jiangxi, Hubei, Hunan, etc. Sinanodonta woodiana is distributed in Heilongjiang, Hebei, Shandong, Jiangsu, Anhui, Zhejiang, Jiangxi, Hubei, Hunan, etc. It has the effects of clearing heat and improving vision. It is used to treat diabetes, blurred vision, and excessive uterine bleeding in women.
【Appearance of Horse Knife Meat】
1. Megalonaias nervosa
Megalonaias nervosa is a larger species of bivalve mollusk, with a shell length of about 70mm, shell height of about 35mm, and shell width of about 25mm. The shell is thick and hard. The front part of the shell is extremely swollen, and it rapidly narrows in height and width towards the back, giving it a triangular wedge shape. There is a depression behind the swollen part of the shell, located approximately in the middle of the shell.
The apex of the shell is located at the anterior edge, high and swollen, often with a brown surface due to erosion, and with concentric circles of growth lines. The hinge is well-developed, with 2 pseudo-cardinal teeth and 2 lateral teeth on the left valve, the anterior pseudo-cardinal tooth is leaf-shaped, the posterior pseudo-cardinal tooth is triangular cone-shaped with fine cracks on the top, and the 2 lateral teeth are slender and parallel. The right valve only has 1 triangular cone-shaped anterior pseudo-cardinal tooth and 1 lateral tooth, with traces of the posterior pseudo-cardinal tooth.
2. Sinanodonta woodiana
Sinanodonta woodiana has a shell length of up to 170mm, shell height of 44mm, and shell width of 39mm. The shell is thick, slightly inflated, asymmetrical on both sides, elongated, and shaped like a spear. Its length is 4-5 times its height. The top of the shell is slightly swollen, lower than the dorsal edge, often eroded, and located near the anterior edge, about 1/10 of the total length of the shell. The anterior margin is blunt and round, the anterior dorsal edge is straight, the posterior dorsal edge gradually slopes downward at half the length of the shell, the ventral edge is straight, and the middle part is slightly concave with a slightly round or sharp angle on the posterior edge. The umbonal area is elongated and well-developed.
The shell surface is grayish-brown with fine growth lines. There are arranged coarse short granular brown lines between the growth lines in the middle of the shell. There are also sawtooth-like brown lines at the shell apex, hence the name Sinanodonta woodiana. The hinge is well-developed, with 2 slightly triangular cone-shaped pseudo-cardinal teeth and 2 long blade-like lateral teeth on the left valve, and 2 pseudo-cardinal teeth and 1 lateral tooth on the right valve.
【Habitat Distribution】
Megalonaias nervosa: It mainly inhabits lakes or rivers with muddy or sandy bottoms, especially in fast-flowing water. It feeds on tiny organisms and plant debris. It is distributed in Jiangsu, Anhui, Zhejiang, Jiangxi, Hubei, Hunan, etc.
Sinanodonta woodiana: It inhabits rivers, lakes, and ponds with muddy or sandy bottoms. It is distributed in Heilongjiang, Hebei, Shandong, Jiangsu, Anhui, Zhejiang, Jiangxi, Hubei, Hunan, etc.
