Detailed Explanation of Freshwater Fish Farming Knowledge and Key Aquaculture Techniques

Freshwater fish farming is a production method in which fish fry are stocked into a water body with a certain level of feeding and management, or the fish resources in a water body are bred and protected, so as to obtain high fish yields. At present, China has more than 30 species of freshwater fish for farming. According to the characteristics of the farmed fish, water body conditions, and farming measures, freshwater fish farming is divided into the following methods:

Classification according to the water temperature requirements of the farmed fish

Warm-water fish farming, generally at a water temperature of 15-30°C, such as common carp, grass carp, silver carp, bighead carp, crucian carp and blunt snout bream, etc.; Cold-water freshwater fish farming: generally the suitable temperature is 10-20°C, such as rainbow trout, lenok, etc.; Hot-water fish farming: generally the suitable temperature is 18-30°C, such as tilapia, freshwater pomfret, etc.

Classification according to farming water body conditions, etc.

According to farming water body conditions, fish species and sizes, water area types and farming measures, freshwater fish farming is further divided into the following methods:

1. Still-water fish farming and flowing-water fish farming.

2. Monoculture, polyculture and supplementary stocking.

3. Pond fish farming, rice-field fish farming, river fish farming, lake fish farming, reservoir fish farming, cage fish farming, purse seine and pen fish farming, and industrial fish farming, etc.

4. Intensive farming, semi-intensive farming, extensive farming, etc.

Pond Fish Farming Techniques

Pond fish farming is the fish farming method used in most areas of China. At present, its output accounts for more than 60% of freshwater fish farming, and it has the characteristics of small investment, large returns, quick results and stable production.

1. Area: generally the area of an adult fish pond is 5-10 mu, so that it is easy to manage. Brood fish ponds, fry ponds and fingerling ponds are preferably 3-5 mu.

2. Water depth: generally the water depth of an adult fish pond is 2-3 m. In the north, overwintering ponds are preferably 1.5-2 m below the thickest ice layer in severe cold. The water depth of fry ponds and hatching ponds is preferably 1.0-1.5 m. Fingerling ponds generally require a water depth of 1.5-2.0 m.

3. Water quality: abundant water sources and good water quality are the fundamental conditions for fish farming.

4. Requirements for the bottom soil: the bottom soil of the pond is best if it is loam or sandy loam, followed by clay.

Preparatory work before stocking

Renovate the pond, remove weeds and impurities at the bottom of the pond, and level the pond.

1. Pond clearing and disinfection

①Traditional pond clearing: that is, draining the water in winter, and removing harmful organisms and improving the bottom soil through freezing, drying and sun exposure of the pond bottom.

②Chemical pond clearing: quicklime or bleaching powder can be used.

2. Filling with water and cultivating water quality

After the pond is disinfected, wait until the toxicity of the drug disappears, then fill with fresh water. 7-10 days before stocking the fry, apply base fertilizer to cultivate water quality.