Grass carp from Dongping Lake

Grass carp from Dongping Lake

　　Grass carp is the only species in the genus Ctenopharyngodon of the subfamily Leuciscinae under the family Cyprinidae, commonly known as “鲩” (huàn), and colloquially referred to as “grass green” or “thick one,” among other names. Its body is roughly cylindrical, with a slightly flattened head and a laterally compressed tail; the mouth is arched and toothless; the upper jaw is slightly longer than the lower jaw; the body is a linear tea-yellow color, with a bluish-gray back and grayish-white belly, the pectoral and ventral fins tinged with grayish-yellow, and the other fins light gray. It is a unique fish species in Dongping Lake. Before the 1960s, grass carp had the highest density and grew best. In 1956, a couple operating a fishing boat could catch over a hundred tons of fish a year, mainly grass carp and crucian carp. In 1964, a giant grass carp measuring 1.5 meters in length and weighing over 50 kilograms was caught in the lake.

　　Grass carp prefer the lower water layers and areas near the shore rich in aquatic plants. They are lively, swim fast, and often forage in groups. As typical herbivorous fish, they primarily feed on bitter grass and submerged vegetation, especially gramineous plants. They mature at 3–4 years of age, but since they cannot spawn in still water, they must be placed in flowing, live water. Fry can be artificially bred through induced spawning. Due to the easy availability of fry, simple diet, abundant water sources, rapid growth, and delicious meat, grass carp have long been a major cultured fish species in the rivers and lakes of Dongping.

　　Dongping Lake is rich in diverse aquatic plants, making it particularly suitable for the growth and development of grass carp. In pond aquaculture and net cage farming in Dongping Lake, grass carp account for more than half. The annual yield reaches over 5,000 tons. Grass carp are prone to disease, so proper prevention and control measures must be taken during breeding and production.