Crayfish, also known as Procambarus clarkii, belongs to Crustacea, Decapoda, Reptilia and Procambarus, and is native to North America. Nowadays, as the main culture method of Procambarus clarkii, the comprehensive culture of rice and shrimp has accounted for 70% of its culture area. But in this mode, the feeding of Procambarus clarkii is generally irregular. Unreasonable feeding methods not only lead to feed waste and reduce production efficiency, but also destroy the water environment and lead to frequent diseases.

First, eating habits

Procambarus clarkii is omnivorous. In the wild, large aquatic plants, algae, debris, zooplankton, rotifers, aquatic insects and so on will eat it. Although Procambarus clarkii feeds all year round, the feeding intensity of this species varies greatly in different seasons, with high feeding intensity in spring, summer and autumn and low feeding intensity in winter. During the day, the feeding of Procambarus clarkii is mainly concentrated in the morning and evening.

Second, the daily feeding amount.

The daily feeding amount of Procambarus clarkii is based on the principle of eating up, eating up and leaving no residual bait, and is adjusted according to the weather, water quality, density and different growth stages and physiological periods of Procambarus clarkii. Generally speaking, for fresh feed, the feeding amount of young shrimp is 8% ~ 10%, and the feeding amount of adult shrimp is 6% ~ 8%; In the compound feed, the feeding amount of young shrimp is 4% ~ 6%, and that of adult shrimp is 3% ~ 5%. The consumption of shrimp should be reduced before molting and increased after molting.

Third, the way of feeding.

1, rice and shrimp rotation

The alternate mode of planting rice and raising shrimp in alternate years is rice-shrimp rotation. In this model, April-May every year is the seedling stage, so it is generally necessary to apply more base fertilizer and topdressing in time to cultivate zooplankton such as rotifers and copepods. At this time, aquatic insects larva feed can be fed less. The growth period is from June to August. At this time, shrimps grow longer and flourish, so they should be fed enough feed. The weight gain period is from September to 65438+ 10, which is the fattening period of shrimp. Feed should be mainly high-protein feed and animal bait, and shrimp can be caught at this stage. The overwintering period is from 165438+ 10 to March of the following year, when the temperature drops, the consumption of shrimps decreases, and the shrimps usually stop eating when the water temperature is lower than 10℃.

2. Rice and shrimp cultivation (continuous cropping)

In China, the main producing areas of crayfish are mainly concentrated in the Yangtze River valley, and generally only one season of rice is produced each year. According to the characteristics of rice planting in this area, parent or egg-holding shrimps are generally stocked in the circular ditch of rice field before or 1 ~ 2 months after rice harvest, and the parent shrimps are caught in April-May of the following year, and the adult shrimps are caught in August-September. At this time, some adult shrimps can be left as parent shrimps for the next round of rice and shrimp culture.

Fourth, feeding methods

The feeding method should follow the principle of "timing, quantification, quality determination and positioning". Feed regularly twice a day in the morning and evening, and the feeding amount is 20% and 80% of the daily feeding amount respectively. The compound feed of Procambarus clarkii must be balanced in nutrition, attractive and stable in quality, and the fresh feed must be kept fresh and not spoiled. Because the activity of Procambarus clarkii is weak, the feed should be evenly distributed along the beach near the ring ditch and the fields beside the ditch, and it is not necessary to feed it in the ring ditch.