There are many kinds of aquatic plants, which are widely distributed. In the ponds or rice fields where crayfish are cultivated, the species suitable for crayfish mainly include Sophora alopecuroides, Haematococcus verticillata, Ceratophyllum, Alternanthera philoxeroides, duckweed, Elodea nutmeg, Potamogeton aquatica, Sophora japonica, Azolla, Sargassum japonicum, water spinach and so on. The following is a brief introduction to the characteristics and planting methods of several commonly used aquatic plants.

1. Elodea nuttallii

1. Advantages of Elodea nuttallii:

Elodea nuttallii is a high-quality, fast-growing and high-yield submerged plant with the characteristics of freshness, tenderness and crispness, which is an excellent natural bait for lobsters. Elodea nuttallii has the advantages of early germination and fast growth. Its leaves are small and not resistant to high temperature. It can be cultivated as long as there is no ice on the water surface. It can germinate when the water temperature is above 5℃, start growing at 1℃, and grow fast at 15℃. When the water temperature is above 3℃, the growth is obviously weakened, the algae leaves turn yellow and some plant tops will wither.

It can overwinter as a vegetative body in cold winter, and only it can provide an ideal place for lobster to grow, inhabit, shell and avoid enemies when other aquatic plants have not grown in the early stage. Elodea nuttallii has fresh and tender plants, soft leaves and good palatability, and its nutritional value is obviously higher than that of Sophora alopecuroides and Hydrilla verticillata. It is a high-quality feed that lobsters like to eat and is very suitable for the growth of lobsters. The biomass of Elodea nuttallii is usually the highest in April-May and October-November in the Yangtze River basin.

2. disadvantages of Elodea nuttallii

Elodea nuttallii has the disadvantages of not being able to withstand high temperature and growing vigorously. When the water temperature reaches 3℃, it basically stops growing, and it is easy to stink. Therefore, the coverage rate of this weed should be controlled within 2%, and farmers can plant it as a transitional weed.