When the temperature rises, zooplankton such as cladopods multiply in large quantities, and cladopods will feed on single-celled algae and organic debris at the opening of shrimp and crab seedlings, and will quickly consume oxygen in the water body, resulting in deterioration of water quality.
With a dry weight crude protein content of 55% and high nutritional value, it is a biological bait for the seedling and larval stages of a variety of fish and special aquaculture species (such as green shrimp). When the river crab grows to the stage of the crab, due to the change of living habits, it will no longer actively feed on cladopera.
In 2 March, the size of the stocked juvenile crabs was (130 150) kg, and the stocking capacity was (800 1000) 667 m2;In January and February, the size of green shrimp fry was (1500 2000) kg, and the stocking capacity was (20000 25000) only 667 m2;In May, the size of stocking green shrimp and shrimp holding eggs was (200 250) kg, and the stocking amount was (0.15~0.2）kg/667 m2。It should be selected in the early morning or evening of a sunny day, and the pond water should be taken for trial breeding before stocking, and when it is confirmed that the pond water has no adverse effect on the seedlings, the seedlings should be stocked. Shrimp fry fishing, transportation and stocking should be operated with water.
In the early stage of breeding, amino acid fertilizer and water paste and chlorella were applied to prevent and control moss. In the early stage of cultivation (March and May), the water transparency was controlled at (25 30) cm, the middle stage (June and July) was controlled at 30 cm, and the transparency in the late stage (August and October) was controlled at (30 35) cm. Dissolved oxygen was kept above 5 mg L, and EM bacteria and Bacillus subtilis were used every 10 days during the pH month6 Spray Bacillus, lactic acid bacteria, and EM bacteria every 7 days in OctoberIn the rainy season, when there are continuous cloudy days, Clostridium butyricum is selected instead of Bacillus for water transfer. In the later stage of breeding, potassium persulfate was applied once every (10-15) d.
At temperatures higher than 15 and lower than 30, the over-propagated cladopods in the river crab pond were supplied to green shrimp seedlings and adult shrimp for feeding, which could effectively reduce the density of cladoperatops and achieve the purpose of "shrimp farming with insects".