How many grass carp fry should be released per acre?

Grass carp is one of China's traditional freshwater farmed fishes. It is easy to breed, has low cost, grows fast and has a high feed conversion rate, and is therefore favored by a large number of farmers. So when raising grass carp, how many fish fry should be placed per acre? Let’s learn more about it below.

How many grass carp fry should be released per acre?

The number of grass carp fry to be released per acre depends on many factors, including the size of the fry, the breeding environment, the breeding model , etc. For example, under conventional breeding models, usually 500-1000 grass carp fry can be raised per acre of water surface, and the fry size is 10-20 grams per fry. When mixed breeding with carnivorous fish , 300-500 grass carp can be released per acre of water surface, and 100-200 carnivorous fish such as sea bass, mandarin fish, etc. can be released at the same time. Therefore, the specific stocking density must be adjusted according to the specific breeding conditions.

What preparations should be done before releasing grass carp fry?

1. Pond selection

Choose a place with sufficient water source, good water quality, sheltered from the wind and facing the sun to build a pond with a moderate area for easy management and feeding. A certain thickness of silt should be laid on the bottom of the pond to provide a place for grass carp to live and forage.

2. Pond cleaning and disinfection

7-10 days before stocking the fry, choose a sunny noon to clean the pond with medicine. Quicklime or bleaching powder can be used for disinfection, and the amount per acre depends on the size and water depth of the pond. For example, the amount of dry pond cleaning is 25-30 kg per mu, and the amount of water pond cleaning is 40-50 kg per mu.

3. Pond Fertilizer

Before stocking, the pond needs to be fertilized to provide the fry with enough natural food. Organic fertilizers or biological agents can be used to cultivate plankton such as algae and zooplankton.

4. Select fish fry

Select fry that are healthy, active, and have no obvious injuries. The size of the fry should be consistent to facilitate their growth. For example, the size of grass carp fry should preferably be larger than 5 inches.

5. Temporary rearing of fry

The fry can be temporarily raised in a fry box. First, put the fry and the plastic bag into the pond. After about 20 minutes, gradually adjust the water temperature inside and outside the bag to the same, and then put the fry into the box.

6. Stocking operation

The time for stocking should be chosen on a sunny and windless day with the water temperature around 7-8°C. When stocking the seedlings, the temperature difference should be minimized as much as possible, and the oxygenated seedling bags should be placed in the water to allow them to adjust the temperature difference naturally. When releasing the fry, the temperature difference between the pond water and the container holding the fry should not exceed 2°C. If the temperature difference is too large, the water temperature should be tested and adjusted, and the fry can be released into the pond only after they have adapted.

In general, the number of grass carp fry to be released per acre depends on the specific breeding conditions. Of course, in addition to paying attention to density, the above pre-stocking preparations should also be taken seriously, which can provide a good growth environment for grass carp fry and improve the survival rate and growth rate of the fry.